{"title":"Flatteners, Reducers \u0026 Extenders","description":"","products":[{"product_id":"1-25-1-6x-extender-q-for-takahashi-refractors","title":"Takahashi 1.25\" 1.6X Extender-Q for Takahashi Refractors","description":"\u003cp\u003eThis dual purpose Takahashi optical system is both a 2\" 1.6x Barlow and a field flattening photographic tele-extender designed for use with Takahashi FSQ-106\/Sky 90 refractors.\u003c\/p\u003e\n\u003cp\u003eThe 1.25\" Extender-Q is a visual and photographic amplification device designed for use with older Takahashi FSQ-106N and Sky 90 refractors. It changes the FSQ-106N from a 530mm f\/5 to an 850mm f\/8 and provides a 44mm image circle with a 3° field. The Sky 90 changes from a 500mm f\/5.6 to an 800mm f\/9. However, tests have shown that the Extender-Q will give you similar 1.6x magnification and focal ratio results with every Takahashi refractor, and not just the fast focal ratio FSQ-106 and Sky 90.\u003c\/p\u003e\n\u003cp\u003eThe Extender-Q threads into the Takahashi focuser drawtube before the 1.25\" eyepiece adapter and so cannot be used with non-Takahashi scopes.\u003c\/p\u003e\n\u003cp\u003eThis extender is not a simple two-lens achromatic Barlow lens, but rather a sophisticated optical amplification device using five lenses in three groups that functions as both a visual Barlow and a photographic tele-extender. Its five-element optical system is fully multicoated for maximum light transmission and contrast. The Extender-Q produces a flat, color free, extremely high contrast image that can be used for high magnification lunar and planetary visual observation or photography and CCD imaging.\u003c\/p\u003e\n\u003cp\u003eAn additional advantage of the Extender-Q is that it corrects the image in the ultraviolet portion of the spectrum that is invisible to the eye, but is easily recorded by CCD cameras. Stars that radiate strongly in the ultraviolet appear closer to their naked-eye visual appearance when imaged on a CCD camera through the Extender-Q. They do not have a bloated appearance on photos due to their normally invisible UV component being recorded by the CCD camera and added to the visual image. This feature only adds to the photo\/visual capabilities of Takahashi scopes.\u003c\/p\u003e\n\u003cp\u003eThe Extender-Q threads into the focuser drawtube, in place of the 1.25\" eyepiece adapter (which is unthreaded from the focuser drawtube and reinstalled on the end of the Extender-Q). Several extension tubes in the Extender-Q body add the needed extra light path distance to allow eyepieces and a 1.25\" star diagonal to focus. An optional 2\" adapter #TEQ0002, shown below, threads into the end of the Extender-Q in place of the 1.25\" adapter to let you use a 2\" star diagonal and 2\" eyepieces with the Extender-Q.\u003c\/p\u003e\n\u003cp\u003eThe maximum length of the Extender-Q (5.5\") is only used for photography and straight-through visual observing. With a star diagonal, two of the extender tubes in the Extender-Q body are removed, shortening the Extender-Q length to 3\". Rubber grip rings on each section make it easy to assemble and disassemble the unit.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBarrel Size\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eLength\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1.6x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e13 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":40221636329545,"sku":"XTND-Q","price":640.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/3861_1.jpg?v=1662966778"},{"product_id":"0-8x-reducer-photographic-field-flattener-for-tv-85-pronto","title":"TeleVue 0.8X Reducer\/Photographic Field Flattener for TV-85\/Pronto","description":"\u003cp\u003eThis 0.8X reducer\/field flattener assembly converts the 600mm focal length f\/7 TeleVue TV-85 refractor into a 480mm f\/5.6 telephoto lens for faster astronomical and terrestrial photography. It also converts the 480mm f\/6.8 TeleVue Pronto into a 380mm f\/5.4 lens, and can be used for a similar purpose with any other manufacturer's 400mm to 600mm focal length refractor that has a 2\" focuser. In addition to reducing the focal length of the telescope and thereby increasing the photographic speed, the system flattens the normal field curvature inherent in all refractors to provide images that are sharply focused out to the very corners of the 35mm frame. Stars look sharp and point-like all the way across the field. You don't have to worry about photos that are sharp in the center and blurry at the edges.\u003c\/p\u003e\n\u003cp\u003eThe fully multi-coated 3-lens assembly inserts directly into a 2\" focuser and accepts a standard T-ring for connecting a 35mm camera. A review in \u003cem\u003eSky \u0026amp; Telescope \u003c\/em\u003esaid, \"This accessory is a must-have for someone planning to use the TV-85 photographically.\"\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003cbr\u003e\n\u003c\/h2\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"TeleVue","offers":[{"title":"Default Title","offer_id":40221636919369,"sku":"1348","price":403.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/TRF_2008_0.8xRFRef400_600_copy.jpg?v=1723659947"},{"product_id":"eyepiece-projection-adapter-needs-t-ring","title":"Takahashi Eyepiece Projection Adapter, Needs T-Ring","description":"\u003cp\u003eConsists of three parts for eyepiece projection photography with Takahashi refractors only. The normal 1.25\" Takahashi eyepiece holder is unscrewed from the telescope drawtube and replaced by a special compression ring 1.25\" eyepiece holder from the TCA-4. A 1.25\" eyepiece is inserted into the compression ring (0.965\" eyepieces can be used by adding optional 0.965\" adapter #TCA9AD) and locked in place by tightening the ring. The TCA-4 body slips over the eyepiece and is in turn locked into place on the compression ring by thumbscrews. An optional T-ring attaches to the telescoping inner tube of TCA-4. The inner tube can be moved in and out of the TCA-4 body to allow the projection distance to be varied from 100mm to 130mm. The projection distance is locked in by thumbscrews on the TCA-4 body. The orientation of the camera can be changed from horizontal to vertical by loosening the thumbscrews at the front of the TCA-4 body, rotating the body to the desired angle, and retightening the thumbscrews. The variable projection distance design allows you to change the magnification to vary the size of the image by 30% without the need to change to a different focal length eyepiece. Needs optional T-ring.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eProjection Distance\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e100mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":40221639409737,"sku":"TCA-4","price":352.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/4156_1.jpg?v=1662966871"},{"product_id":"0-8x-reducer-field-flattener-corrector-for-photography-for-mewlons","title":"Takahashi 0.8X Reducer\/Field Flattener\/Corrector for Photography for Mewlons","description":"\u003cp\u003eThis fully-multicoated visual\/photographic focal reducer for the Takahashi Mewlon Dall-Kirkham reflectors shortens each telescope's focal length and effective focal ratio by a factor of 0.8x.\u003c\/p\u003e\n\u003cp\u003eWith the reducer in place, the 8.3\" Mewlon 210 changes from a 2415mm focal length f\/11.5 system to a 1961mm focal length f\/9.3. This increases the image circle from 18mm at the focal plane at f\/11.5 to 39mm at f\/9.3 with the reducer in place. The field of view is 1.2° using the reducer.\u003c\/p\u003e\n\u003cp\u003eBy the same token, the 9.8\" Mewlon 250 changes from a 3000mm focal length f\/12 to a 2307mm f\/9.2 system. This increases the image circle from 21mm at the focal plane at f\/12 to 42mm at f\/9.2, with a 1° field of view.\u003c\/p\u003e\n\u003cp\u003eThe 11.8\" Mewlon 300 changes from a 3572mm focal length f\/11.9 to a 2739mm f\/9.1 system, with the image circle increasing from 25mm to 42mm. With the reducer, the field of view is 45 arc minutes in diameter.\u003c\/p\u003e\n\u003cp\u003eIn addition to reducing the Mewlon focal length and focal ratio, this reducer also acts as a field flattener and corrector to reduce the coma inherent in the Dall-Kirkham design as well as the curvature of field that put stars at the edge of the field subtly out of focus. Coma is reduced and stars remain focused to the edges of the field with the reducer in use, allowing large photographic blowups that stay sharp all across the print.\u003c\/p\u003e\n\u003cp\u003eThe reducer has a 2\" barrel that slips into the Mewlon focuser. A safety groove machined into the barrel helps keep the reducer and attached camera from falling should the focuser thumbscrew accidentally loosen during use. The camera side of the reducer has standard 42mm photographic T-threads for connection to your camera.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e8 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":40221645733961,"sku":"TMC1800","price":530.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/5372_1.jpg?v=1662967080"},{"product_id":"large-field-corrector-for-ccd-imaging-with-np-101is-np-127is","title":"TeleVue Large Field Corrector for CCD Imaging with NP-101is\/NP-127is","description":"\u003cp\u003eThis auxiliary multicoated lens system sharpens 35mm and large format CCD images taken through the TeleVue NP-101is and NP-127is imaging system refractors only. The lens flattens the normally slightly curved refractor field to provide tightly-focused pinpoint star images across the entire field for deep space photography. It does it without changing the effective focal length or focal ratio of the scope. It is recommended for cameras using large format CCD chips, such as the SBIG Research Series STL-11000M and 11000CM which have CCD chips the size of a 35mm negative, as well as those cameras with still larger chips (greater than the 36mm x 24.7mm chips of the STL-11000 models).\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"TeleVue","offers":[{"title":"Default Title","offer_id":40221652746313,"sku":"1360","price":343.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/12389_1.jpg?v=1662967327"},{"product_id":"f-6-3-focal-reducer-for-schmidt-cassegrains","title":"Antares f\/6.3 Focal Reducer for Schmidt-Cassegrains","description":"\u003cp\u003eThis focal reducer and field flattener consists of a four-element multicoated 40mm lens in a metal cell. It threads onto the rear cell of 5\" to 16\" Celestron and Meade Schmidt-Cassegrain telescopes, making it possible to have a dual focal ratio instrument without sacrificing image quality. The reducer\/corrector duplicates the rear cell thread of the telescope, allowing you to attach all standard rear cell visual and photographic accessories to the reducer. The reducer\/corrector converts the f\/10 focal ratio of Celestron C5, C8, C9¼, and C11 telescopes (and all Meade 8\" and larger f\/10 telescopes) to f\/6.3. The f\/11 C14 telescope becomes an f\/7. When used for astrophotography, it reduces exposure times by a factor of 3, with an actual field diameter of 1.5\" at the film plane.\u003c\/p\u003e\n\u003cp\u003eA rubber grip ring on the body allows for easy installation of the made-in-Canada reducer\/corrector on your scope, even when you are wearing gloves.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e4 0z.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Antares","offers":[{"title":"Default Title","offer_id":40221652844617,"sku":"8310","price":99.95,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/12637_1.jpg?v=1662967332"},{"product_id":"0-5x-focal-reducer-for-celestron-meade-and-orion-ccd-imaging-cameras","title":"Antares 0.5X Focal Reducer for Celestron, Meade, and Orion CCD Imaging Cameras","description":"\u003cp\u003eThis Antares 1.25\" 0.5x focal reducer lens (tele-compressor) is used under the Orion brand name to thread into the nosepiece of Orion StarShoot Solar System cameras and StarShoot Deep Space Color Imaging Camera. It can also be used with any other small chip CCD camera having a 1.25\" nosepiece, such as the Celestron NexImage, Meade DSI, etc. It is an inexpensive way to more than double the field of view and halve the photographic magnification of such cameras.\u003c\/p\u003e\n\u003cp\u003eThis allows you to image more of the lunar surface in a single exposure for more dramatic views of our nearest solar system neighbor and gives you four times the sky area in your deep space Images. The reducer is not recommended for planetary imaging, as it will make the disc of the planet smaller, which is usually the reverse of what you are trying to accomplish when imaging a small and distant planet.\u003c\/p\u003e\n\u003cp\u003eThe Antares reducer will also work with any CCD camera using a 1.25\" nosepiece that is threaded for 1.25\" filters. It will work with both solar system (lunar\/planetary) imagers and deep space imagers. It effectively reduces the focal length of the telescope by half with all CCD cameras. This increases the area imaged by your camera by a factor of 4.\u003c\/p\u003e\n\u003cp\u003eThe larger imaging area allows you to capture larger star fields and deep-sky objects that may not normally fit entirely onto your deep space camera's imaging CCD. With the StarShoot II Solar System camera (and other lunar\/planetary imagers), it effectively changes the image size recorded by the camera from the equivalent of that seen through a 6mm eyepiece to that of a 12mm eyepiece. This permits wider field imaging of the Moon (as well as imaging the sun, if you use the proper solar filter over the objective of your scope).\u003c\/p\u003e\n\u003cp\u003eThe Antares reducer uses a two-element achromatic lens, with antireflection coatings on all air-to-glass lens surfaces for maximum light transmission. The lenses are set in an anodized aluminum cell that is threaded to accept 1.25\" filters. The Antares reducer requires 43mm of additional inward focus travel when used with the Orion StarShoot II Solar System Camera and 52mm of inward focus travel when used with the Orion StarShoot Deep Space Color Imaging Camera II.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Antares","offers":[{"title":"Default Title","offer_id":40221654155337,"sku":"ORSSFR","price":24.95,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/13326_1.jpg?v=1662967391"},{"product_id":"f-6-3-reducer-corrector-for-schmidt-cassegrains","title":"Celestron F\/6.3 Reducer\/Corrector for Schmidt-Cassegrains","description":"\u003cp\u003eThis combination focal reducer and field flattener consists of a four-element multicoated 41mm lens in a metal cell. It threads onto the rear cell of 5\" to 16\" Celestron and Meade Schmidt-Cassegrain telescopes, making it possible to have a dual focal ratio instrument without sacrificing image quality. The reducer\/corrector duplicates the rear cell thread of the telescope, allowing you to attach all standard rear cell visual and photographic accessories. The reducer\/corrector converts the f\/10 focal ratio of Celestron C5, C8, C9¼, and C11 telescopes (and all Meade 8\" and larger f\/10 telescopes) to f\/6.3. The f\/11 C14 telescope becomes an f\/7. When used for astrophotography, it reduces exposure times by a factor of 3, with an actual field diameter of 1.5\" at the film plane.\u003c\/p\u003e\n\u003cp\u003eThe reducer\/corrector is supplied with full instructions and with plastic dust caps for both sides of the lens assembly. A rubber grip ring on the body allows for easy installation of the reducer on your scope, even when you are wearing gloves.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable class=\"table-open\" id=\"product-specs-list\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eLens Coating:\u003c\/td\u003e\n\u003ctd\u003eFully Multi-coated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial:\u003c\/td\u003e\n\u003ctd\u003eMachined aluminum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible:\u003c\/td\u003e\n\u003ctd\u003eCelestron Schmidt-Cassegrain telescopes (C5, C6, C8, C9.25, C11, C14) | No EdgeHD tubes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions:\u003c\/td\u003e\n\u003ctd\u003e56mm (2.2\") in diameter, 34mm (1.34\") long\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight:\u003c\/td\u003e\n\u003ctd\u003e4.3 oz (121.90 g)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCalifornia Residents\u003c\/td\u003e\n\u003ctd class=\"cali-prop65-warning\"\u003e\u003ca href=\"https:\/\/www.celestron.com\/products\/reducer-corrector#\"\u003eView Proposition 65 Warning\u003c\/a\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":40221656940617,"sku":"8325","price":199.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/3906_1.jpg?v=1662967471"},{"product_id":"2-1-6x-extender-qe-for-the-new-takahashi-fsq-106ed-fs-60c-refractors-only","title":"Takahashi 2\" 1.6X Extender-QE for the New Takahashi FSQ-106EDX4 Refractors Only","description":"\u003cp\u003eThe Takahashi Extender-QE is designed specifically for use with the new Takahashi FSQ-106EDX4 refractors only. It serves a dual purpose with that scope. It is both a 2\" 1.6x visual Barlow and a field-flattening photographic tele-extender. This extender is not a simple two-lens achromatic Barlow lens, but rather a refined five-element optical amplification device.\u003c\/p\u003e\n\u003cp\u003eThe 1.6x Barlow function is very useful with the fast focal ratio f\/5 FSQ-106EDX4 refractor, as it lets you use long focal length eyepieces without having their exit pupils exceed the maximum dilated size of your eye's pupil. It also provides a longer telescope focal length to let you achieve higher magnifications without having to resort to very short focal length\/short eye relief eyepieces.\u003c\/p\u003e\n\u003cp\u003eThe Extender-QE produces a flat, color free, extremely high contrast image that can be used for high magnification lunar and planetary visual observation or photography and CCD imaging. An additional advantage of the Extender-QE is that it corrects the image in the ultraviolet portion of the spectrum that is invisible to the eye, but is easily recorded by CCD cameras. Stars that radiate strongly in the ultraviolet appear closer to their naked-eye visual appearance when imaged on a CCD camera through the Extender-QE. They do not have a bloated appearance on photos due to their normally invisible UV component being recorded by the CCD camera and added to the visual image. This feature only adds to the photo\/visual capabilities of the Takahashi FSQ-106ED.\u003c\/p\u003e\n\u003cp\u003eIts five-element optical system is fully multicoated for maximum light transmission and contrast. There is a deep safety groove cut into the 2\" barrel on the telescope side of the Extender-NQ. This catches the \"New Q\" telescope's 2\" focuser thumbscrew and prevents the extender from slipping out of the focuser should that thumbscrew accidentally loosen while observing. Two chrome thumbscrews in the 2\" barrel on the eyepiece side of the extender hold eyepieces, star diagonals, and camera adapters firmly in place. Dust caps are provided for both ends of the XTND-QE to keep it dust-free when not in use.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eBarrel Size\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eLength\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e3.75\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1.6x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e12 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":40221660938313,"sku":"XTND-NQ","price":720.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/13967.jpg?v=1662967629"},{"product_id":"0-8x-reducer-lens-body-for-tv-102-and-tv-102iis-refractors","title":"TeleVue 0.8X Reducer Lens Body for TV-102 and TV-102iis Refractors","description":"\u003cp\u003eThis TeleVue 0.8x magnification multicoated auxiliary lens system reduces by 20% the focal length of the TeleVue TV-102iis and the TV-102 and other TeleVue 2\" focuser refractors. The field of view and lens speed of the telescope accordingly increases by 25%. For example, with a TV-102, the focal length decreases from 880mm to 704mm and the focal ratio shortens from f\/8.6 to f\/6.9. The reducer works with film and CCD formats up to standard 35mm size.\u003c\/p\u003e\n\u003cp\u003eThe reducer is optimized for the 55mm back focal length typical of 35mm SLR and digital SLR cameras that accept T-rings. To attach an optional T-ring to the back of the reducer, you will need either optional adapter #13TRA to use a standard T-ring or optional adapter #13CAW to use a Canon T-ring (the #13CAW eliminates the inner portion of Canon T-rings to provide a larger diameter opening for reduced vignetting). Attaching the SBIG STL11000 Research Series CCD camera will require an optional #13STL adapter.\u003c\/p\u003e\n\u003cp\u003eThe #1362 is constructed to work with 2\" focuser drawtube telescopes (such as the TV-102) as well as the threaded imaging system accessories of the TV-102iis refractor.\u003c\/p\u003e\n\u003cp\u003eIn addition to this #1362, imaging will require one of three combinations of some of the following accessories (which combination is used depends on the type of camera - see the system charts in the feature images below): \u003cbr\u003ea \u003ca href=\"\/televue-0-25-inch-64mm-spacer-ring_p14559.aspx\"\u003e#13T025 0.25\" spacer\u003c\/a\u003e, \u003cbr\u003ea \u003ca href=\"\/televue-0-50-inch-127mm-spacer-ring_p14561.aspx\"\u003e#13T050 0.5\" spacer\u003c\/a\u003e, \u003cbr\u003ea \u003ca href=\"\/televue-1-inch-254mm-spacer-ring_p14562.aspx\"\u003e#13T100 1.0\" spacer\u003c\/a\u003e, \u003cbr\u003ea \u003ca href=\"\/televue-canon-wide-mount-t-adapter_p12451.aspx\"\u003e#13CAW Canon wide T-adapter\u003c\/a\u003e, and Canon T-ring,\u003cbr\u003ea \u003ca href=\"\/televue-standard-t-ring-camera-adapter_p14558.aspx\"\u003e#13TRA standard T-ring adapter\u003c\/a\u003e, and an appropriate T-ring,\u003cbr\u003ea \u003ca href=\"\/televue-sbig-stl-11000-ccd-camera-adapter_p14557.aspx\"\u003e#13STL SBIG STL11000 camera adapter\u003c\/a\u003e, \u003cbr\u003eplus the imaging system adapter supplied with the TeleVue telescope. \u003cbr\u003eWhen using non-IS scopes (such as the TV-102) that have a 2\" focuser drawtube, an optional \u003ca href=\"\/televue-adapter-0-8x-reducer-2-inch-focuser_p14571.aspx\"\u003e#1363 adapter\u003c\/a\u003e is required in place of the imaging system adapter that is supplied with the TV-102iis and labeled part A in the system charts.\u003c\/p\u003e\n\u003cp\u003eThe system chart feature images below show the required order in which the #1362 and the other optional accessories should be assembled for proper operation.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e8 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"TeleVue","offers":[{"title":"Default Title","offer_id":40221661790281,"sku":"1362","price":446.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/14567.jpg?v=1662967659"},{"product_id":"adapter-to-use-0-8x-reducer-in-2-focuser-tv-102-np-101-or-np-127","title":"TeleVue Adapter to Use 0.8x Reducer in 2\" Focuser TV-102, NP-101, or NP-127","description":"\u003cp\u003eThis TeleVue 2\" focuser adapter lets you use the #1361 0.8x reducer with the 2\" focusers of TeleVue NP-101 and NP-127 refractors. It also lets you use the #1362 0.8x reducer with the 2\" focuser of the TV-102 refractor. The adapter lets you do prime focus astrophotography with these reducers using 35mm film cameras, 35mm format digital SLRs, and SBIG STL11000 Research Series CCD cameras.\u003c\/p\u003e\n\u003cp\u003eIn addition to this #1363, imaging will require one of three combinations of some of the following accessories (which combination is used depends on the type of camera - see the system chart feature image below): \u003cbr\u003ea \u003ca href=\"\/televue-0-8x-reducer-lens-body-for-televue-nagler-petzval-np-refractors_p13328.aspx\"\u003e#1361 0.8x reducer\u003c\/a\u003e or \u003ca href=\"\/televue-0-8x-reducer-lens-body-for-tv-102-and-tv-102iis-refractors_p14567.aspx\"\u003e#1362 0.8x reducer\u003c\/a\u003e, \u003cbr\u003ea \u003ca href=\"\/televue-3-8-inch-96-5mm-extension-tube_p14570.aspx\"\u003e#1364 3.8\" extension tube\u003c\/a\u003e, \u003cbr\u003ea \u003ca href=\"\/televue-0-25-inch-64mm-spacer-ring_p14559.aspx\"\u003e#13T025 0.25\" spacer\u003c\/a\u003e, \u003cbr\u003ea \u003ca href=\"\/televue-0-50-inch-127mm-spacer-ring_p14561.aspx\"\u003e#13T050 0.5\" spacer\u003c\/a\u003e, \u003cbr\u003ea \u003ca href=\"\/televue-1-inch-254mm-spacer-ring_p14562.aspx\"\u003e#13T100 1.0\" spacer\u003c\/a\u003e, \u003cbr\u003ea \u003ca href=\"\/televue-canon-wide-mount-t-adapter_p12451.aspx\"\u003e#13CAW Canon wide T-adapter\u003c\/a\u003e, and Canon T-ring,\u003cbr\u003ea \u003ca href=\"\/televue-standard-t-ring-camera-adapter_p14558.aspx\"\u003e#13TRA standard T-ring adapter\u003c\/a\u003e, and an appropriate T-ring, and\u003cbr\u003ea \u003ca href=\"\/televue-sbig-stl-11000-ccd-camera-adapter_p14557.aspx\"\u003e#13STL SBIG STL11000 camera adapter\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eThe system charts in the feature images below show the required order in which the #1363 and the other optional accessories should be assembled for proper operation. The #1363 adapter is used in place of the imaging system adapter, labeled part A in the system charts below, that is supplied with IS-system scopes.\u003c\/p\u003e\n\u003cp\u003eThe adapter is made of black anodized aluminum with internal anti-reflection threads for maximum contrast. A safety cut in the adapter's 2\" barrel engages the thumbscrew or compression ring of the telescope focuser to hold the adapter safely in the focuser should the thumbscrew or compression ring loosen during use.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"TeleVue","offers":[{"title":"Default Title","offer_id":40221661823049,"sku":"1363","price":69.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/14571.jpg?v=1662967660"},{"product_id":"astro-tech-2-field-flattener-for-imaging-with-astro-tech-and-tmb-refractors","title":"Astro-Tech 2\" Field Flattener for Imaging with Astro-Tech and TMB Refractors","description":"\u003cp\u003eNew for August 2021, thread on adatper tops to choose between 42mm T-threads and 48mm T-threads.\u003c\/p\u003e\n\u003cp\u003eNamed a \u003cem\u003e\u003cspan style=\"font-family: verdana; color: #990000;\"\u003eSky \u0026amp; Telescope Hot Product of the Year for 2010\u003c\/span\u003e, \u003c\/em\u003ethe Astro-Tech photographic field flattener reduces the normal field curvature inherent in all refractors to provide you with images that are sharply focused out to the very corners of your DSLR or large format CCD imager frame. Stars on your images look sharp and point-like all the way across the field. You don't have to worry about photos that are sharp in the center but out of focus at the edges. The field flattener also works surprisingly well with the 6\", 8\", and 10\" Astro-Tech Ritchey-Chrétien astrographic reflectors.\u003c\/p\u003e\n\u003cp\u003eAs \u003cem\u003eSky \u0026amp; Telescope \u003c\/em\u003epointed out in their Hot Product citation, \"With only a few noteworthy (and expensive) exceptions, refractors need optional field flatteners in order to deliver acceptable star images across the field of today's DSLR cameras. Custom-designed flatteners usually cost hundreds of dollars, but the Astro-Tech 2\" Field Flattener is only $139. Furthermore, it's designed for any refractor with a focal ratio between f\/6 and f\/8. And there are reports that helps flatten the field of Astro-Tech Ritchey-Chrétien astrographs. The flattener was reviewed in the September 2009 issue of \u003cem\u003eSky \u0026amp; Telescope, \u003c\/em\u003epage 38.\"\u003c\/p\u003e\n\u003cp\u003eDesigned to work purely as a field flattener for imaging, and not simultaneously as a focal reducer or telecompressor, the 2\" Astro-Tech field flattener does not change the focal length or focal ratio of your telescope. It is not designed for visual use, having photographic T-threads only and no provision for using a star diagonal or eyepieces.\u003c\/p\u003e\n\u003cp\u003eA separate review in \u003cem\u003eSky \u0026amp; Telescope \u003c\/em\u003emagazine of the Astro-Tech field flattener and the Astro-Tech AT106 refractor said the field flattener was \"extremely easy to use with any SLR camera. You simply screw on the appropriate T-ring, connect your camera, and slip the flattener into the AT106's 2-inch focuser. Daylight shots made two things immediately apparent - the field flattener does not change the telescope's focal length (it's a true zero-power flattener), and it sharpens images at the edge of the field . . . At night, star images in the corners of my Nikon D300's APS-format frame, while vastly better than those recorded without the flattener, still showed a slight elongation . . . By focusing at a point slightly off center, thus balancing the imaging performance between the center and edge of the field, I could fill the frame with nice, round star images. For photographers shooting day or night, the flattener is well worth its current $150 price.\"\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"\" style=\"float: right; margin-left: 15px; margin-right: 15px; border-width: 1px; border-style: solid;\"\u003e\u003c\/p\u003e\n\u003cp\u003eWhile not specifically designed to work with Ritchey-Chrétien astrographs, images taken with the field flattener by Astro-Tech R-C owners have shown that the Astro-Tech 2\" field flattener works remarkably well with these advanced coma-free reflectors as well as with refractors. Comments like \"Works great on my AT8RC. Won't image without it,\" and \"Works well with my AT6RC,\" show up regularly in on-line imaging forums. An optical analysis and ray tracing of the field flattener was done in ZEMAX and applied to the R-Cs by Roger Ceragioli, the noted optical designer who did the final optimization of the design of the Astro-Tech Ritchey-Chrétiens. Here is what he had to say about the #AT2FF, \"My conclusion, which seems supported by what users are saying, is that you don't need any other field flattener. This one performs well over a 40mm image circle in all three small RCs (6\", 8\", and 10\").\"\u003c\/p\u003e\n\u003cp\u003eThe 2\" barrel of the fully multicoated dual-element Astro-Tech field flattener inserts directly into your scope's 2\" focuser drawtube. A groove machined into the field flattener barrel engages the thumbscrew or compression ring of your focuser to act as a safety stop. This prevents the field flattener and camera from falling to the ground should the thumbscrew or compression ring accidentally loosen during use.\u003c\/p\u003e\n\u003cp\u003eThe AT2FF now comes with threaded adapter tops for 42mm x 0.75mm pitch , or 48mm x 0.75mm pitch, T-2 photographic T-threads on the observer\/camera side of the black anodized field flattener accept a standard T-ring for connecting a 35mm or DSLR camera to the field flattener. They also allow direct connection to many CCD camera\/color filter wheel combinations.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSpacing from field flattener to film plane: \u003c\/strong\u003eOptimal spacing from the shoulder of the field flattener (where a T-ring threads on) to a camera's imaging sensor or film plane is 57mm +\/- 4mm. The following DSLR camera body\/T-ring combinations typically all fall within this optimum spacing range and generally should require no additional spacers.\u003c\/p\u003e\n\u003cp\u003eA Canon EOS DSLR\/T-ring combination typically has a T-ring front flange to camera sensor spacing of approximately 55.5mm, although this number is dependent on the thickness of the T-ring you use and cannot be guaranteed. (Without T-ring, the distance from the front flange of the camera body to the sensor is approximately 44mm by itself.)\u003c\/p\u003e\n\u003cp\u003eA Minolta\/Sony DSLR and T-ring combo typically has an approximately 54mm T-ring front flange to sensor spacing. The exact number is again dependent on the thickness of your T-ring. (The camera front flange to sensor distance by itself is approximately 43.5mm.)\u003c\/p\u003e\n\u003cp\u003eA Nikon DSLR and T-ring combo typically has a total spacing of approximately 56mm. This number is again dependent on the T-ring thickness. (The camera front flange to sensor spacing is typically 46.5mm by itself.)\u003c\/p\u003e\n\u003cp\u003eWith CCD and DSI-type cameras, some experimentation with spacers will be necessary to achieve optimum performance, as these typically have much shorter camera front plate to sensor spacing than DSLR cameras.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e8 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":40221666836553,"sku":"AT2FF","price":149.95,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/img_2026.jpg?v=1662967803"},{"product_id":"celestron-0-7x-focal-reducer-for-celestron-11-edgehd-scopes-and-optical-tubes","title":"Celestron 0.7X Focal Reducer For Celestron 11\" EdgeHD Scopes And Optical Tubes","description":"\u003cp\u003eThis Celestron EdgeHD 0.7x focal reducer turns your 11\" f\/10 EdgeHD telescope into a full f-stop faster f\/7 scope, increasing your photographic field of view by 43% and cutting your deep space exposure times in half.\u003c\/p\u003e\n\u003cp\u003eThis Celestron EdgeHD 0.7x focal reducer is a 5-element lens system that converts your 11\" f\/10 EdgeHD scope or optical tube into a fast f\/7 optical system. It threads directly onto the 3.25\" rear cell threads of all 11\" EdgeHD optical tubes, in front of your imaging equipment. It increases your photographic field of view by 43% to better capture wide field images and cuts your deep space exposure times in half, all the while maintaining the flat-field performance of the native Edge HD optical design.\u003c\/p\u003e\n\u003cp\u003eThis Celestron EdgeHD reducer has high index optical elements, including exotic extra low dispersion rare-earth Lanthanum elements, to provide high contrast viewing while minimizing chromatic aberration. All air to glass lens surfaces are fully multicoated for maximum light transmission and color correction. Lens edges are blackened to minimize internal reflection and maximize image contrast. Large diameter lens elements, up to 60 mm clear aperture, ensure that the optimized image circle remains at a generous 42mm for use with large CCD sensors.\u003c\/p\u003e\n\u003cp\u003eThe system maintains the same back focus at its faster f\/7 focal ratio (nominally 146mm from the rear flange of the reducer to the image plane within your camera) as it has when your 11\" scope is used at f\/10. This generous back focus accommodates a wide variety of cameras and imaging accessories.\u003c\/p\u003e\n\u003cp\u003eThreading the CNC machined aluminum housing reducer directly onto the rear cell reduces mechanical vignetting and allows for use with larger (full frame) sensors and off-axis guiders. The CNC machined aluminum housing assures precise spacing and alignment of the optical elements. Threaded metal covers on both sides of the lens assembly protect your investment from dust and scratches. The housing duplicates the rear cell threading of the scope body so you can use of your existing EdgeHD T-adapters with or without the reducer in place.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\" style=\"max-width: 500px;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth style=\"width: 25%;\"\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e49.6 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"width: 25%;\"\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":40481972715593,"sku":"8311HD","price":849.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/19924.jpg?v=1675378878"},{"product_id":"celestron-0-7x-focal-reducer-for-celestron-14-edgehd-scopes-and-optical-tubes","title":"Celestron 0.7X Focal Reducer For Celestron 14\" EdgeHD Scopes And Optical Tubes","description":"\u003cp\u003eThis Celestron EdgeHD 0.7x focal reducer makes your 14\" f\/11 EdgeHD telescope into a full f-stop faster f\/7.7, increasing your photographic field of view by 43% and cutting your deep space exposure times in half .\u003c\/p\u003e\n\u003cp\u003eThis Celestron EdgeHD 0.7x focal reducer is a 5-element lens system that converts your 14\" f\/11 Celestron EdgeHD scope or optical tube into a fast f\/7.7 optical system. It threads directly onto the 3.25\" rear cell threads of all 14\" EdgeHD optical tubes, in front of your imaging equipment. It increases your photographic field of view by 43% to better capture wide field images and cuts your deep space exposure times in half, all the while maintaining the flat-field performance of the native Edge HD optical design.\u003c\/p\u003e\n\u003cp\u003eThis Celestron EdgeHD reducer has high index optical elements, including exotic extra low dispersion rare-earth Lanthanum elements, to provide high contrast viewing while minimizing chromatic aberration. All air to glass lens surfaces are fully multicoated for maximum light transmission and color correction. Lens edges are blackened to minimize internal reflection and maximize image contrast. Large diameter lens elements, up to 60 mm clear aperture, ensure that the optimized image circle remains at a generous 42mm for use with large CCD sensors.\u003c\/p\u003e\n\u003cp\u003eThe system maintains the same back focus at its faster f\/7.7 focal ratio (nominally 146mm from the rear flange of the reducer to the image plane within your camera) as it has when your 14\" scope is used at f\/11. This generous back focus accommodates a wide variety of cameras and imaging accessories.\u003c\/p\u003e\n\u003cp\u003eThreading the CNC machined aluminum housing reducer directly onto the rear cell reduces mechanical vignetting and allows for use with larger (full frame) sensors and off-axis guiders. The CNC machined aluminum housing assures precise spacing and alignment of the optical elements. Threaded metal covers on both sides of the lens assembly protect your investment from dust and scratches. The housing duplicates the rear cell threading of the scope body so you can use of your existing EdgeHD T-adapters with or without the reducer in place.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\" style=\"max-width: 500px;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth style=\"width: 25%;\"\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e49.6 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"width: 25%;\"\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":40481972748361,"sku":"8314HD","price":849.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/19925.jpg?v=1675378880"},{"product_id":"astro-tech-0-8x-reducer-field-flattener-for-f-6-refractors","title":"Astro-Tech 0.8X Reducer\/Field Flattener For f\/6 Refractors","description":"This economical Astro-Tech 2\" 0.8x reducer\/field flattener is designed for astrophotography with f\/6 focal ratio refractors, but will also work well with refractors in the f\/5.5 to f\/7 range . . . \u003cbr\u003e\n\u003cp\u003eNew for August 2021, thread on adapter tops to choose between 42mm T-threads and 48mm T-threads.\u003c\/p\u003e\n\u003cp\u003eWhile this Astro-Tech #ATR8 0.8X reducer\/field flattener is designed for prime focus astrophotography with quality f\/6 focal ratio apo refractors such as the Astro-Tech AT72ED and AT130 apo, it will also work well with Astro-Tech and other brand refractors in the f\/5.5 to f\/7 range that use a 2\" focuser.\u003cbr\u003e\u003cbr\u003eFor example, the fully-multicoated Astro-Tech ATR8 converts the 430mm focal length f\/6 Astro-Tech AT72ED refractor into a 344mm f\/4.8 lens for faster and wider field astronomical and terrestrial photography, while the 777mm f\/7 Astro-Tech AT111EDT converts into a 622mm f\/5.6. \u003cbr\u003e\u003cbr\u003eIn addition to reducing the focal length of the telescope and thereby increasing the photographic speed, the ATR8 flattens the normal field curvature inherent in all refractors to provide images that are sharply focused out to the very corners of a large format DSLR chip. Stars look sharp and point-like all the way across the field in your images. You don't have to worry about photos that are sharp in the center and blurry at the edges.\u003cbr\u003e\u003cbr\u003eThe Astro-Tech ATR8 reducer\/flattener fits 2\" focusers. The 2\" telescope-side barrel is threaded for standard 2\" filters and has a beveled safety groove. The camera side of the reducer has an adapter choice beteen 42mm T-threads, or 48mm T-threads, to connect to a T-ring and camera body. A thread-on metal cover protects the T-threads when the reducer is not in use, while a slip-on dust cover is provided for the 2\" scope-side barrel. Back focus is 55mm from the shoulder of the reducer to the image plane, the standard spacing for 35mm and DSLR camera bodies. The image circle at the focal plane is 42mm in diameter. \u003cbr\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable style=\"max-width: 500px;\" id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth style=\"width: 25%;\"\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5.6 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"width: 25%;\"\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":40481973370953,"sku":"ATR8","price":149.95,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/20002.jpg?v=1675378924"},{"product_id":"celestron-0-7x-focal-reducer-for-celestron-8-edgehd-scopes-and-optical-tubes","title":"Celestron 0.7X Focal Reducer For Celestron 8\" EdgeHD Scopes And Optical Tubes","description":"\u003cp\u003eThis Celestron EdgeHD 0.7x focal reducer turns your 8\" f\/10 EdgeHD telescope into a full f-stop faster f\/7 scope, increasing your photographic field of view by 43% and cutting your deep space exposure times in half . \u003c\/p\u003e\n\u003cdiv\u003eThis Celestron EdgeHD 0.7x focal reducer is a 4-element lens system that converts your 8\" f\/10 EdgeHD scope or optical tube into a fast f\/7 (1422mm focal length) optical system.  \u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003eThe Celestron reducer increases your photographic field of view by 43% to better capture wide field images and cuts your deep space exposure times in half, all the while maintaining the flat-field performance of the EdgeHD's native optical design. It provides an intermediate focal ratio between the 8\" EdgeHD's native f\/10 and the f\/2 ratio that is available with an optional Hyperstar accessory, making the EdgeHD the most complete imaging system in its price range.\u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003eThe 8\" EdgeHD reducer is optimized for use with APS-C size CCD sensors, which are found in most DSLR cameras and in the Celestron Nightscape CCD cameras.\u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003eThe EdgeHD focal reducer uses high index optical elements, including exotic extra low dispersion rare-earth Lanthanum elements, to provide high contrast imaging while minimizing chromatic aberration. All air to glass lens surfaces are fully multicoated for maximum light transmission and color correction. Lens edges are blackened to minimize internal reflection and maximize image contrast. \u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003eThe 8\" EdgeHD reducer threads directly onto the rear cell of all 8\" EdgeHD optical tubes, in place of the scope's visual back. The reducer shortens the 8HD's photographic back focus from 133mm to 105mm (measured from the reducer to the image plane). Used with an optional #93644 8\" EdgeHD T-adapter (with its extension tube removed) it is optimally matched to DSLRs, Celestron Nightscape CCDs, or any other camera with the standard 55mm back focus, with no other focal extension rings or accessories needed. The 105mm back focus allows its use with some off-axis guiders, such as the Celestron #OAG93648, but some additional accessories and\/or spacers may be required. \u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003eThreading the CNC machined aluminum housing of the reducer directly onto the rear cell reduces mechanical vignetting and maximizes imaging train rigidity. The CNC machined aluminum housing assures precise spacing and alignment of the optical elements. Threaded metal covers on both sides of the lens assembly protect your investment from dust and scratches.\u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\" style=\"max-width: 500px;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth style=\"width: 25%;\"\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e0.8 lbs.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"width: 25%;\"\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":40481975533641,"sku":"8308HD","price":419.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/20133.jpg?v=1675379037"},{"product_id":"astro-tech-0-8x-reducer-field-flattener-for-astro-tech-at80edt-triplet-apo-refractor","title":"Astro-Tech 0.8X Reducer\/Field Flattener For Astro-Tech AT80EDT Triplet APO Refractor","description":"\u003cp\u003eThis economical 0.8x focal reducer and field flattener is designed specifically for astrophotography with the Astro-Tech AT80EDT 80mm f\/6 triplet apo refractor.\u003c\/p\u003e\n\u003cdiv\u003eThis Astro-Tech #ATREDT8 0.8X focal reducer\/field flattener is designed specifically for prime focus astrophotography with the Astro-Tech AT80EDT ED triplet apo. While it may also work well with other brands and models of f\/6 refractors that use a 2\" focuser, its performance with other scopes is not guaranteed.\u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003eThe fully-multicoated Astro-Tech #ATREDT8 reducer\/flattener converts the 480mm focal length f\/6 Astro-Tech AT80EDT refractor into a 384mm f\/4.8 system for faster and wider field astronomical and terrestrial photography. \u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003eIn addition to reducing the focal length of the telescope and thereby increasing the photographic speed, the #ATREDT8 flattens the normal field curvature inherent in all refractors. This provides images that are sharply focused out to the corners of DSLR and CCD imaging chips. Stars look sharp and point-like all the way across the field in your images. You don't have to worry about photos that are sharp in the center and blurry at the edges.\u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003eThe Astro-Tech #ATREDT8 reducer\/flattener can be connected to your AT80EDT in two different ways. The first is the most secure for extended imaging sessions. The 2\" barrel of the reducer is threaded at the top, as can be seen in the feature image above. If the 2\" accessory adapter is unthreaded from the camera angle adjuster on the scope, the reducer can be threaded onto the camera angle adjuster in its place for the most solid and secure connection.\u003c\/div\u003e\n\u003cdiv\u003e \u003c\/div\u003e\n\u003cdiv\u003eIn the second connection method, for casual imaging, the 2\" barrel of the #ATREDT8 can simply be slipped into the scope's 2\" focuser in place of your star diagonal. The 2\" telescope-side barrel of the reducer is threaded for standard 2\" filters and has a safety groove. \u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003eThe camera side of the #ATREDT8 reducer has 48mm T-threads to connect to a T-ring and DSLR camera body. A slip-on soft rubber cover protects the T-threads when the reducer is not in use, while a second slip-on cover is provided for the 2\" scope-side barrel. Back focus is 55mm from the shoulder of the reducer to the image plane, the standard spacing for DSLR camera bodies. \u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003eThis model will not work the black focuser body model AT80EDT.\u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\" style=\"max-width: 500px;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth style=\"width: 25%;\"\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e9.5 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"width: 25%;\"\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv\u003e\u003cbr\u003e\u003c\/div\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":40481979301961,"sku":"ATREDT8","price":199.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/astronomics_optimized-0057.jpg?v=1675379279"},{"product_id":"astro-tech-at60ed-field-flattener","title":"Astro-Tech AT60ED Field Flattener","description":"\u003cp\u003eThis thread on field flattener for the AT60ED is a must for full frame photography.The Astro-Tech 60ED 1x flattener easily threads on to the focuser of your AT60ED after your remove the standard compression ring eyepiece holder. The flattener produces wonderful flat fields as well as a 41mm image circle.\u003c\/p\u003e\n\u003cp\u003eThe threads on the t-ring side of the flattener are 48mm male. Make sure your t-ring will work with this particular flattener. The standard for years has been 42mm and not 48mm, so please double check your equipment.\u003c\/p\u003e\n\u003cp\u003eBackfocus from the rear shoulder of the AT60FF to the image plane is 54.8mm, so you may require some additional spacers to reach focus.\u003c\/p\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":40481982873673,"sku":"AT60FF","price":119.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/img_5841.jpg?v=1675379503"},{"product_id":"explore-scientific-3-field-flattener-7x-focal-reducer","title":"Explore Scientific 3\" Field Flattener .7x Focal Reducer","description":"\u003cp\u003e\u003cspan\u003eExplore Scientific’s 3” Field Flattener .7x Focal Reducer is a multi-faceted accessory designed to enhance your astrophotography experiences.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eThe Explore Scientific 3\" Field Flattener\/.7x Focal Reducer is designed to increase your photographic enjoyment of your Explore Scientific refractor.  Depending on which refractor you own, you might need an additional adapter.  Out of the box you will be able to attach it to the 3\" Explore Scientific focuser.  However, you will need the #510366 adapter if you have the 2.5\" Hex focuser, or the 510364 adapter if you have the 2\" Explore Scientific focuser, to attach this piece of equipment to your scope.  \u003c\/p\u003e\n\u003cp\u003eOnce installed you should notice a few things.  1.  The stars are pinpoint out to the edge of your camera, no more curvature.  2. You will notice more sky in your field as you have reduced your f\/ratio by .7x.  And finally 3.  Your exposure times will  have decreased and your images will be brighter due to the faster optic.  \u003c\/p\u003e\n\u003cp\u003eExplore Scientific has thought of everything.  The device is fully multi-coated to help maximize light transmission, and it also comes standard with adapters to help your camera\/DSLR\/CCD attach.\u003c\/p\u003e\n\u003cp\u003eThis piece really works well from f\/8 to f\/7.5.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1 year, extendable to lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":40481983594569,"sku":"ES3FF","price":399.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/f1_1493x_a6f9b499-81ca-4bfe-9c41-784353fe5654.jpg?v=1675379560"},{"product_id":"explore-scientific-adapter-for-3-field-flattener-7x-reducer-to-attach-to-2-5-hex-focuser","title":"Explore Scientific Adapter For 3\" Field Flattener .7x Reducer To Attach To 2.5\" Hex Focuser","description":"\u003cp\u003e \u003c\/p\u003e\n\u003ch3 data-end=\"414\" data-start=\"316\"\u003eExplore Scientific Adapter for 3\" Field Flattener \/ 0.7x Reducer to Attach to 2.5\" Hex Focuser\u003c\/h3\u003e\n\u003cp data-end=\"810\" data-start=\"416\"\u003eIf you're using the Explore Scientific 2.5\" Hex Focuser and looking to expand your astrophotography capabilities, this dedicated adapter lets you seamlessly integrate the Explore Scientific 3\" Field Flattener \/ 0.7x Reducer with your imaging setup. It’s a simple yet critical upgrade for achieving pinpoint stars across a wider field and reducing your effective focal length for faster imaging.\u003c\/p\u003e\n\u003ch4 data-end=\"856\" data-start=\"812\"\u003ePrecision Fit and Optical Compatibility\u003c\/h4\u003e\n\u003cp data-end=\"1202\" data-start=\"858\"\u003eDesigned specifically by Explore Scientific, this adapter ensures a secure mechanical connection between your 2.5\" Hexagonal focuser and the larger 3\" flattener\/reducer assembly. This is not a generic part — it's engineered for precise alignment and rigidity to maintain the critical backfocus and optical path required for optimal performance.\u003c\/p\u003e\n\u003cp data-end=\"1468\" data-start=\"1204\"\u003eThe adapter threads directly onto the rear of the 2.5\" Hex Focuser, replacing the standard 2\" or 2.5\" visual back. On the flattener\/reducer side, it accepts the 3\" component with an exact fit, ensuring no tilt, flex, or misalignment that could degrade your images.\u003c\/p\u003e\n\u003ch4 data-end=\"1504\" data-start=\"1470\"\u003eDesigned for Astrophotography\u003c\/h4\u003e\n\u003cp data-end=\"1892\" data-start=\"1506\"\u003eThis adapter exists purely for imagers. When combined with the 3\" Field Flattener \/ 0.7x Reducer, you'll get a flatter, wider field with reduced vignetting, making it perfect for full-frame and APS-C sensors. The reducer drops your focal ratio by 30%, allowing for shorter exposures and improved performance with faint targets — ideal for nebulae, wide star fields, and larger galaxies.\u003c\/p\u003e\n\u003cp data-end=\"2125\" data-start=\"1894\"\u003eWhether you're using an Explore Scientific ED102, ED127, or other compatible refractor with a 2.5\" Hex Focuser, this adapter makes it possible to expand your system with the more robust 3\" optics designed for larger-format imaging.\u003c\/p\u003e\n\u003ch4 data-end=\"2145\" data-start=\"2127\"\u003eBuilt to Last\u003c\/h4\u003e\n\u003cp data-end=\"2438\" data-start=\"2147\"\u003eMachined from high-quality aluminum with a black anodized finish, this adapter is both durable and lightweight. The internal surfaces are matte black to reduce stray reflections and maintain image contrast. Threading is clean and precise, providing a solid mechanical lock with minimal play.\u003c\/p\u003e\n\u003ch4 data-end=\"2464\" data-start=\"2440\"\u003eNo Tools, No Hassle\u003c\/h4\u003e\n\u003cp data-end=\"2773\" data-start=\"2466\"\u003eInstallation is straightforward. Simply unthread the existing rear accessory collar from your 2.5\" Hex Focuser, thread on the adapter, and then connect your 3\" reducer\/flattener. Once everything is locked into place, you're ready to attach your imaging train and begin capturing sharper, wider-field images.\u003c\/p\u003e\n\u003ch4 data-end=\"2793\" data-start=\"2775\"\u003eKey Features:\u003c\/h4\u003e\n\u003cul data-end=\"3180\" data-start=\"2795\"\u003e\n\u003cli data-end=\"2892\" data-start=\"2795\"\u003eAllows attachment of Explore Scientific 3\" Field Flattener \/ 0.7x Reducer to 2.5\" Hex Focuser\u003c\/li\u003e\n\u003cli data-end=\"2942\" data-start=\"2893\"\u003eCustom-threaded for perfect fit and alignment\u003c\/li\u003e\n\u003cli data-end=\"2997\" data-start=\"2943\"\u003eMaintains critical backfocus and optical integrity\u003c\/li\u003e\n\u003cli data-end=\"3047\" data-start=\"2998\"\u003eIdeal for full-frame and APS-C sensor cameras\u003c\/li\u003e\n\u003cli data-end=\"3119\" data-start=\"3048\"\u003eMachined aluminum construction with anti-reflective interior finish\u003c\/li\u003e\n\u003cli data-end=\"3180\" data-start=\"3120\"\u003eSimple installation — no modifications or tools required\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4 data-end=\"3197\" data-start=\"3182\"\u003eIn Summary\u003c\/h4\u003e\n\u003cp data-end=\"3521\" data-start=\"3199\"\u003eIf you're serious about wide-field astrophotography and want to take full advantage of your Explore Scientific optics, this adapter is an essential piece of the puzzle. It bridges the gap between your high-precision focuser and the power of the 3\" reducer\/flattener system, unlocking better image quality across the board.\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"font-family: -apple-system, BlinkMacSystemFont, 'San Francisco', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif; font-size: 0.875rem;\"\u003eTech Details: \u003c\/span\u003e\u003c\/p\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1 year, extendable to lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":40481983660105,"sku":"510366","price":89.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/es_0510366_1_1493x_106f2c37-8542-462b-a913-b1267ce664bf.jpg?v=1675379566"},{"product_id":"astro-tech-152mm-edt-72x-reducer-field-flattener","title":"Astro-Tech AT152EDT .8X Reducer Field Flattener","description":"\u003cp\u003eThe Astro-Tech AT152FF 0.8x focal reducer\/field flattener is designed specifically for prime focus astrophotography with the AT152EDT triplet refractor.\u003c\/p\u003e\n\u003cp\u003eThe fully-multicoated reducer\/flattener converts the 1216mm fl 152EDT into an 973mm f\/6.4 photographic system.\u003c\/p\u003e\n\u003cp\u003eNot only do you get to speed up your scope, it will also flatten the normal field curvature inherent in all refractors.\u003c\/p\u003e\n\u003cp\u003eInstallation is simple. Just unthread the 2\" adapter from the focuser drawtube. This will expose the 92mm threads. Now, just thread the AT152FF in its place and you are ready to go.\u003c\/p\u003e\n\u003cp\u003eThe camera side of the reducer has 48mm t-threads, so make sure your t-ring will work.\u003c\/p\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":40481985069129,"sku":"AT152FF","price":299.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/at152ffbw.jpg?v=1675379657"},{"product_id":"sky-watcher-0-85x-focal-reducer-corrector-for-pro-ed80-telescope","title":"Sky-Watcher 0.85x Focal Reducer\/Corrector For Pro 80 ED APO Telescope S20200","description":".85x Reduction For Your Sky-Watcher Pro 80 ED APO Refractor Helps Correct Distortion Out to the Edge of the Field Requires a 48mm T-Ring\n\u003cp\u003eSo you want to take the nest step up in your photography with your Sky-Watcher 80mm ED refractor.  This Sky-Watcher .85x Focal Reducer\/Corrector will get you on your way.  The Sky-Watcher S20200 will reduce the focal length by 0.85x effectively widening your photographic field.  However, it will also correct at the edges of the field helping to flatten out the field.\u003c\/p\u003e\n\u003cp\u003eThis reducer requires a 48mm T-Ring.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e.7 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":40481985396809,"sku":"S20200","price":370.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/s20200.jpg?v=1675379676"},{"product_id":"sky-watcher-0-85x-focal-reducer-corrector-for-pro-100-ed-apo-telescope","title":"Sky-Watcher 0.85x Focal Reducer \/ Corrector For Pro 100 ED APO Telescope S20201","description":".85x Reduction For Your Sky-Watcher Pro 100 ED APO Refractor Helps Correct Distortion Out to the Edge of the Field Requires a 48mm T-Ring\n\u003cp\u003eSo you want to take the nest step up in your photography with your Sky-Watcher 100mm ED refractor.  This Sky-Watcher .85x Focal Reducer\/Corrector will get you on your way.  The Sky-Watcher S20201 will reduce the focal length by 0.85x effectively widening your photographic field.  However, it will also correct at the edges of the field helping to flatten out the field.\u003c\/p\u003e\n\u003cp\u003eThis reducer requires a 48mm T-Ring.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e.7 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":40481985429577,"sku":"S20201","price":380.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/s20201_reducercorrecto_large_5d3fada5-dc64-415a-86dd-a1e2d3fcc284.jpg?v=1675379678"},{"product_id":"sky-watcher-0-85x-focal-reducer-corrector-for-pro-120-ed-apo-telescope","title":"Sky-Watcher 0.85x Focal Reducer\/Corrector For Pro 120 ED APO Telescope S20202","description":".85x Reduction For Your Sky-Watcher Pro 120 ED APO Refractor and 150ED Refractor. Helps Correct Distortion Out to the Edge of the Field Requires a 48mm T-Ring\n\u003cp\u003eSo you want to take the nest step up in your photography with your Sky-Watcher 120mm ED or 150mm ED refractor.  This Sky-Watcher .85x Focal Reducer\/Corrector will get you on your way.  The Sky-Watcher S20202 will reduce the focal length by 0.85x effectively widening your photographic field.  However, it will also correct at the edges of the field helping to flatten out the field.\u003c\/p\u003e\n\u003cp\u003eThis reducer requires a 48mm T-Ring.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e.7 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":40481985495113,"sku":"S20202","price":395.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/s20202_reducercorrecto_large_c79bafc5-d7a5-4523-a4f7-03ad0885c7d6.jpg?v=1675379680"},{"product_id":"celestron-7x-reducer-lens-for-the-edgehd-925","title":"Celestron .7X Reducer Lens For The EdgeHD 925","description":"\u003cp\u003eThe EdgeHD .7x Focal Reducer Lens makes your EdgeHD 9.25\" one full F-Stop faster than f\/10, reducing your exposure time by half to capture the same brightness of object 4-element lens design\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eMaintains similar flat-field performance as native EdgeHD optical design\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eIncreases field of view by 43% to better capture wide field images\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eThreads directly onto the 3.25\" threads of the EdgeHD which reduces mechanical vignetting and allows for use with larger (full frame) sensors and Off-Axis Guiders\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eMaintains the identical back focus when used at f\/10 and provides generous back focus to accommodate additional accessories and wide variety of cameras\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eAllows use of existing EdgeHD T-Adapters with or without the Reducer Lens\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eCelestron’s new EdgeHD reducers feature a custom 4-element optical design engineered to maintain the flat-field performance of our award winning EdgeHD optical system. Unlike generic reducers, our premium reducers provide substantial back focus to accommodate an assortment of imaging accessories.\u003c\/p\u003e\n\u003cp\u003eEdgeHD reducers offer high index optical elements, including extra low dispersion, exotic Lanthanum elements, which provide high contrast viewing while minimizing chromatic aberration. All air to glass lens surfaces feature multiple layers of coating for maximum light transmission and color correction and contain blacken edges to minimize internal reflection and maximize image contrast. Large diameter lens elements, up to 60 mm clear aperture, ensure that the optimized image circle remains at a generous 42 mm for use with large CCD sensors.\u003c\/p\u003e\n\u003cp\u003eIncorporating computer assisted CNC machined aluminum housing, for precise spacing and alignment of optical elements, and threaded metal covers on the lens assembly to protect your investment from dust and scratches, our reducers offer you an outstanding mechanical design.\u003c\/p\u003e\n\u003cp\u003eWith the fastar option on all EdgeHD optical systems, coupled with the .7x reducer, your telescope becomes the most complete imaging system available in its price range today.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePerformance\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDesign:\u003c\/strong\u003e 4-element optical layout designed specifically for the EdgeHD 9.25\" to maintain the flat-field performance of the EdgeHD optical design\u003cbr\u003e\u003cstrong\u003eMaintains the same back focus as when used at f\/10:\u003c\/strong\u003e Unlike generic reducers the EdgeHD .7x provides generous back focus to accommodate additional accessories and a wide variety of cameras. Also allows use of existing EdgeHD T-Adapters and other Celestron imaging accessories\u003cbr\u003e\u003cstrong\u003eOne full F-Stop faster than f\/10:\u003c\/strong\u003e Reduces the exposure time by one-half to capture the same brightness of object\u003cbr\u003e\u003cstrong\u003eIncrease field of view by 43%:\u003c\/strong\u003e Better for capturing wide field images of larger galaxies and nebulae\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGlass\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eLanthanum Glass Elements:\u003c\/strong\u003e EdgeHD reducer uses \"rare earth\" Lanthanum glass elements for clear, high contrast viewing while minimizing chromatic aberration\u003cbr\u003e\u003cstrong\u003eFully multi-coated lens elements:\u003c\/strong\u003e All air-to-glass surfaces have multiple layers of coating for maximum light transmission and color correction\u003cbr\u003e\u003cstrong\u003eBlacken edges:\u003c\/strong\u003e All lens elements have blacken edges to minimize internal reflection and maximize contras\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFull Frame Design\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThreads directly onto the 3.25\" threads of the EdgeHD optical tube:\u003c\/strong\u003e Reduces mechanical vignetting and allows for use with larger (full frame) sensors and Off-Axis Guiders\u003cbr\u003e\u003cstrong\u003eClear aperture:\u003c\/strong\u003e 60 mm clear aperture lens optimized for a 42 mm image circle for use with large CCD sensors.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMechanical Design\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMachined aluminum housing:\u003c\/strong\u003e Computer assisted CNC machined aluminum housing for precise spacing and alignment of the optical elements.\u003cbr\u003e\u003cstrong\u003eThreaded metal covers for both ends of the lens assembly:\u003c\/strong\u003e To protect your investment from unwanted dust and scratches.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eVersatility\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFastar compatibility and f\/2 imaging with optional accessory:\u003c\/strong\u003e the EdgeHD is the most complete imaging system in its price range.\u003c\/p\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":40481987002441,"sku":"94245","price":439.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/94245_reducer_lens_edgehd_9.25_1_570x380_2x_7ccbfea6-bc0a-409f-b8eb-6d895b152f52.jpg?v=1675379772"},{"product_id":"astro-tech-8x-reducer-field-flattener-for-the-60ed-and-72ed-optical-tubes","title":"Astro-Tech .8X Reducer Field Flattener For The 72EDII Optical Tubes","description":"Looking to make your Astro-Tech (or variant) scope faster and flatter for photography?  Then the .8x reducer\/flattener is exactly what your are looking for.\u003cp\u003eWhile this Astro-Tech ATRF72 0.8X reducer\/field flattener is designed for prime focus astrophotography with the Astro-Tech  AT72EDII, it will work with other variants of the same optical tube. Feel free to give us a call if you have a question about your scope if it isn’t an Astro-Tech product. 800-422-7876\u003c\/p\u003e\n\u003cp\u003eThe fully-multicoated Astro-Tech ATRF72 converts the 430mm focal length f\/6 Astro-Tech AT72ED refractor into a 344mm f\/4.8 lens for faster and wider field astronomical and terrestrial photography.\u003c\/p\u003e\n\u003cp\u003eIn addition to reducing the focal length of the telescope and thereby increasing the photographic speed, the ATRF72 flattens the normal field curvature inherent in all refractors to provide images that are sharply focused out to the very corners of a large format DSLR chip. Stars look sharp and point-like all the way across the field in your images. You don't have to worry about photos that are sharp in the center and blurry at the edges.\u003c\/p\u003e\n\u003cp\u003eThe Astro-Tech ATRF72 reducer\/flattener threads on the 72EDII focusers. The flattener is threaded for attachment to the telescope via a 54mm metric thread. The camera side of the reducer has 48mm T-threads to connect to a T-ring and camera body. Back focus is 55mm from the shoulder of the reducer to the image plane, the standard spacing for 35mm and DSLR camera bodies.\u003c\/p\u003e\n\u003cp\u003eThe interior of the telescope side of the reducer\/field flattener is a 48mm female thread so standard 2\" filters can thread right in.\u003c\/p\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":40481989001289,"sku":"ATRF72","price":159.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/Astronomics-Astronomy-Store-telescopes-78.png?v=1714677676"},{"product_id":"astro-tech-8x-reducer-field-flattener-for-the-60ed-optical-tubes","title":"Astro-Tech .8X Reducer Field Flattener For The 60ED Optical Tubes","description":"Looking to make your Astro-Tech (or variant) scope faster and flatter for photography?  Then the .8x reducer\/flattener is exactly what your are looking for.\u003cp\u003eWhile this Astro-Tech ATRF60 0.8X reducer\/field flattener is designed for prime focus astrophotography with the Astro-Tech  AT60ED, it will work with other variants of the same optical tube. Feel free to give us a call if you have a question about your scope if it isn’t an Astro-Tech product. 800-422-7876\u003c\/p\u003e\r\n\u003cp\u003eThe fully-multicoated Astro-Tech ATRF60 converts the 360mm focal length f\/6 Astro-Tech AT60ED refractor into a 288mm f\/4.8 lens for faster and wider field astronomical and terrestrial photography.\u003c\/p\u003e\r\n\u003cp\u003eIn addition to reducing the focal length of the telescope and thereby increasing the photographic speed, the ATRF60 flattens the normal field curvature inherent in all refractors to provide images that are sharply focused out to the very corners of a large format DSLR chip. Stars look sharp and point-like all the way across the field in your images. You don't have to worry about photos that are sharp in the center and blurry at the edges.\u003c\/p\u003e\r\n\u003cp\u003eThe Astro-Tech ATRF60 reducer\/flattener threads on the 60ED focusers. The flattener is threaded for attachment to the telescope via a 54mm metric thread. The camera side of the reducer has 48mm T-threads to connect to a T-ring and camera body. Back focus is 55mm from the shoulder of the reducer to the image plane, the standard spacing for 35mm and DSLR camera bodies.\u003c\/p\u003e\r\n\u003cp\u003eThe interior of the telescope side of the reducer\/field flattener is a 48mm female thread so standard 2\" filters can thread right in.\u003c\/p\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":40481989034057,"sku":"ATRF60","price":159.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/Astronomics-Astronomy-Store-telescopes-87.png?v=1714677601"},{"product_id":"astro-tech-0-8x-reducer-field-flattener-for-astro-tech-at115edt-triplet-apo-refractor","title":"Astro-Tech 0.8X Reducer\/Field Flattener For Astro-Tech AT115EDT Triplet APO Refractor Version II","description":"\u003cp\u003eYou've got 115mm of ED triplet glass pointed at the sky. The AT115EDT's optics deliver clean color correction — three FK-61 elements working together the way they should. But point a camera at the focal plane and the triplet shows you what it doesn't correct natively: field curvature. Center stars are tight and round. Corner stars are not. They stretch, they soften, they remind you that a refractor designed for visual use doesn't automatically produce flat-field images. The ATREDT15V2 fixes that. It flattens the field and reduces the focal length at the same time — converting 805mm f\/7 into 644mm f\/5.6 with sharp, corrected stars across your sensor.\u003c\/p\u003e\n\u003cp\u003eThat focal reduction matters more than the number suggests. At f\/5.6, your exposures run approximately 36% shorter than at f\/7 for the same signal. On a narrowband target at 5-minute subs, that's real time saved — or, looked at another way, significantly more signal per frame. The wider field of view means objects that were tight fits at 805mm now have room to breathe. The Rosette Nebula, the Orion Nebula, the Veil Nebula — they all frame more comfortably at 644mm than they do at native focal length.\u003c\/p\u003e\n\u003cp\u003eThe ATREDT15V2 threads into the focuser drawtube or camera angle adjuster of the AT115EDT via M63×1 threads. This is a secure, rigid connection — no barrel slip, no adapter stack flexing under your camera's weight. The camera side uses standard 48mm T-threads, connecting to a T-ring for DSLR and mirrorless bodies, or directly to dedicated CMOS and CCD astronomy cameras, which come with 48mm T-threads built in. Back focus is 55mm from the reducer shoulder to the image plane, which is the standard spacing for most DSLR T-ring combinations and dedicated camera setups.\u003c\/p\u003e\n\u003cp\u003eFully multi-coated with broadband anti-reflection coatings on all optical surfaces. Slip-on rubber dust covers are included for both ends — scope side and camera side — to protect the coated glass between imaging sessions.\u003c\/p\u003e\n\u003ch3\u003eImportant: Which Reducer for Which Focuser\u003c\/h3\u003e\n\u003cp\u003eThe AT115EDT has been produced with different focuser versions over its production run. This reducer — the ATREDT15V2 — is designed for the 2.5-inch focuser with M63×1 drawtube threads. If your AT115EDT has the newer 3.2-inch focuser with M92 drawtube threads, you would want to consider the AT115EDTRFv3 instead. However, this model will work the the 3.2\" focuser, it just won't produce as large an image circle. \u003c\/p\u003e\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eAstro-Tech ATREDT15V2 0.8× reducer\/field flattener\u003c\/li\u003e\n\u003cli\u003eSlip-on rubber dust cover (scope side)\u003c\/li\u003e\n\u003cli\u003eSlip-on rubber dust cover (camera side)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e0.8× focal reduction\u003c\/strong\u003e — Converts the AT115EDT from 805mm f\/7 to 644mm f\/5.6. Approximately 36% shorter exposures for the same signal, and a meaningfully wider field of view for framing large deep-sky objects.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eField flattener integrated\u003c\/strong\u003e — Corrects the native field curvature of the AT115EDT triplet. Stars stay sharp and round from center to corner across your imaging sensor. No separate flattener needed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM63×1 scope-side connection\u003c\/strong\u003e — Threads directly into the AT115EDT's 2.5-inch focuser drawtube or camera angle adjuster. Rigid, secure, no barrel slip or flexure under camera weight.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48mm T-threads on camera side\u003c\/strong\u003e — DSLR and mirrorless bodies connect via a T-ring for your specific mount (sold separately). Dedicated CMOS and CCD astronomy cameras attach directly — 48mm T-threads are standard on most.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e55mm back focus\u003c\/strong\u003e — Standard spacing from reducer shoulder to image plane. Most DSLR T-ring combinations and dedicated camera setups reach this distance naturally. If your setup differs, shim with T-thread spacers to hit 55mm precisely.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully multi-coated optics\u003c\/strong\u003e — Broadband anti-reflection coatings on all surfaces. Contrast is preserved and internal reflections are controlled — important for narrowband work where stray light shows up fast.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDust covers included\u003c\/strong\u003e — Slip-on rubber covers for both ends. Protect the coated surfaces when the reducer isn't on the scope.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompact, lightweight\u003c\/strong\u003e — Adds minimal weight and length to your imaging train. The AT115EDT's balance point barely shifts.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eObserving Tip\u003c\/h3\u003e\n\u003cp\u003eGetting the back focus right is the single most important thing you can do with this reducer. At 55mm, the field correction is optimized — sharp stars to the corners. Too short or too long, and you'll see elongated stars at the edges that no amount of post-processing will fix. Measure from the reducer's shoulder (the flat face where it meets the T-ring or camera adapter) to your sensor. A set of T-thread spacers (AT4220 and AT4230) lets you dial in the exact distance. It's worth spending ten minutes with a ruler before your first imaging session — the results on screen will tell you immediately whether you got it right.\u003c\/p\u003e\n\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eDo I need a T-ring to connect my camera?\u003c\/strong\u003e\u003cbr\u003eIt depends on your camera. Dedicated CMOS and CCD astronomy cameras (ZWO, QHY, Player One, and similar) typically have 48mm T-threads built in and connect directly to the ATREDT15V2 — no T-ring needed. DSLR and mirrorless cameras (Canon, Nikon, Sony, and others) connect via a T-ring for your specific lens mount. The T-ring is sold separately.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use filters with this reducer?\u003c\/strong\u003e\u003cbr\u003eThe ATREDT15V2 does have an internal filter threads like the V3 version. Just unthread the knurled ring on the top of the reducer to expose the fitler threads on the underside of it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat happens if my back focus is off?\u003c\/strong\u003e\u003cbr\u003eYou'll see elongated or distorted stars at the edges of your images — the field correction is optimized for 55mm. Too short and stars stretch one way; too long and they stretch the other. Use T-thread spacers to fine-tune the distance. Measure from the reducer shoulder to your sensor before your first session.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use this with other telescopes?\u003c\/strong\u003e\u003cbr\u003eIt may work with other f\/7 refractors that have a 2.5-inch focuser with M63×1 threads, but we can only confirm performance with the AT115EDT. The optical design is matched to the AT115EDT's focal length and field curvature. Using it with other scopes may produce usable results, but we can't guarantee corner correction.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow does this compare to the 1× field flattener?\u003c\/strong\u003e\u003cbr\u003eThe 1× flattener (AT115EDTFF) corrects field curvature without changing the focal length — you stay at 805mm f\/7. The 0.8× reducer (this product) both flattens the field and shortens the focal length to 644mm f\/5.6. Use the 1× flattener when you want maximum image scale and don't need faster exposures. Use the 0.8× reducer when you want a wider field and shorter exposures. Most AT115EDT imagers end up using the reducer more often.\u003c\/p\u003e\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\u003cp\u003eIf you're imaging with an AT115EDT that has the 2.5-inch focuser, the ATREDT15V2 is the reducer that was designed for it. The optical correction is matched to the AT115EDT's triplet, the M63 threading gives you a rigid connection without adapter stacks, and 644mm at f\/5.6 opens up the wide-field deep-sky targets that are cramped at native focal length. It does two things — flattens the field and speeds up the system — and it does both well. Get the back focus right at 55mm, and the corners of your frames will tell you the rest.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eModel\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eATREDT15V2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCompatible Telescope\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAT115EDT (2.5\" and 3.2\" Grey focusers)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFocal Reduction\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e0.8×\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eResulting Focal Length\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e644mm (from 805mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eResulting Focal Ratio\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003ef\/5.6 (from f\/7)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eScope Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eM63×1 threads (into 2.5\" focuser drawtube or CAA)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCamera Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e48mm T-threads\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBack Focus\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e55mm (reducer shoulder to sensor)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully multi-coated, broadband AR\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eIncluded Accessories\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eSlip-on rubber dust covers (scope side and camera side)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":40481992736841,"sku":"ATREDT15V2","price":229.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/astronomics_optimized-0056.jpg?v=1675380119"},{"product_id":"astro-tech-0-8x-reducer-field-flattener-for-astro-tech-at130edt-triplet-apo-refractor","title":"Astro-Tech 0.8X Reducer\/Field Flattener For Astro-Tech AT130EDT Triplet APO Refractor Version II","description":"\u003cp\u003eYou've got 130mm of ED triplet glass pointed at the sky. The AT130EDT's optics deliver clean color correction — three FK-61 elements working together the way they should. But point a camera at the focal plane and the triplet shows you what it doesn't correct natively: field curvature. Center stars are tight and round. Corner stars are not. They stretch, they soften, they remind you that a refractor designed for visual use doesn't automatically produce flat-field images. The ATREDT30V2 fixes that. It flattens the field and reduces the focal length at the same time — converting 910mm f\/7 into 728mm f\/5.6 with sharp, corrected stars across your sensor.\u003c\/p\u003e\n\u003cp\u003eThat focal reduction matters more than the number suggests. At f\/5.6, your exposures run approximately 36% shorter than at f\/7 for the same signal. On a narrowband target at 5-minute subs, that's real time saved — or, looked at another way, significantly more signal per frame. The wider field of view means objects that were tight fits at 910mm now have room to breathe. The Rosette Nebula, the North America Nebula complex, the California Nebula — they all frame more comfortably at 728mm than they do at native focal length.\u003c\/p\u003e\n\u003cp\u003eThe ATREDT30V2 threads into the focuser drawtube or camera angle adjuster of the AT130EDT via M63×1 threads. This is a secure, rigid connection — no barrel slip, no adapter stack flexing under your camera's weight. The camera side uses standard 48mm T-threads, connecting to a T-ring for DSLR and mirrorless bodies, or directly to dedicated CMOS and CCD astronomy cameras, which come with 48mm T-threads built in. Back focus is 55mm from the reducer shoulder to the image plane, which is the standard spacing for most DSLR T-ring combinations and dedicated camera setups.\u003c\/p\u003e\n\u003cp\u003eFully multi-coated with broadband anti-reflection coatings on all optical surfaces. Slip-on rubber dust covers are included for both ends — scope side and camera side — to protect the coated glass between imaging sessions.\u003c\/p\u003e\n\u003ch3\u003eImportant: Which Reducer for Which Focuser\u003c\/h3\u003e\n\u003cp\u003eThe AT130EDT has been produced with different focuser versions over its production run. This reducer — the ATREDT30V2 — is designed for the 2.5-inch focuser with M63×1 drawtube threads, but it can work with the new 3.2\" focuser. If your AT130EDT has the newer 3.2-inch focuser with M92 drawtube threads, you might want to consider the  AT130EDTRFv3 as it produces a larger image circle.  This reducer will also not work with the original black-bodied focuser model. If you're not sure which focuser you have, check the drawtube diameter or call us.\u003c\/p\u003e\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eAstro-Tech ATREDT30V2 0.8× reducer\/field flattener\u003c\/li\u003e\n\u003cli\u003eSlip-on rubber dust cover (scope side)\u003c\/li\u003e\n\u003cli\u003eSlip-on rubber dust cover (camera side)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e0.8× focal reduction\u003c\/strong\u003e — Converts the AT130EDT from 910mm f\/7 to 728mm f\/5.6. Approximately 36% shorter exposures for the same signal, and a meaningfully wider field of view for framing large deep-sky objects.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eField flattener integrated\u003c\/strong\u003e — Corrects the native field curvature of the AT130EDT triplet. Stars stay sharp and round from center to corner across your imaging sensor. No separate flattener needed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM63×1 scope-side connection\u003c\/strong\u003e — Threads directly into the AT130EDT's 2.5-inch focuser drawtube or camera angle adjuster. Rigid, secure, no barrel slip or flexure under camera weight.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48mm T-threads on camera side\u003c\/strong\u003e — DSLR and mirrorless bodies connect via a T-ring for your specific mount (sold separately). Dedicated CMOS and CCD astronomy cameras attach directly — 48mm T-threads are standard on most.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e55mm back focus\u003c\/strong\u003e — Standard spacing from reducer shoulder to image plane. Most DSLR T-ring combinations and dedicated camera setups reach this distance naturally. If your setup differs, shim with T-thread spacers to hit 55mm precisely.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully multi-coated optics\u003c\/strong\u003e — Broadband anti-reflection coatings on all surfaces. Contrast is preserved and internal reflections are controlled — important for narrowband work where stray light shows up fast.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDust covers included\u003c\/strong\u003e — Slip-on rubber covers for both ends. Protect the coated surfaces when the reducer isn't on the scope.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompact, lightweight\u003c\/strong\u003e — Adds minimal weight and length to your imaging train. The AT130EDT's balance point barely shifts.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eObserving Tip\u003c\/h3\u003e\n\u003cp\u003eGetting the back focus right is the single most important thing you can do with this reducer. At 55mm, the field correction is optimized — sharp stars to the corners. Too short or too long, and you'll see elongated stars at the edges that no amount of post-processing will fix. Measure from the reducer's shoulder (the flat face where it meets the T-ring or camera adapter) to your sensor. A set of T-thread spacers (AT4220 and AT4230) lets you dial in the exact distance. It's worth spending ten minutes with a ruler before your first imaging session — the results on screen will tell you immediately whether you got it right.\u003c\/p\u003e\n\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWill this work on the AT130EDT with the 3.2-inch focuser?\u003c\/strong\u003e\u003cbr\u003eYes. This reducer uses M63×1 threads which you can access on the 3.2\" focuser. \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDo I need a T-ring to connect my camera?\u003c\/strong\u003e\u003cbr\u003eIt depends on your camera. Dedicated CMOS and CCD astronomy cameras (ZWO, QHY, Player One, and similar) typically have 48mm T-threads built in and connect directly to the ATREDT30V2 — no T-ring needed. DSLR and mirrorless cameras (Canon, Nikon, Sony, and others) connect via a T-ring for your specific lens mount. The T-ring is sold separately.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use filters with this reducer?\u003c\/strong\u003e\u003cbr\u003eThe ATREDT30V2 does have the internal filter threads when you thread off the knurled end cap.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat happens if my back focus is off?\u003c\/strong\u003e\u003cbr\u003eYou'll see elongated or distorted stars at the edges of your images — the field correction is optimized for 55mm. Too short and stars stretch one way; too long and they stretch the other. Use T-thread spacers to fine-tune the distance. Measure from the reducer shoulder to your sensor before your first session.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use this with other telescopes?\u003c\/strong\u003e\u003cbr\u003eIt may work with other f\/7 refractors that have a 2.5-inch focuser with M63×1 threads, but we can only confirm performance with the AT130EDT. The optical design is matched to the AT130EDT's focal length and field curvature. Using it with other scopes may produce usable results, but we can't guarantee corner correction.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow does this compare to the 1× field flattener?\u003c\/strong\u003e\u003cbr\u003eThe 1× flattener (AT130EDTFF) corrects field curvature without changing the focal length — you stay at 910mm f\/7. The 0.8× reducer (this product) both flattens the field and shortens the focal length to 728mm f\/5.6. Use the 1× flattener when you want maximum image scale and don't need faster exposures. Use the 0.8× reducer when you want a wider field and shorter exposures. Most AT130EDT imagers end up using the reducer more often.\u003c\/p\u003e\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\u003cp\u003eIf you're imaging with an AT130EDT that has the 2.5-inch focuser, the ATREDT30V2 is the reducer that was designed for it. The optical correction is matched to the AT130EDT's triplet, the M63 threading gives you a rigid connection without adapter stacks, and 728mm at f\/5.6 opens up the wide-field deep-sky targets that are cramped at native focal length. It does two things — flattens the field and speeds up the system — and it does both well. Get the back focus right at 55mm, and the corners of your frames will tell you the rest.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eModel\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eATREDT30V2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCompatible Telescope\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAT130EDT (2.5\" focuser or 3.2\" focuser)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFocal Reduction\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e0.8×\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eResulting Focal Length\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e728mm (from 910mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eResulting Focal Ratio\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003ef\/5.6 (from f\/7)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eScope Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eM63×1 threads (into 2.5\" focuser drawtube or CAA)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCamera Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e48mm T-threads\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBack Focus\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e55mm (reducer shoulder to sensor)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully multi-coated, broadband AR\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eIncluded Accessories\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eSlip-on rubber dust covers (scope side and camera side)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":40481992769609,"sku":"ATREDT30V2","price":229.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/astronomics_optimized-0053.jpg?v=1675380122"},{"product_id":"astro-tech-0-8x-reducer-field-flattener-for-astro-tech-at102edl-doublet-apo-refractor","title":"Astro-Tech 0.8X Reducer\/Field Flattener For Astro-Tech AT102EDL Doublet Apo Refractor","description":"\u003cp\u003eThe AT102EDL is a versatile doublet APO at 714mm f\/7 — plenty of focal length for mid-range targets and sharp enough for visual work on any given night. But when you attach a camera, the field curvature that's invisible at the eyepiece becomes obvious in your images. Stars that are tight in the center soften into small streaks near the corners. The AT102EDLRF corrects that curvature and reduces the focal length to 571mm f\/5.6 — a 56% increase in photographic speed — so you get flat fields, round stars, and shorter exposures in one piece of glass.\u003c\/p\u003e\n\n\u003ch3\u003eDesigned for One Scope\u003c\/h3\u003e\n\n\u003cp\u003eThis reducer\/flattener is computed specifically for the field curvature of the Astro-Tech AT102EDL 102mm f\/7 doublet APO refractor. A generic 0.8x reducer will shorten the focal length, but it won't match the correction to your scope's specific optical profile. This one does. It may thread into other f\/7 refractors with a 2.5-inch focuser, but optical performance outside the AT102EDL is not guaranteed.\u003c\/p\u003e\n\n\u003ch3\u003eHow It Connects\u003c\/h3\u003e\n\n\u003cp\u003eThe scope side threads into the focuser drawtube using M63×1 metric threads — a solid, repeatable connection with no compression ring and no play. The camera side has standard 48mm T-threads, connecting to a T-ring for DSLR and mirrorless bodies, or directly to dedicated CMOS and CCD astronomy cameras, which come with 48mm T-threads built in.\u003c\/p\u003e\n\n\u003cp\u003eBack focus is 55mm from the shoulder of the reducer to the image plane. That's the standard DSLR spacing — a T-ring and camera body will put you at the correct distance without spacers. For dedicated astronomy cameras, measure your camera's back focus specification and add spacers if needed to reach 55mm.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAstro-Tech AT102EDLRF 0.8x reducer\/field flattener\u003c\/li\u003e\n  \u003cli\u003eSlip-on rubber dust cover for 48mm T-threads (camera side)\u003c\/li\u003e\n  \u003cli\u003eSlip-on dust cover for 2\" scope-side barrel\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e0.8x focal reduction\u003c\/strong\u003e — Converts the AT102EDL from 714mm f\/7 to 571mm f\/5.6. That's a 56% increase in photographic speed — the same signal-to-noise ratio in roughly two-thirds the exposure time.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eField flattening\u003c\/strong\u003e — Corrects the native field curvature of the AT102EDL so stars stay round and sharp all the way to the corners of your imaging chip.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFully multi-coated optics\u003c\/strong\u003e — Minimizes reflections and maximizes light transmission through the reducer elements.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eM63×1 scope-side thread\u003c\/strong\u003e — Threads securely into the focuser drawtube. No set screws, no wobble, no shift between sessions.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e48mm T-thread camera connection\u003c\/strong\u003e — DSLR and mirrorless bodies connect via a T-ring (sold separately); dedicated CMOS\/CCD astronomy cameras attach directly — 48mm T-threads are standard on most.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e55mm back focus\u003c\/strong\u003e — Standard DSLR spacing. No spacers needed for most DSLR setups. Dedicated astronomy cameras may require spacers to reach the correct distance.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompact and lightweight\u003c\/strong\u003e — 8 ounces. Adds minimal weight to your imaging train.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eImaging Tip\u003c\/h3\u003e\n\n\u003cp\u003eWhen you first set up the AT102EDLRF, shoot a short test exposure of a star field and inspect the corners at 100% zoom. If stars are elongated radially (pointing away from center), you're too far from the reducer — remove a spacer or check your T-ring stack. If stars are elongated tangentially (perpendicular to the radial direction), you're too close. The 55mm specification is measured from the shoulder of the reducer, not the rear element — make sure you're measuring from the right reference point.\u003c\/p\u003e\n\n\u003ch3\u003eFAQ\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eWill this work with my AT125EDL or AT150EDL?\u003c\/strong\u003e\u003cbr\u003e\nNo. Each EDL scope has its own dedicated reducer matched to its specific field curvature. The AT125EDL uses the AT125EDLRF, and the AT150EDL uses the AT150EDLRF. They are not interchangeable.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCan I use this visually?\u003c\/strong\u003e\u003cbr\u003e\nThe reducer is designed for prime-focus astrophotography. It will not reach focus with an eyepiece and is not intended for visual use.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDo I need a T-ring?\u003c\/strong\u003e\u003cbr\u003e\nDSLR and mirrorless cameras connect via a T-ring for your specific mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have 48mm T-threads built in and connect directly without a T-ring.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat sensors have been tested with this reducer?\u003c\/strong\u003e\u003cbr\u003e\nOwners report sharp stars to the edges of 4\/3-format sensors (like the ASI-294mc) at the specified 55mm back focus. Results on larger APS-C and full-frame sensors will depend on precise spacing — test and adjust before committing to long integration times.\u003c\/p\u003e\n\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\n\u003cp\u003eIf you're imaging through the AT102EDL, this is the reducer that was built for it. It flattens the field, speeds the system to f\/5.6, and threads in with a secure M63 connection that holds position between sessions. At 8 ounces, it barely changes the balance of your imaging train. The AT102EDL is already one of the most capable doublets in its aperture class — the AT102EDLRF turns it into a proper imaging platform with flat fields and faster exposures.\u003c\/p\u003e\n\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable style=\"width:100%; border-collapse: collapse;\"\u003e\u003ctbody\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eReduction Factor\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e0.8x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eDesigned For\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT102EDL 102mm f\/7 Doublet APO Refractor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eNative Focal Length\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e714mm f\/7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eResulting Focal Length\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e571mm f\/5.6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully multi-coated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eScope-Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eM63×1 metric thread (focuser drawtube)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCamera-Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e48mm T-threads\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBack Focus\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e55mm (from shoulder of reducer to image plane)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003ePhotographic Speed Increase\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e56% (f\/7 to f\/5.6)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e8 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eIncluded\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eReducer\/flattener, T-thread dust cover, scope-side dust cover\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":40481994244169,"sku":"AT102EDLRF","price":199.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/0.8XReducer_Flattener_1-10522.jpg?v=1714680170"},{"product_id":"astro-tech-0-8x-reducer-field-flattener-for-astro-tech-at125edl-doublet-apo-refractor","title":"Astro-Tech 0.8X Reducer\/Field Flattener For Astro-Tech AT125EDL Doublet APO Refractor","description":"\u003cp\u003eThe AT125EDL is a serious visual scope at 975mm f\/7.8, but when you turn it toward astrophotography, two things work against you: the curved field stretches stars into small comets near the corners of your sensor, and the slow focal ratio means longer exposures to capture the same depth of signal. The AT125EDLRF fixes both. It reduces the focal length to 780mm, speeding the system to f\/6.2 — a 56% increase in photographic speed — and flattens the field so stars stay round and tight from center to edge.\u003c\/p\u003e\n\n\u003ch3\u003eDesigned for One Scope\u003c\/h3\u003e\n\n\u003cp\u003eThis reducer\/flattener is not a universal accessory. It's computed and optimized for the field curvature profile of the Astro-Tech AT125EDL 125mm f\/7.8 doublet APO refractor. A generic 0.8x reducer can shorten focal length, but it won't correct the specific curvature of your scope. This one does. It may thread into other f\/7.8 refractors with a 2.5-inch focuser, but optical performance is only guaranteed with the AT125EDL.\u003c\/p\u003e\n\n\u003ch3\u003eHow It Connects\u003c\/h3\u003e\n\n\u003cp\u003eThe scope side threads into the focuser drawtube or the camera angle adjuster (CAA) using M63×1 metric threads — a secure, repeatable connection with no set screws and no wobble. The camera side has standard 48mm T-threads, connecting to a T-ring for DSLR and mirrorless bodies, or directly to dedicated CMOS and CCD astronomy cameras, which come with 48mm T-threads built in.\u003c\/p\u003e\n\n\u003cp\u003eBack focus is 55mm from the shoulder of the reducer to the image plane. That's the standard DSLR spacing — a T-ring and camera body will put you at the correct distance without spacers. For dedicated astronomy cameras, measure your camera's back focus and add spacers if needed to reach 55mm.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\n\u003cul\u003e\n  \u003cli\u003eAstro-Tech AT125EDLRF 0.8x reducer\/field flattener\u003c\/li\u003e\n  \u003cli\u003eSlip-on rubber dust cover for 48mm T-threads (camera side)\u003c\/li\u003e\n  \u003cli\u003eSlip-on dust cover for 2\" scope-side barrel\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e0.8x focal reduction\u003c\/strong\u003e — Converts the AT125EDL from 975mm f\/7.8 to 780mm f\/6.2. That's a 56% increase in photographic speed — the same target reaches the same signal-to-noise ratio in roughly two-thirds the exposure time.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eField flattening\u003c\/strong\u003e — Corrects the native field curvature of the AT125EDL so stars are round and sharp all the way to the corners of your imaging chip.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFully multi-coated optics\u003c\/strong\u003e — Minimizes reflections and maximizes light transmission through the reducer elements.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eM63×1 scope-side thread\u003c\/strong\u003e — Threads securely into the focuser drawtube or camera angle adjuster. No compression ring, no wobble, no shift between sessions.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e48mm T-thread camera connection\u003c\/strong\u003e — DSLR and mirrorless bodies connect via a T-ring (sold separately); dedicated CMOS\/CCD astronomy cameras attach directly — 48mm T-threads are standard on most.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e55mm back focus\u003c\/strong\u003e — Standard DSLR spacing. No spacers needed for most DSLR setups. Dedicated astronomy cameras may require spacers to reach the correct distance.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompact and lightweight\u003c\/strong\u003e — 8 ounces. Adds minimal weight to your imaging train.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eImaging Tip\u003c\/h3\u003e\n\n\u003cp\u003eWhen you first set up the AT125EDLRF, shoot a short test exposure of a star field and inspect the corners at 100% zoom. If stars are elongated radially (pointing away from center), you're too far from the reducer — remove a spacer or check your T-ring stack. If stars are elongated tangentially (perpendicular to the radial direction), you're too close. The 55mm specification is measured from the shoulder of the reducer, not the rear element — make sure you're measuring from the right point.\u003c\/p\u003e\n\n\u003ch3\u003eFAQ\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eWill this work with my AT102EDL or AT150EDL?\u003c\/strong\u003e\u003cbr\u003e\nNo. Each EDL scope has its own dedicated reducer matched to its specific field curvature. The AT102EDL uses the AT102EDLRF, and the AT150EDL uses the AT150EDLRF. They are not interchangeable.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCan I use this visually?\u003c\/strong\u003e\u003cbr\u003e\nThe reducer is designed for prime-focus astrophotography. It will not reach focus with an eyepiece and is not intended for visual use.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDo I need a T-ring?\u003c\/strong\u003e\u003cbr\u003e\nDSLR and mirrorless cameras connect via a T-ring for your specific mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have 48mm T-threads built in and connect directly without a T-ring.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat if I need to use a filter?\u003c\/strong\u003e\u003cbr\u003e\nYou can place a 48mm (2\") threaded filter between the reducer and the camera. Be aware that adding a filter changes your back focus distance — account for the filter thickness when calculating your total spacing.\u003c\/p\u003e\n\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\n\u003cp\u003eIf you're imaging through the AT125EDL, this is the reducer that was designed for it. It flattens the field, speeds the system to f\/6.2, and threads in with a secure M63 connection that doesn't shift between sessions. At 8 ounces, it adds almost nothing to your imaging train. The result is sharper corners, shorter exposures, and a wider field — exactly what the AT125EDL needs to go from a visual scope that happens to image to a proper astrophotography platform.\u003c\/p\u003e\n\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable style=\"width:100%; border-collapse: collapse;\"\u003e\u003ctbody\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eReduction Factor\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e0.8x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eDesigned For\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT125EDL 125mm f\/7.8 Doublet APO Refractor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eNative Focal Length\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e975mm f\/7.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eResulting Focal Length\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e780mm f\/6.2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully multi-coated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eScope-Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eM63×1 metric thread (focuser drawtube or CAA)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCamera-Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e48mm T-threads\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBack Focus\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e55mm (from shoulder of reducer to image plane)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003ePhotographic Speed Increase\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e56% (f\/7.8 to f\/6.2)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e8 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eIncluded\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eReducer\/flattener, T-thread dust cover, scope-side dust cover\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":40481994276937,"sku":"AT125EDLRF","price":199.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/0.8XReducer_Flattener_1-10522_3885e071-8109-44bc-8473-2f2480333cd7.jpg?v=1714677371"},{"product_id":"astro-tech-0-8x-reducer-field-flattener-for-astro-tech-at90cft-triplet-apo-refractor","title":"Astro-Tech 0.8x Reducer\/Field Flattener for Astro-Tech AT90CFT and AT90EDX Triplet APO Refractor","description":"\u003cp\u003eThe AT90CFT and AT90EDX are excellent visual scopes at 540mm f\/6, but if you're imaging through either one, you already know the two things an f\/6 refractor does to your photos: it curves the field and it makes you wait. Stars that are pin-sharp in the center turn into little comets near the corners. And at f\/6, you need longer exposures to pull faint nebulosity out of the background. The AT90CFTRF fixes both problems in one piece of glass. It reduces the focal length to 432mm, speeding the system to f\/4.8 — a 56% increase in photographic speed — and it flattens the field so stars stay round and tight all the way to the corners of your imaging chip.\u003c\/p\u003e\n\u003ch3\u003eDesigned for Two Scopes\u003c\/h3\u003e\n\u003cp\u003eThis reducer\/flattener is not a universal fit. It's designed and optimized specifically for the Astro-Tech AT90CFT (carbon fiber tube) and AT90EDX (aluminum tube) 90mm f\/6 triplet APO refractors. The optical correction is matched to the curvature profile of those two scopes, which is why the stars come out round across the field instead of trailing into elongated shapes at the edges. A generic 0.8x reducer can reduce focal length, but it won't correct the specific field curvature of your scope. This one does.\u003c\/p\u003e\n\u003ch3\u003eHow It Connects\u003c\/h3\u003e\n\u003cp\u003eThe scope side threads into the focuser or camera angle adjuster using M63×1 metric threads — a secure, repeatable connection that doesn't shift between sessions. No set screws, no compression ring, no wobble. The camera side has standard 48mm T-threads, connecting to a T-ring for DSLR and mirrorless bodies, or directly to dedicated CMOS and CCD astronomy cameras, which come with 48mm T-threads built in.\u003c\/p\u003e\n\u003cp\u003eBack focus is 55mm from the shoulder of the reducer to the image plane. That's the standard DSLR spacing — meaning a T-ring and camera body will put you at the correct distance without spacers or adjustments. For dedicated astronomy cameras, you may need a short spacer to reach the same 55mm. Check your camera's back focus specification and add spacers if needed.\u003c\/p\u003e\n\u003ch3\u003eBuilt-In Filter Holder\u003c\/h3\u003e\n\u003cp\u003eThe top cap of the reducer unthreads from the body, exposing a 48mm filter holder on the underside. This lets you place a 2\" threaded filter — a light pollution filter, narrowband filter, or UV\/IR cut — directly into the optical path without adding a separate filter drawer to your imaging train. One less piece of hardware between the scope and the sensor, and one less source of spacing error or tilt.\u003c\/p\u003e\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eAstro-Tech AT90CFTRF 0.8x reducer\/field flattener\u003c\/li\u003e\n\u003cli\u003eSlip-on rubber dust cover for 48mm T-threads (camera side)\u003c\/li\u003e\n\u003cli\u003eSlip-on dust cover for scope-side barrel\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e0.8x focal reduction — 540mm f\/6 becomes 432mm f\/4.8\u003c\/strong\u003e — A 56% increase in photographic speed (light per pixel). Shorter exposures to reach the same signal, or deeper images in the same exposure time. Either way, your total imaging time per target drops significantly.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eField flattening corrects edge-of-field curvature\u003c\/strong\u003e — Refractors curve the focal plane. Without correction, stars in the outer third of the field elongate into streaks or comets. The flattener brings the entire field into focus on a flat imaging sensor, producing round stars corner to corner.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully multi-coated optics\u003c\/strong\u003e — All air-to-glass surfaces are multi-coated to minimize reflections and maintain contrast. Important in a reducer that sits in the optical path of every photon reaching your sensor.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM63×1 threaded scope connection\u003c\/strong\u003e — Threads securely into the AT90CFT\/AT90EDX focuser or camera angle adjuster. No compression ring, no play — a solid, repeatable mechanical connection that eliminates tilt between sessions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48mm T-thread camera connection\u003c\/strong\u003e — DSLR and mirrorless bodies connect via a T-ring (sold separately); dedicated CMOS\/CCD astronomy cameras attach directly — 48mm T-threads are standard on most.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e55mm back focus (standard DSLR spacing)\u003c\/strong\u003e — A T-ring and DSLR body reach focus without spacers. Dedicated astronomy cameras may need a short spacer depending on their native back focus distance. The product manual includes spacing diagrams.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntegrated 48mm filter holder\u003c\/strong\u003e — Unthread the top cap to access a built-in 2\" filter holder. Accepts standard 48mm threaded filters — narrowband, UHC, UV\/IR cut — without adding a separate filter drawer to the imaging train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLightweight (9 oz)\u003c\/strong\u003e — Adds minimal weight to your imaging train. Won't stress the focuser or shift balance on a light mount.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eObserving Tip\u003c\/h3\u003e\n\u003cp\u003eGet the 55mm back focus right before you shoot a single frame. Measure from the shoulder of the reducer — the flat face where it meets the focuser — to your camera sensor. For a DSLR with a T-ring, 55mm is usually automatic. For a dedicated astronomy camera, add up the T-ring or adapter thickness, any spacers, and the camera's flange-to-sensor distance. If the total is less than 55mm, add spacers. If it's more, you'll need a shorter adapter or fewer spacers. Getting this measurement right is the single biggest factor in whether your corner stars are round or elongated. The product manual has a spacing diagram — use it.\u003c\/p\u003e\n\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Do I need a T-ring?\u003c\/strong\u003e\u003cbr\u003eIf you're using a DSLR or mirrorless camera, yes — you need a T-ring for your specific camera mount (sold separately). The reducer's camera side has 48mm T-threads that connect to the T-ring. If you're using a dedicated CMOS or CCD astronomy camera, no T-ring is needed — those cameras typically have 48mm T-threads built in and connect directly to the reducer.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Can I use filters with this reducer?\u003c\/strong\u003e\u003cbr\u003eYes. Unthread the top cap of the reducer to expose a built-in 48mm filter holder on the underside. Standard 2\" threaded filters (48mm) thread right in — narrowband, light pollution, UV\/IR cut. The filter sits inside the reducer body, keeping your imaging train compact.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What's the correct back focus distance?\u003c\/strong\u003e\u003cbr\u003e55mm from the shoulder of the reducer (where it meets the focuser) to the image plane (your camera sensor). For a DSLR with a standard T-ring, this spacing is typically automatic. For a dedicated astronomy camera, you may need to add spacers to reach 55mm. Incorrect spacing is the most common cause of elongated corner stars — it's worth measuring carefully. The included product manual has a spacing diagram for common camera configurations.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: How much faster is f\/4.8 compared to f\/6?\u003c\/strong\u003e\u003cbr\u003eAbout 56% faster in terms of light gathered per pixel per unit time. In practical terms, if you were shooting 5-minute exposures at f\/6 to reach a certain signal level, you'd reach the same level in roughly 3 minutes and 12 seconds at f\/4.8. Over a multi-hour session, that adds up to significantly more data or significantly less time on each target.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Will this work for visual observing?\u003c\/strong\u003e\u003cbr\u003eTechnically yes — it will reduce magnification and widen the field, and the flattening will improve edge sharpness in wide-field eyepieces. But it's designed and optimized for photographic use with a flat sensor, not for visual observing through an eyepiece. Most AT90CFT\/AT90EDX owners use the reducer strictly for imaging and observe without it.\u003c\/p\u003e\n\u003ch3\u003eOptional Accessories\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e48mm T-Ring (for your camera mount)\u003c\/strong\u003e — Required for DSLR and mirrorless cameras. Available for Canon EF, Nikon F, Sony E, and other mounts. The T-ring threads onto the reducer's 48mm camera-side connection and adapts it to your camera body. Not needed for dedicated CMOS\/CCD astronomy cameras.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48mm Threaded Filters\u003c\/strong\u003e — Light pollution, narrowband (H-alpha, O-III, S-II), or UV\/IR cut filters thread directly into the reducer's built-in filter holder. No separate filter drawer required.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpacer Rings (if using a dedicated astronomy camera)\u003c\/strong\u003e — Needed to achieve the 55mm back focus distance with cameras that have a shorter native back focus than a DSLR. Available in various thicknesses (e.g., 11mm, 16.5mm, 21mm). Check your camera's specs and add spacers to make up the difference.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\u003cp\u003eIf you own an AT90CFT or AT90EDX and you're imaging with it, this is not an optional accessory — it's the other half of the imaging system. The scope gives you the light and the color correction. The reducer gives you the speed and the flat field. Stars round to the corners, exposures cut by more than a third, and the whole thing threads together without adapters or guesswork. Dedicated, matched, done.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eProduct Type\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFocal reducer and field flattener\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eReduction Factor\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e0.8x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCompatible Telescopes\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT90CFT and AT90EDX 90mm f\/6 triplet APO refractors\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eResulting Focal Length\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e432mm (from 540mm native)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eResulting Focal Ratio\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003ef\/4.8 (from f\/6 native)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully multi-coated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eScope-Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eM63×1 metric thread (threads into focuser or camera angle adjuster)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCamera-Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e48mm T-thread\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBack Focus\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e55mm (shoulder of reducer to image plane)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFilter Holder\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eBuilt-in 48mm (2\") threaded filter holder (accessible by unthreading top cap)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e9 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eIncluded\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eReducer\/flattener, slip-on rubber cover for T-threads, slip-on cover for scope-side barrel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eProduct Manual\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eIncluded (PDF download on product page)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1 year manufacturer warranty\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":41403600961609,"sku":"AT90CFTRF","price":199.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/image_fd016b25-9d57-4773-9219-2d18891ff86c.jpg?v=1716199025"},{"product_id":"explore-scientific-2-field-flattener-for-imaging-for-f-5-to-f-7-refractors","title":"Explore Scientific 2\" Field Flattener for Imaging for f\/5 to f\/7 Refractors","description":"\u003ch3 data-end=\"277\" data-start=\"194\"\u003eExplore Scientific 2\" Field Flattener – Precision Imaging for Fast Refractors\u003c\/h3\u003e\n\u003cp data-end=\"684\" data-start=\"279\"\u003eIf you're a deep-sky astrophotographer using a fast refractor, you’ve likely encountered the frustration of field curvature—stars near the center of your image look pinpoint sharp, but those toward the edges turn into bloated, misshapen blurs. That’s where the \u003cstrong data-end=\"581\" data-start=\"540\"\u003eExplore Scientific 2\" Field Flattener\u003c\/strong\u003e steps in, offering a simple yet powerful solution to transform your telescope’s imaging performance.\u003c\/p\u003e\n\u003cp data-end=\"1114\" data-start=\"686\"\u003eDesigned for refractors with focal ratios between \u003cstrong data-end=\"751\" data-start=\"736\"\u003ef\/5 and f\/7\u003c\/strong\u003e, this high-quality optical accessory ensures your stars remain sharp and well-defined across the entire field of view, eliminating the curved focal plane that distorts stars at the periphery of your images. Whether you’re capturing wide-field nebulae, open clusters, or galaxies, this flattener helps you maximize the full potential of your refractor’s optics.\u003c\/p\u003e\n\u003ch4 data-end=\"1153\" data-start=\"1116\"\u003e\u003cstrong data-end=\"1151\" data-start=\"1121\"\u003eWhy Use a Field Flattener?\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cp data-end=\"1510\" data-start=\"1154\"\u003eRefractors, especially faster ones, inherently suffer from field curvature—a natural optical aberration that causes stars to appear in focus at the center while progressively blurring toward the edges. This is particularly noticeable in full-frame or APS-C sensor astrophotography, where the larger sensor size reveals these distortions more prominently.\u003c\/p\u003e\n\u003cp data-end=\"1755\" data-start=\"1512\"\u003eThe \u003cstrong data-end=\"1557\" data-start=\"1516\"\u003eExplore Scientific 2\" Field Flattener\u003c\/strong\u003e corrects this issue by adjusting the light path so that every star, from the center to the very edge, lands on the same focal plane. The result? Stunning, pinpoint stars across your entire image.\u003c\/p\u003e\n\u003ch4 data-end=\"1780\" data-start=\"1757\"\u003e\u003cstrong data-end=\"1778\" data-start=\"1762\"\u003eKey Features\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cul data-end=\"2806\" data-start=\"1782\"\u003e\n\u003cli data-end=\"1970\" data-start=\"1782\"\u003e\n\u003cstrong data-end=\"1823\" data-start=\"1784\"\u003eOptimized for f\/5 to f\/7 refractors\u003c\/strong\u003e – Designed to match the optical characteristics of fast refractors, providing the best balance of correction for a wide range of imaging setups.\u003c\/li\u003e\n\u003cli data-end=\"2115\" data-start=\"1971\"\u003e\n\u003cstrong data-end=\"1999\" data-start=\"1973\"\u003eLarge 2\" barrel design\u003c\/strong\u003e – Ensures full-frame sensor coverage without vignetting, preserving a bright, even field across your astrophotos.\u003c\/li\u003e\n\u003cli data-end=\"2274\" data-start=\"2116\"\u003e\n\u003cstrong data-end=\"2147\" data-start=\"2118\"\u003eFully multi-coated optics\u003c\/strong\u003e – Reduces reflections and increases light transmission, improving contrast and preserving faint details in deep-sky objects.\u003c\/li\u003e\n\u003cli data-end=\"2456\" data-start=\"2275\"\u003e\n\u003cstrong data-end=\"2301\" data-start=\"2277\"\u003eThreaded for filters\u003c\/strong\u003e – The 2\" nosepiece includes standard filter threads, allowing you to seamlessly integrate light pollution or narrowband filters into your imaging train.\u003c\/li\u003e\n\u003cli data-end=\"2658\" data-start=\"2457\"\u003e\n\u003cstrong data-end=\"2490\" data-start=\"2459\"\u003eVersatile camera connection\u003c\/strong\u003e – The flattener terminates in a standard \u003cstrong data-end=\"2548\" data-start=\"2532\"\u003eM42 T-thread\u003c\/strong\u003e, making it easy to attach most DSLR and dedicated astronomy cameras with the appropriate T-ring or adapter.\u003c\/li\u003e\n\u003cli data-end=\"2806\" data-start=\"2659\"\u003e\n\u003cstrong data-end=\"2687\" data-start=\"2661\"\u003eAll-metal construction\u003c\/strong\u003e – A robust and precisely machined aluminum housing ensures durability while maintaining excellent optical alignment.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4 data-end=\"2853\" data-start=\"2808\"\u003e\u003cstrong data-end=\"2851\" data-start=\"2813\"\u003eHow It Works in Your Imaging Setup\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cp data-end=\"3237\" data-start=\"2854\"\u003eUsing the \u003cstrong data-end=\"2905\" data-start=\"2864\"\u003eExplore Scientific 2\" Field Flattener\u003c\/strong\u003e is as simple as inserting it into your focuser, attaching your camera, and fine-tuning your back focus. This flattener is designed for use with \u003cstrong data-end=\"3072\" data-start=\"3050\"\u003e55mm of back focus\u003c\/strong\u003e, which is standard for most astrophotography setups, meaning it will work seamlessly with your DSLR and T-ring or dedicated astro camera with appropriate spacers.\u003c\/p\u003e\n\u003cp data-end=\"3540\" data-start=\"3239\"\u003eIf you’re unsure about your specific back focus requirements, adjusting with additional extension rings may be necessary for optimal performance. The results, however, are well worth it—razor-sharp stars across your entire image, making your astrophotos look more professional and visually striking.\u003c\/p\u003e\n\u003ch4 data-end=\"3588\" data-start=\"3542\"\u003e\u003cstrong data-end=\"3586\" data-start=\"3547\"\u003eWho Should Consider This Flattener?\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cp data-end=\"3905\" data-start=\"3589\"\u003eThis field flattener is a must-have for astrophotographers using fast refractors who want to eliminate edge distortions without altering their telescope’s native focal length. It’s particularly well-suited for those with \u003cstrong data-end=\"3862\" data-start=\"3810\"\u003e80mm to 130mm refractors in the f\/5 to f\/7 range\u003c\/strong\u003e, ensuring a wide range of compatibility.\u003c\/p\u003e\n\u003cp data-end=\"4088\" data-start=\"3907\"\u003eFor those looking to enhance their imaging without the added complexity of a reducer-flattener combo, this straightforward, high-performance solution delivers exceptional results.\u003c\/p\u003e\n\u003ch4 data-end=\"4115\" data-start=\"4090\"\u003e\u003cstrong data-end=\"4113\" data-start=\"4095\"\u003eFinal Thoughts\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cp data-end=\"4481\" data-start=\"4116\"\u003eAstrophotography demands precision, and the \u003cstrong data-end=\"4201\" data-start=\"4160\"\u003eExplore Scientific 2\" Field Flattener\u003c\/strong\u003e is an essential tool for anyone looking to achieve stunning, flat-field images with their fast refractor. With its premium optics, durable build, and simple integration into your imaging train, this flattener is a game-changer for capturing deep-sky objects in all their glory.\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eNOTE: This device is for photographic use only. It is NOT intended for visual use.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e8 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e1 year, extendable to lifetime\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c!----\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":41403619934281,"sku":"ES2FF","price":119.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/image_0792a453-a8be-4af6-9c35-f507b9b9706a.jpg?v=1716201191"},{"product_id":"zwo-0-7x-reducer-for-ff107apo-and-ff130apo-telescopes","title":"ZWO 0.7x Reducer for FF107APO and FF130APO Telescopes","description":"\u003cp\u003e\u003cspan\u003eIf you are needing a faster version of your ZWO FF107APO or FF130APO, this reducer will get you there.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"UTF-8\"\u003eZWO has released a new 3-inch 0.7× full frame reducer that is compatible with the FF107APO and FF130APO telescopes. It has a three-element optical design, including one element made of ED glass. Its reduction factor is 0.7, which gives the FF107APO a shortened focal ratio of f\/4.9 and a shorter focal length of 524mm. This allows for less total integration time and a wider field of view, bringing more convenience and possibilities for your wide-field deep-sky imaging. The reducer has a standard 55mm back focus and comes with M68, M54, and M48 threaded adapters for easy attachment. Connecting to the APO is fairly simple. Prepare the FF107APO telescope tube and the focal reducer. Unscrew the M86 to 2-inch adapter at the end of the FF107APO telescope tube. Unscrew the end cap of the 0.7X reducer. Insert the reducer into the focuser inner tube and tighten it.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eTech Details: \u003c\/span\u003e\u003c\/h2\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c!----\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":41455635693641,"sku":"ZWOF107130RE","price":399.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/image_99398898-91b7-498c-94d2-e56746455bef.jpg?v=1723838450"},{"product_id":"zwo-0-76x-reducer-for-ff80apo-telescope","title":"ZWO 0.76x Reducer for FF80APO Telescope","description":"\u003cp\u003eIf you are needing a faster version of your ZWO FF80APO Quad, this reducer will take your f\/ratio from f\/7.5 to f\/5.7.\u003c\/p\u003e\n\u003cp\u003eZWO has also released a new 3-inch FF80APO 0.76X full frame reducer with a three-element optical design, including one element made of ED glass. Its reduction factor is 0.76x, which gives the FF80APO f\/7.5 astrograph a shortened focal ratio of f\/5.7 and a shorter focal length of 312mm. This allows for less total integration time and a wider field of view, bringing more convenience and possibilities for your wide-field deep sky imaging.\u003c\/p\u003e\n\u003cp\u003eThe reducer has a rear interface that attaches to the FF80APO telescope tube’s included four-segment camera extension tube. The back focus is the standard 55mm, and it has a built-in M48X0.75 2-inch filter thread for easy attachment.\u003c\/p\u003e\n\u003cp\u003eConnecting to the APO is fairly simple.\u003c\/p\u003e\n\u003cp\u003ePrepare the FF80APO telescope tube and the focal reducer.\u003cbr\u003eUnscrew the four-segment connector at the end of the FF80APO telescope tube.\u003cbr\u003eUnscrew the end cap of the 0.76X reducer and attach it to the M68 thread of the four-segment connector.\u003cbr\u003eUnscrew the front cap of the reducer, insert it into the focuser inner tube, and tighten it.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003cbr\u003e\n\u003c\/h2\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c!----\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":41465415073865,"sku":"ZWOF80RE","price":299.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/image_d751a2e8-e1ab-44eb-aa99-d34d194c22df.jpg?v=1723838414"},{"product_id":"astro-tech-0-8x-reducer-field-flattener-for-astro-tech-at80edl-doublet-apo-refractor","title":"Astro-Tech 0.8x Reducer\/Field Flattener for Astro-Tech AT80EDL Doublet APO Refractor","description":"\u003cp\u003eThe AT80EDLRF is the dedicated 0.8× reducer and field flattener for the Astro-Tech AT80EDL f\/7 doublet APO refractor. It does two things at once: it reduces the AT80EDL's 560mm f\/7 focal length to 448mm f\/5.6 — almost a full stop faster — and it flattens the field, delivering sharp, round stars from the center of the sensor to the corners. Without a flattener, every refractor produces a curved focal plane. Stars in the center are sharp, but stars toward the edges of the frame elongate as the curved image surface diverges from the flat sensor. The AT80EDLRF corrects that curvature and gives you a flat field across DSLR and dedicated astronomy camera sensors.\u003c\/p\u003e\n\n\u003cp\u003eAt f\/5.6, exposures are shorter, the field of view is wider, and the system is better matched to the fast download cycles of modern CMOS cameras. If the AT80EDL is your imaging platform, this is the reducer designed for it.\u003c\/p\u003e\n\n\u003ch3\u003eDesigned for the AT80EDL\u003c\/h3\u003e\n\n\u003cp\u003eThe AT80EDLRF is optically matched to the AT80EDL's doublet FCD-100 objective. It threads directly into the camera angle adjuster (CAA) on the AT80EDL's focuser drawtube via M63×1 threads on the scope side. The camera side has standard 48mm T-threads (M48×0.75) — DSLR and mirrorless cameras connect via a T-ring for your specific mount (sold separately), while dedicated CMOS and CCD astronomy cameras typically have 48mm T-threads built in and connect directly without a T-ring.\u003c\/p\u003e\n\n\u003cp\u003eWhile the AT80EDLRF may physically thread into other f\/7 refractors that use a 2.5\" focuser with M63 threads, its optical correction is designed around the AT80EDL's specific optical system. Performance with other scopes is not guaranteed.\u003c\/p\u003e\n\n\u003ch3\u003eBackfocus and Spacing\u003c\/h3\u003e\n\n\u003cp\u003eBackfocus is 55mm from the shoulder of the reducer to the image plane — the standard spacing for DSLR camera bodies with a T-ring. If you're using a dedicated astronomy camera, you may need spacers to achieve the correct 55mm distance, depending on your camera's backfocus requirement. The optical diagram provided on this page shows exact dimensions for calculating your imaging train spacing.\u003c\/p\u003e\n\n\u003ch3\u003eBuilt-In Filter Access\u003c\/h3\u003e\n\n\u003cp\u003eThe top section of the AT80EDLRF unscrews from the body, exposing 48mm filter threads on the underside of the removed cap. This lets you thread a standard 2\" (48mm) filter — narrowband, light pollution, UV\/IR cut — directly into the optical path without adding a separate filter drawer or changing your backfocus distance. The filter sits between the reducer optics and the telescope, in the correct position for the converging light cone.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eAT80EDLRF 0.8× reducer\/field flattener\u003c\/li\u003e\n  \u003cli\u003eSlip-on rubber dust cover (camera-side T-threads)\u003c\/li\u003e\n  \u003cli\u003eSlip-on dust cover (scope-side barrel)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e0.8× focal reduction — 560mm f\/7 becomes 448mm f\/5.6.\u003c\/strong\u003e Almost a full stop faster. Shorter exposures, wider field, and better matched to fast-readout CMOS cameras.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eField flattener corrects the AT80EDL's native field curvature.\u003c\/strong\u003e Round, sharp stars from center to corners across DSLR and dedicated astronomy camera sensors. No edge elongation.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDesigned specifically for the AT80EDL doublet APO.\u003c\/strong\u003e Optically matched to the AT80EDL's FCD-100 objective. Threads directly into the CAA via M63×1 threads.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFully multicoated optics.\u003c\/strong\u003e All air-to-glass surfaces carry broadband multicoatings for high light transmission and minimal scatter.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e48mm T-threads on the camera side.\u003c\/strong\u003e DSLR and mirrorless bodies connect via a T-ring (sold separately); dedicated CMOS\/CCD astronomy cameras attach directly — 48mm T-threads are standard on most.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e55mm backfocus — standard DSLR spacing.\u003c\/strong\u003e A T-ring and DSLR body typically land right at the correct distance. Astronomy cameras may need spacers.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBuilt-in 48mm filter access.\u003c\/strong\u003e Unscrew the top cap to thread a 2\" filter directly into the optical path. No separate filter drawer needed.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompact and lightweight.\u003c\/strong\u003e 67mm diameter, 71.51mm long, 8 oz. Adds minimal weight and length to the imaging train.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eDo I need this reducer, or can I use a generic field flattener?\u003c\/strong\u003e\u003cbr\u003e\nThe AT80EDLRF is designed to match the AT80EDL's specific optical curve. A generic flattener may not correct the field as well, and a generic reducer will almost certainly introduce coma or other aberrations that the matched reducer avoids. For best results with the AT80EDL, this is the one to use.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCan I use this as a 1× flattener without the reduction?\u003c\/strong\u003e\u003cbr\u003e\nNo. The AT80EDLRF is a combined reducer\/flattener — it always reduces to 0.8×. If you want flat-field correction at the native 560mm f\/7 focal length, you would need a dedicated 1× field flattener (not currently offered for the AT80EDL in the Astro-Tech line).\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWill this work on my AT102EDL or AT125EDL?\u003c\/strong\u003e\u003cbr\u003e\nEach EDL scope has its own dedicated reducer\/flattener. The product manual PDF is shared across the AT80EDL, AT102EDL, and AT125EDL models, but the reducers themselves are separate SKUs matched to each scope's optics. Use the reducer designated for your specific scope.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eHow do I connect my camera?\u003c\/strong\u003e\u003cbr\u003e\nDSLR and mirrorless cameras connect via a T-ring for your specific mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have 48mm T-threads built in and connect directly without a T-ring. The 55mm backfocus is measured from the reducer's shoulder to the sensor plane.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCan I use filters with this reducer?\u003c\/strong\u003e\u003cbr\u003e\nYes. Unscrew the top cap of the reducer to access the built-in 48mm filter threads. Standard 2\" (48mm) threaded filters — narrowband, LP, UV\/IR cut — thread in directly. This keeps the filter in the correct optical path position without adding a separate filter drawer.\u003c\/p\u003e\n\n\u003ch3\u003eAccessories\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eT-ring for your camera mount (sold separately):\u003c\/strong\u003e Required for connecting DSLR and mirrorless cameras. Available for Canon EOS, Nikon F, Sony E, and other mounts. Dedicated CMOS\/CCD astronomy cameras connect directly via 48mm T-threads.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e48mm (2\") filters:\u003c\/strong\u003e Narrowband, light pollution, UV\/IR cut filters thread directly into the reducer's built-in filter holder.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\n\u003cp\u003eThe AT80EDLRF does what a matched reducer\/flattener should do: it makes the AT80EDL a faster, wider-field imaging system with a flat, corrected field — and it does it in a compact, 8-ounce package that threads directly into the focuser's camera angle adjuster. If you're imaging with the AT80EDL, this is the reducer designed for your scope. The 48mm T-threads connect to your camera, the built-in filter access keeps your optical train simple, and the 55mm backfocus is standard DSLR spacing. One piece, one connection, no guesswork on optical matching.\u003c\/p\u003e\n\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable style=\"width:100%; border-collapse: collapse;\"\u003e\n  \u003ctbody\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eModel\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT80EDLRF\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eType\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e0.8× Focal Reducer \/ Field Flattener\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eDesigned For\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT80EDL f\/7 Doublet APO Refractor\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eReduction Factor\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e0.8× (560mm f\/7 → 448mm f\/5.6)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully multicoated\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eScope-Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eM63×1 thread (threads into AT80EDL CAA)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCamera-Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e48mm T-threads (M48×0.75)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBackfocus\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e55mm (shoulder to image plane)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFilter Access\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eBuilt-in 48mm (2\") filter threads (unscrew top cap)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eOuter Diameter\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e67mm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eLength\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e71.51mm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e8 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":41563280179273,"sku":"AT80EDLRF","price":199.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/image_77f092f7-7870-4303-9f89-e6f56f5e2d65.jpg?v=1719596318"},{"product_id":"sky-watcher-evoguide-50ed-flattener","title":"Sky-Watcher EvoGuide 50ED Flattener","description":"\u003cp data-start=\"261\" data-end=\"343\" class=\"\"\u003e\u003cstrong data-start=\"261\" data-end=\"343\"\u003eSky-Watcher Field Flattener for EvoGuide 50DX – Bring Sharpness to the Corners\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"345\" data-end=\"670\" class=\"\"\u003eIf you're using the Sky-Watcher EvoGuide 50DX as a wide-field astrograph, the dedicated Field Flattener is a must-have accessory. This simple yet essential optical corrector transforms your compact ED refractor into a fully capable imaging telescope, delivering pinpoint stars from edge to edge—even on larger camera sensors.\u003c\/p\u003e\n\u003ch3 data-start=\"672\" data-end=\"706\" class=\"\"\u003eWhy You Need a Field Flattener\u003c\/h3\u003e\n\u003cp data-start=\"708\" data-end=\"1045\" class=\"\"\u003eRefractors—especially fast, short focal length models like the EvoGuide 50DX—are known for producing a curved field. While the center of your image may be razor-sharp, the edges can appear soft or stretched when paired with modern DSLR, mirrorless, or cooled CMOS cameras. This is especially noticeable with APS-C and full-frame sensors.\u003c\/p\u003e\n\u003cp data-start=\"1047\" data-end=\"1364\" class=\"\"\u003eThat’s where the field flattener comes in. It’s designed specifically for the EvoGuide 50DX’s optical system to correct this curvature and expand the usable field of view. With the flattener in place, you get a flat, distortion-free field that maintains stellar sharpness across the entire frame—no cropping required.\u003c\/p\u003e\n\u003ch3 data-start=\"1366\" data-end=\"1400\" class=\"\"\u003eOptimized for Astrophotography\u003c\/h3\u003e\n\u003cp data-start=\"1402\" data-end=\"1637\" class=\"\"\u003eThis field flattener provides a 1.0x magnification, meaning it won’t alter the focal length of the EvoGuide 50DX. You'll still enjoy the same fast f\/4.8 imaging speed and wide field, but now with improved performance across the sensor.\u003c\/p\u003e\n\u003cp data-start=\"1639\" data-end=\"1919\" class=\"\"\u003eIt’s engineered to deliver optimal correction at the standard 55mm backfocus, making it a seamless match for most DSLR and mirrorless camera setups using a T-ring. For dedicated astro cameras, the backfocus spacing remains just as easy to manage with standard spacers or adapters.\u003c\/p\u003e\n\u003ch3 data-start=\"1921\" data-end=\"1954\" class=\"\"\u003eThreaded for Easy Integration\u003c\/h3\u003e\n\u003cp data-start=\"1956\" data-end=\"2351\" class=\"\"\u003eSky-Watcher designed the flattener with versatility in mind. The rear threads are standard M48, allowing for wide T-ring connections that reduce vignetting—particularly important if you’re using a full-frame sensor. The front threads attach directly to the EvoGuide 50DX focuser, providing a secure, threaded connection that keeps your optical train aligned and stable throughout long exposures.\u003c\/p\u003e\n\u003cp data-start=\"2353\" data-end=\"2426\" class=\"\"\u003eNo wobble, no sag—just a tight, solid fit for better imaging consistency.\u003c\/p\u003e\n\u003ch3 data-start=\"2428\" data-end=\"2471\" class=\"\"\u003eCompact, Lightweight, and Purpose-Built\u003c\/h3\u003e\n\u003cp data-start=\"2473\" data-end=\"2787\" class=\"\"\u003eJust like the EvoGuide itself, the flattener is compact and lightweight, so it won’t upset your mount’s balance or overtax a portable tracking rig. It’s designed exclusively for the EvoGuide 50DX, ensuring the optical spacing and correction are precisely dialed in—something you won’t get from a generic flattener.\u003c\/p\u003e\n\u003cp data-start=\"2789\" data-end=\"3050\" class=\"\"\u003eIf you’re using the EvoGuide 50DX for imaging and haven’t added the field flattener yet, you’re leaving performance on the table. Whether you’re shooting large nebulae or rich star fields, this accessory helps you get the most out of your scope and your camera.\u003c\/p\u003e\n\u003chr data-start=\"3052\" data-end=\"3055\" class=\"\"\u003e\n\u003ch3 data-start=\"3057\" data-end=\"3072\" class=\"\"\u003eHighlights:\u003c\/h3\u003e\n\u003cul data-start=\"3074\" data-end=\"3465\"\u003e\n\u003cli data-start=\"3074\" data-end=\"3152\" class=\"\"\u003e\n\u003cp data-start=\"3076\" data-end=\"3152\" class=\"\"\u003e\u003cstrong data-start=\"3076\" data-end=\"3152\"\u003eFlattens the field of the EvoGuide 50DX for sharp stars across the frame\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3153\" data-end=\"3223\" class=\"\"\u003e\n\u003cp data-start=\"3155\" data-end=\"3223\" class=\"\"\u003e\u003cstrong data-start=\"3155\" data-end=\"3223\"\u003e1.0x design preserves original focal length and fast f\/4.8 speed\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3224\" data-end=\"3268\" class=\"\"\u003e\n\u003cp data-start=\"3226\" data-end=\"3268\" class=\"\"\u003e\u003cstrong data-start=\"3226\" data-end=\"3268\"\u003eIdeal for APS-C and full-frame sensors\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3269\" data-end=\"3322\" class=\"\"\u003e\n\u003cp data-start=\"3271\" data-end=\"3322\" class=\"\"\u003e\u003cstrong data-start=\"3271\" data-end=\"3322\"\u003eM48 threads for wide, secure camera connections\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3323\" data-end=\"3393\" class=\"\"\u003e\n\u003cp data-start=\"3325\" data-end=\"3393\" class=\"\"\u003e\u003cstrong data-start=\"3325\" data-end=\"3393\"\u003e55mm backfocus spacing for easy DSLR and astro cam compatibility\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3394\" data-end=\"3465\" class=\"\"\u003e\n\u003cp data-start=\"3396\" data-end=\"3465\" class=\"\"\u003e\u003cstrong data-start=\"3396\" data-end=\"3465\"\u003ePurpose-built for the EvoGuide 50DX—perfect fit and optical match\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"3467\" data-end=\"3748\" class=\"\"\u003eThis isn't just an upgrade—it's the final piece that turns your EvoGuide 50DX into a true wide-field astrograph. Whether you're a beginner wanting better stars or an advanced imager fine-tuning your setup, the Sky-Watcher Field Flattener makes a visible difference where it counts.\u003c\/p\u003e","brand":"Sky-Watcher","offers":[{"title":"Default Title","offer_id":41593635012681,"sku":"S20214","price":115.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/S20214_Evo50_Flat_web_1800x1800_a09c7201-4512-409d-aba3-ba1c4c5e6e36.webp?v=1723135807"},{"product_id":"astro-tech-1x-field-flattener-for-astro-tech-at80edt-triplet-apo-refractor","title":"Astro-Tech 1X Field Flattener For Astro-Tech AT80EDT Triplet APO Refractor","description":"\u003cp\u003eThe AT80EDT is one of our most popular grab-and-go imaging refractors — 80mm of FK-61 triplet glass at 480mm f\/6, compact enough for airline travel and light enough for small mounts, but sharp enough for serious deep-sky work. At f\/6, the field curves. Stars in the center are tight. Stars toward the edges stretch. That's not a flaw in the scope — it's what any uncorrected refractor does to a flat sensor. A dedicated field flattener fixes it.\u003c\/p\u003e\n\u003cp\u003eThe AT80EDTFF is a 1× flattener designed specifically for the AT80EDT. It doesn't reduce the focal length or change the focal ratio — you keep the full 480mm at f\/6. What it does is flatten the field so stars are round and sharp across your sensor. The AT80EDT delivers the light. The flattener makes sure that light lands correctly on the chip.\u003c\/p\u003e\n\u003ch3\u003eSensor Coverage — What to Expect\u003c\/h3\u003e\n\u003cp\u003eThe AT80EDTFF delivers excellent correction across APS-C sensors (roughly 22×15mm) and smaller — round, tight stars from center to edge. On full-frame sensors (36×24mm), you may see some residual curvature at the extreme corners. This is an 80mm scope at f\/6, and the corrected image circle has its limits. For most APS-C imaging — which is the sensor size most commonly paired with an 80mm refractor — the flattener does exactly what it needs to do. If you're planning to image full-frame with the AT80EDT, consider testing your specific camera to see if the corner performance meets your standards, or use cropping in processing.\u003c\/p\u003e\n\u003ch3\u003eWhy 1× Instead of a Reducer?\u003c\/h3\u003e\n\u003cp\u003eWe also make a 0.8× reducer\/field flattener for the AT80EDT. That drops the focal length to 384mm at f\/4.8 — faster exposures and a wider field, but a different image scale and a different set of targets that frame well. The 1× flattener is for imagers who want the AT80EDT's native 480mm focal length. At 480mm, mid-size targets — the Horsehead and Flame region, the Pleiades, the Orion Nebula complex, galaxy groups — have enough scale to show detail without being so large they clip the field. The flattener keeps the image scale and just fixes the field curvature.\u003c\/p\u003e\n\u003ch3\u003eConnection and Installation\u003c\/h3\u003e\n\u003cp\u003eThe scope side of the AT80EDTFF has an M63 threaded connection that threads directly onto the AT80EDT focuser drawtube — or onto the Camera Angle Adjuster if you're using the rotation feature. No barrel insert. No adapter. Just threads — secure, repeatable, and square to the optical axis every time you set up.\u003c\/p\u003e\n\u003cp\u003eThe camera side terminates in 48mm T-threads. DSLR and mirrorless bodies connect via a T-ring for your specific camera mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have 48mm T-threads built in and connect directly without a T-ring.\u003c\/p\u003e\n\u003cp\u003eBack focus is 55mm from the flattener's shoulder to the sensor. ZWO filter wheel + OAG + camera stacks are designed for 55mm and bolt together directly. A DSLR with a standard T-ring typically hits the spacing naturally. Dedicated cameras with different flange distances may need 48mm spacer rings to dial it in.\u003c\/p\u003e\n\u003ch3\u003eInline Filter Thread\u003c\/h3\u003e\n\u003cp\u003eThe top section of the flattener body unscrews, exposing a 2\" filter thread on the lower section. Thread in a light pollution, UHC, or narrowband filter without adding a separate filter drawer or filter wheel. For one-shot color camera setups with a single broadband or dual-narrowband filter, this keeps the imaging train short and the back focus math simple.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1× dedicated field flattener — no focal reduction.\u003c\/strong\u003e Maintains the AT80EDT's native 480mm f\/6. Flattens the field for round stars across your sensor without changing image scale or field of view.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExcellent APS-C coverage.\u003c\/strong\u003e Corrects field curvature across APS-C (roughly 22×15mm) sensors and smaller with round stars from center to edge. Full-frame sensors may show some residual curvature at the extreme corners.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptically matched to the AT80EDT.\u003c\/strong\u003e Designed for the AT80EDT's specific focal length and field curvature. Delivers better correction than generic flatteners because the optics are tuned to this scope.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM63 threaded scope-side connection.\u003c\/strong\u003e Threads directly to the AT80EDT focuser drawtube or Camera Angle Adjuster. No barrel insert, no adapter — secure, tilt-free positioning every session.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48mm T-thread camera connection.\u003c\/strong\u003e DSLR and mirrorless bodies connect via a T-ring (sold separately); dedicated CMOS\/CCD astronomy cameras attach directly — 48mm T-threads are standard on most.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e55mm back focus.\u003c\/strong\u003e From the flattener shoulder to the sensor. Standard DSLR T-ring spacing typically hits this naturally. ZWO filter wheel + OAG + camera stacks are designed for 55mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2\" inline filter thread.\u003c\/strong\u003e Unscrew the top section to expose a 2\" filter thread for inline filter use without a filter drawer.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully multi-coated optics.\u003c\/strong\u003e Maximizes light transmission and minimizes internal reflections.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLightweight at 9.5 oz.\u003c\/strong\u003e Minimal impact on balance or focuser load.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProtective covers included.\u003c\/strong\u003e Threaded covers for both ends.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eObserving Tip\u003c\/h3\u003e\n\u003cp\u003eThe AT80EDT at 480mm f\/6 is a natural widefield imaging scope, and one of its strengths is that it frames larger targets well at a fast focal ratio. With the 1× flattener and an APS-C camera, you've got a flat, corrected field at 480mm — enough focal length for the Rosette Nebula, the Heart and Soul pair, the Lagoon and Trifid region, and similar mid-size targets to fill the frame with detail. If you're running a one-shot color camera with a single broadband or dual-narrowband filter, thread the filter into the flattener's 2\" thread and skip the filter drawer. Fewer connections, less tilt risk, simpler setup.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat's the difference between this and the 0.8× reducer\/flattener?\u003c\/strong\u003e\u003cbr\u003eThe AT80EDTFF is a 1× flattener — it corrects field curvature without changing focal length. You keep 480mm at f\/6. The 0.8× reducer\/flattener reduces to 384mm at f\/4.8 — faster exposures (56% more light per pixel), wider field, but different image scale. Choose the 1× for more image scale on smaller targets. Choose the 0.8× for wider fields and shorter exposures.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill this cover a full-frame sensor?\u003c\/strong\u003e\u003cbr\u003eThe flattener performs best with APS-C sensors and smaller. On full-frame chips, you may see some residual field curvature at the extreme corners. This is a function of the 80mm aperture — the corrected image circle is large enough for APS-C but reaches its limits on full frame. If you need guaranteed full-frame flat-field coverage, consider the AT115EDT or AT130EDT with their respective 1× flatteners.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDo I need a T-ring?\u003c\/strong\u003e\u003cbr\u003eIf you're using a DSLR or mirrorless camera, yes — you need a T-ring for your specific camera mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have 48mm T-threads built in and connect directly.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use a filter wheel with this?\u003c\/strong\u003e\u003cbr\u003eYes. A ZWO filter wheel + OAG + camera stack is designed to hit 55mm back focus. Thread the flattener onto the scope, attach the filter wheel to the 48mm T-threads, and the system is at the correct spacing.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow critical is the 55mm back focus?\u003c\/strong\u003e\u003cbr\u003eVery. If the spacing from the flattener's shoulder to your sensor is off by more than a couple of millimeters, you'll see elongated stars toward the edges. M48 spacer rings in 1mm, 2mm, and 5mm increments let you dial it in. Measure once, mark your configuration, and it stays consistent.\u003c\/p\u003e\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\u003cp\u003eThe AT80EDT is a compact, travel-friendly imaging refractor with a loyal following. The AT80EDTFF gives it a flat field at the full 480mm f\/6 — round stars from center to edge across APS-C sensors, no compromise on focal length or image scale. If you're imaging with the AT80EDT and an APS-C camera, this is the flattener that was matched to your scope. Thread it on, set the spacing, and shoot.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eModel\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT80EDTFF\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eOptical Function\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1× field flattener (no focal reduction)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Compatibility\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT80EDT\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFocal Length (with flattener)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e480mm (unchanged)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFocal Ratio (with flattener)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003ef\/6 (unchanged)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eSensor Coverage\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAPS-C (22×15mm) and smaller — full correction. Full frame may show residual corner curvature.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eM63 threaded (threads to focuser drawtube or Camera Angle Adjuster)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCamera Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e48mm T-threads\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBack Focus\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e55mm (flattener shoulder to sensor)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFilter Thread\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e2\" (accessible by unscrewing top section)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully multi-coated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e9.5 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eIncluded Accessories\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eThreaded covers for both ends\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":41598549459017,"sku":"AT80EDTFF","price":199.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/M631xFlattenerAT80EDT_1-10855.jpg?v=1738261631"},{"product_id":"astro-tech-1x-field-flattener-for-astro-tech-at115edt-triplet-apo-refractor","title":"Astro-Tech 1X Field Flattener For Astro-Tech AT115EDT Triplet APO Refractor","description":"\u003cp\u003eThe AT115EDT has become one of the most popular imaging refractors we sell — 115mm of FK-61 triplet glass at 805mm f\/7, enough aperture and focal length to frame mid-size deep-sky targets with real detail. But like any refractor at f\/7, the field curves. Stars in the center are sharp. Stars at the edges stretch. That's not a flaw in the scope — it's what a curved focal plane does to a flat sensor. And it's exactly what a dedicated field flattener is designed to fix.\u003c\/p\u003e\n\u003cp\u003eThe AT115EDTFF is a 1× flattener built specifically for the AT115EDT. It doesn't reduce the focal length or change the focal ratio — you keep the full 805mm at f\/7. What it does is flatten the field so stars are round and sharp from center to edge across your entire sensor, including full-frame chips. The AT115EDT delivers the light. The flattener makes sure that light lands correctly on every part of your sensor.\u003c\/p\u003e\n\u003ch3\u003eWhy 1× Instead of a Reducer?\u003c\/h3\u003e\n\u003cp\u003eThe AT115EDT has a strong following among imagers who value its 805mm focal length for the image scale it provides. At 805mm, mid-size targets — the Rosette Nebula, the Crab Nebula, galaxy pairs, the Veil complex — have enough scale to show structural detail without being too large to frame. A 0.8× reducer would drop that to 644mm and widen the field, which is great for larger targets but changes the image scale you bought the scope for. The 1× flattener preserves everything about the AT115EDT's native optical performance and just fixes the field curvature.\u003c\/p\u003e\n\u003ch3\u003eConnection and Installation\u003c\/h3\u003e\n\u003cp\u003eThe scope side of the AT115EDTFF has an M63 threaded connection that threads directly onto the AT115EDT focuser drawtube — or onto the Camera Angle Adjuster if you're using the rotation feature for framing. No barrel insert. No adapter between the flattener and the focuser. Just threads — secure, repeatable, and square to the optical axis every session.\u003c\/p\u003e\n\u003cp\u003eThe camera side terminates in 48mm T-threads. DSLR and mirrorless bodies connect via a T-ring for your specific camera mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have 48mm T-threads built in and connect directly without a T-ring.\u003c\/p\u003e\n\u003cp\u003eBack focus is 55mm from the flattener's shoulder to the sensor. ZWO filter wheel + OAG + camera stacks are designed for 55mm and bolt together directly. A DSLR with a standard T-ring typically hits the spacing naturally. Dedicated cameras with different flange distances may need 48mm spacer rings to fine-tune.\u003c\/p\u003e\n\u003ch3\u003eInline Filter Thread\u003c\/h3\u003e\n\u003cp\u003eThe top section of the flattener body unscrews, exposing a 2\" filter thread on the lower section. Thread in a light pollution, UHC, or narrowband filter without a separate filter drawer or filter wheel. For one-shot color camera setups with a single broadband filter, this keeps the imaging train short and the back focus math simple.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1× dedicated field flattener — no focal reduction.\u003c\/strong\u003e Maintains the AT115EDT's native 805mm f\/7. Flattens the field for round stars from center to edge without changing image scale or field of view.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull-frame sensor coverage.\u003c\/strong\u003e Corrects field curvature across full-frame (36×24mm) sensors and smaller. Round stars in the corners, not just the center.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptically matched to the AT115EDT.\u003c\/strong\u003e Designed for the AT115EDT's specific focal length and field curvature. Delivers better edge correction than generic flatteners because the optical correction is tuned to this scope.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM63 threaded scope-side connection.\u003c\/strong\u003e Threads directly to the AT115EDT focuser drawtube or Camera Angle Adjuster. No barrel insert, no adapter — secure, tilt-free positioning every session.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48mm T-thread camera connection.\u003c\/strong\u003e DSLR and mirrorless bodies connect via a T-ring (sold separately); dedicated CMOS\/CCD astronomy cameras attach directly — 48mm T-threads are standard on most.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e55mm back focus.\u003c\/strong\u003e From the flattener shoulder to the sensor. Standard DSLR T-ring spacing typically hits this naturally. ZWO filter wheel + OAG + camera stacks are designed for 55mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2\" inline filter thread.\u003c\/strong\u003e Unscrew the top section to expose a 2\" filter thread for inline filter use without a filter drawer.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully multi-coated optics.\u003c\/strong\u003e Maximizes light transmission and minimizes internal reflections.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLightweight at 9.5 oz.\u003c\/strong\u003e Minimal impact on balance or focuser load.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProtective covers included.\u003c\/strong\u003e Thread on covers for both ends.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eObserving Tip\u003c\/h3\u003e\n\u003cp\u003eThe AT115EDT at 805mm f\/7 with the 1× flattener is a versatile imaging platform — long enough for galaxy detail and planetary nebula structure, wide enough for mid-size emission nebulae. If you're running a one-shot color camera with a dual-narrowband filter, thread the filter into the flattener's 2\" filter thread and skip the filter drawer entirely. Fewer connections mean less chance of tilt, less back focus to calculate, and a stiffer imaging train. Simpler is usually better.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat's the difference between this and a 0.8× reducer\/flattener?\u003c\/strong\u003e\u003cbr\u003eThe AT115EDTFF is a 1× flattener — it corrects field curvature without changing focal length. You keep 805mm at f\/7. A 0.8× reducer\/flattener would both flatten the field and reduce to ~644mm at ~f\/5.6 — faster exposures, wider field, but different image scale. Choose the 1× for full-resolution work on smaller targets. Choose the 0.8× for wider fields and shorter exposures.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill this work with other AT scopes?\u003c\/strong\u003e\u003cbr\u003eIt's designed for the AT115EDT. The optical correction is matched to the AT115EDT's specific focal length and field curvature. It may work with other refractors that use a 2\" focuser, but performance with other scopes is not guaranteed.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes this cover a full-frame sensor?\u003c\/strong\u003e\u003cbr\u003eYes. The corrected image circle covers full-frame 36×24mm sensors with flat, round stars from center to edge. Owners have confirmed flat fields on APS-C sensors with filter wheel and OAG stacks.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow does the M63 thread connection work?\u003c\/strong\u003e\u003cbr\u003eThe AT115EDT focuser drawtube has M63 threads on its back end. Remove the 2\" visual adapter and the flattener threads directly onto those exposed threads. If you're using the Camera Angle Adjuster, the flattener threads onto the adjuster instead. Either way, it's a direct threaded connection — no barrel, no adapter, no chance of tilt.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use a filter wheel with this?\u003c\/strong\u003e\u003cbr\u003eYes. A ZWO filter wheel + OAG + camera stack is designed to hit 55mm back focus. Thread the flattener onto the scope, attach the filter wheel to the 48mm T-threads, and the system is at the correct spacing.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow critical is the 55mm back focus?\u003c\/strong\u003e\u003cbr\u003eVery. If the spacing from the flattener's shoulder to your sensor is off by more than a couple of millimeters, you'll see elongated stars toward the edges. M48 spacer rings in 1mm, 2mm, and 5mm increments let you dial it in precisely.\u003c\/p\u003e\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\u003cp\u003eThe AT115EDT is already one of the best values in triplet imaging refractors. The AT115EDTFF turns it into a flat-field imaging system at the full 805mm f\/7 — round stars from center to corners, full-frame coverage, and no compromise on focal length or image scale. If you're imaging with the AT115EDT and want flat fields without reducing, this is the flattener that was matched to your scope.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eModel\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT115EDTFF\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eOptical Function\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1× field flattener (no focal reduction)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Compatibility\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT115EDT\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFocal Length (with flattener)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e805mm (unchanged)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFocal Ratio (with flattener)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003ef\/7 (unchanged)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eSensor Coverage\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFull frame (36×24mm) and smaller\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eM63 threaded (threads to focuser drawtube or Camera Angle Adjuster)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCamera Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e48mm T-threads\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBack Focus\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e55mm (flattener shoulder to sensor)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFilter Thread\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e2\" (accessible by unscrewing top section)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully multi-coated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e9.5 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eIncluded Accessories\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eThreaded covers for both ends\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":41598561091657,"sku":"AT115EDTFF","price":199.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/M631xFlattenerAT115EDT_1-10840.jpg?v=1738261689"},{"product_id":"astro-tech-1x-field-flattener-for-astro-tech-at130edt-triplet-apo-refractor","title":"Astro-Tech 1X Field Flattener For Astro-Tech AT130EDT Triplet APO Refractor","description":"\u003cp\u003eThe AT130EDT is one of the more capable imaging refractors in our lineup — 130mm of FK-61 triplet glass at 910mm f\/7, sharp enough to resolve detail that smaller scopes can't touch. But at f\/7, the field curves. Stars in the center are pinpoints. Stars at the edges start to elongate and blur. The scope isn't doing anything wrong — every uncorrected refractor does this. A flat sensor and a curved focal plane simply don't agree, and the longer the focal length, the more obvious the disagreement becomes.\u003c\/p\u003e\n\u003cp\u003eThe AT130EDTFF is a dedicated 1× field flattener that corrects this without changing anything else about the optical system. You keep the full 910mm focal length. You keep f\/7. You keep the image scale you chose this scope for. What changes is the field — it goes flat. Stars are round from center to edge across full-frame sensors. The optics the AT130EDT was designed to deliver now reach every corner of your chip.\u003c\/p\u003e\n\u003ch3\u003eWhy 1× Instead of a Reducer?\u003c\/h3\u003e\n\u003cp\u003eWe also make a 0.8× reducer\/field flattener for the AT130EDT. That drops the focal length to 728mm at f\/5.6 — faster exposures, wider field, but a different image scale. The 1× flattener is for imagers who specifically chose the AT130EDT for its 910mm focal length and don't want to give it up. If you're shooting smaller targets — planetary nebulae, galaxy details, tight emission structures — the full 910mm gives you the resolution and image scale to frame them properly. The flattener makes sure the field is flat while you use it.\u003c\/p\u003e\n\u003ch3\u003eConnection and Installation\u003c\/h3\u003e\n\u003cp\u003eThe scope side of the AT130EDTFF has an M63 threaded connection that threads directly onto the AT130EDT focuser drawtube — or onto the Camera Angle Adjuster if you're using the rotation feature. No barrel insert. No adapter. Just threads — secure, repeatable, and square to the optical axis every time you set up.\u003c\/p\u003e\n\u003cp\u003eThe camera side terminates in 48mm T-threads. DSLR and mirrorless bodies connect via a T-ring for your specific camera mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have 48mm T-threads built in and connect directly without a T-ring.\u003c\/p\u003e\n\u003cp\u003eBack focus is 55mm from the flattener's shoulder to the sensor. ZWO filter wheel + OAG + camera stacks are designed for 55mm and bolt together directly. A DSLR with a standard T-ring typically hits the spacing naturally. Dedicated cameras with different flange distances may need 48mm spacer rings to dial it in.\u003c\/p\u003e\n\u003ch3\u003eInline Filter Thread\u003c\/h3\u003e\n\u003cp\u003eThe top section of the flattener body unscrews, exposing a 2\" filter thread on the lower section. Thread in a light pollution, UHC, or narrowband filter without adding a separate filter drawer or filter wheel. For one-shot color camera setups with a single broadband or dual-narrowband filter, this keeps the imaging train short and the back focus math simple.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1× dedicated field flattener — no focal reduction.\u003c\/strong\u003e Maintains the AT130EDT's native 910mm f\/7. Flattens the field for round stars from center to edge without changing image scale or field of view.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull-frame sensor coverage.\u003c\/strong\u003e Corrects field curvature across full-frame (36×24mm) sensors and smaller. Round stars in the corners, not just the center.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptically matched to the AT130EDT.\u003c\/strong\u003e Designed for the AT130EDT's specific focal length and field curvature. Delivers better edge correction than generic flatteners because the optical correction is tuned to this scope.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM63 threaded scope-side connection.\u003c\/strong\u003e Threads directly to the AT130EDT focuser drawtube or Camera Angle Adjuster. No barrel insert, no adapter — secure, tilt-free positioning every session.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48mm T-thread camera connection.\u003c\/strong\u003e DSLR and mirrorless bodies connect via a T-ring (sold separately); dedicated CMOS\/CCD astronomy cameras attach directly — 48mm T-threads are standard on most.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e55mm back focus.\u003c\/strong\u003e From the flattener shoulder to the sensor. Standard DSLR T-ring spacing typically hits this naturally. ZWO filter wheel + OAG + camera stacks are designed for 55mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2\" inline filter thread.\u003c\/strong\u003e Unscrew the top section to expose a 2\" filter thread for inline filter use without a filter drawer.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully multi-coated optics.\u003c\/strong\u003e Maximizes light transmission and minimizes internal reflections.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLightweight at 9.5 oz.\u003c\/strong\u003e Minimal impact on balance or focuser load.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProtective covers included.\u003c\/strong\u003e Slip-on rubber covers for both ends.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eObserving Tip\u003c\/h3\u003e\n\u003cp\u003eAt 910mm, the AT130EDT with the 1× flattener is a natural match for smaller deep-sky targets — planetary nebulae like M57, M27, and NGC 7662 fill the frame beautifully at this focal length. Galaxy groups like the Leo Triplet or Markarian's Chain get enough image scale to show detail without being too tight to frame. If you find yourself cropping every image you take with the 0.8× reducer because the target is too small in the frame, the 1× flattener gives you the image scale you actually want — and the flat field to use it properly.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat's the difference between this and the 0.8× reducer\/flattener?\u003c\/strong\u003e\u003cbr\u003eThe AT130EDTFF is a 1× flattener — it corrects field curvature without changing focal length. You keep 910mm at f\/7. The 0.8× reducer\/flattener reduces to 728mm at f\/5.6 — faster exposures (56% more light per pixel), wider field, but different image scale. Choose the 1× for full-resolution imaging of smaller targets. Choose the 0.8× for wider fields and shorter exposures.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes this cover a full-frame sensor?\u003c\/strong\u003e\u003cbr\u003eYes. The corrected image circle covers full-frame 36×24mm sensors with flat, round stars from center to edge.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDo I need a T-ring?\u003c\/strong\u003e\u003cbr\u003eIf you're using a DSLR or mirrorless camera, yes — you need a T-ring for your specific camera mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have 48mm T-threads built in and connect directly.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use a filter wheel with this?\u003c\/strong\u003e\u003cbr\u003eYes. A ZWO filter wheel + OAG + camera stack is designed to hit 55mm back focus. Thread the flattener onto the scope, attach the filter wheel to the 48mm T-threads, and the system is at the correct spacing.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow critical is the 55mm back focus?\u003c\/strong\u003e\u003cbr\u003eVery. If the spacing from the flattener's shoulder to your sensor is off by more than a couple of millimeters, you'll see elongated stars toward the edges. M48 spacer rings in 1mm, 2mm, and 5mm increments let you dial it in. Measure once, mark your configuration, and it stays consistent.\u003c\/p\u003e\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\u003cp\u003eThe AT130EDT at 910mm f\/7 has the focal length and resolution to frame smaller targets with real detail. The AT130EDTFF makes sure that resolution reaches every corner of your sensor. It threads on, stays square, flattens the field across full frame, and doesn't change your image scale. If you're imaging with the AT130EDT and you want flat fields at the full 910mm, this is the flattener that was designed for the job.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eModel\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT130EDTFF\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eOptical Function\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1× field flattener (no focal reduction)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Compatibility\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT130EDT\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFocal Length (with flattener)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e910mm (unchanged)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFocal Ratio (with flattener)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003ef\/7 (unchanged)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eSensor Coverage\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFull frame (36×24mm) and smaller\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eM63 threaded (threads to focuser drawtube or Camera Angle Adjuster)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCamera Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e48mm T-threads\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBack Focus\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e55mm (flattener shoulder to sensor)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFilter Thread\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e2\" (accessible by unscrewing top section)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully multi-coated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e9.5 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eIncluded Accessories\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eSlip-on rubber covers for both ends\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":41598562304073,"sku":"AT130EDTFF","price":199.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/M631xFlattenerAT130EDT_1-10833.jpg?v=1738261730"},{"product_id":"astro-tech-1x-field-flattener-for-astro-tech-at90-triplet-apo-refractor","title":"Astro-Tech 1X Field Flattener For Astro-Tech AT90 Triplet APO Refractor","description":"\u003cp\u003eThe AT90EDX and AT90CFT are triplet APO refractors with essentially perfect on-axis optics — guaranteed .95 Strehl or higher. But point a camera at them without correction and the field curves. Stars in the center are sharp. Stars at the edges are not. The scope didn't do anything wrong — a flat sensor and a curved focal plane just don't agree. That's where a field flattener earns its place in the imaging train.\u003c\/p\u003e\n\u003cp\u003eThe AT90FF is a dedicated 1× flattener for the AT90 triplet series. It doesn't reduce the focal length or change the focal ratio — you keep the full 540mm at f\/6. What it does is flatten the field across the sensor so stars are round and sharp from center to edge, all the way to the corners of a full-frame chip. The AT90EDX delivers clean, color-free optics. The AT90FF delivers that quality across your entire sensor.\u003c\/p\u003e\n\u003ch3\u003eDedicated — Not Generic\u003c\/h3\u003e\n\u003cp\u003eThis flattener is optically matched to the AT90EDX and AT90CFT's specific focal length and field curvature. A generic 1× flattener designed for f\/5–f\/7 refractors in general will sort-of work, but it won't deliver the same edge-to-edge correction as a flattener that knows the exact optical system it's sitting behind. One reviewer put it simply: the images with the dedicated flattener were \"superb across the entire field,\" compared to \"okay\" with a generic unit. The difference is the matching.\u003c\/p\u003e\n\u003ch3\u003eConnection and Installation\u003c\/h3\u003e\n\u003cp\u003eThe scope side of the AT90FF has an M63 threaded connection that threads directly onto the AT90EDX or AT90CFT focuser drawtube — or onto the Camera Angle Adjuster if you're using the rotation feature for framing. No adapters between the flattener and the focuser. No barrel insert that can introduce tilt. Just threads — secure, repeatable, and square to the optical axis every time.\u003c\/p\u003e\n\u003cp\u003eThe camera side terminates in 48mm T-threads. DSLR and mirrorless bodies connect via a T-ring for your specific camera mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have 48mm T-threads built in and connect directly without a T-ring.\u003c\/p\u003e\n\u003cp\u003eBack focus is 55mm from the flattener's shoulder to the sensor. If you're using a ZWO camera with a ZWO filter wheel and off-axis guider, the ZWO system is designed so the combined stack hits 55mm automatically — just bolt the pieces together. A DSLR with a standard T-ring typically hits the spacing naturally. If you need to fine-tune, 48mm spacer rings in 1mm, 2mm, and 5mm increments let you dial it in precisely.\u003c\/p\u003e\n\u003ch3\u003eInline Filter Thread\u003c\/h3\u003e\n\u003cp\u003eThe top section of the flattener body unscrews from the main housing, exposing a 2\" filter thread on the lower section. This lets you thread a 2\" light pollution, UHC, or narrowband filter directly into the imaging train — inline, without a separate filter drawer or filter wheel adding back focus and potential tilt. If you're shooting from a light-polluted site with a one-shot color camera and a single broadband filter, this is a clean, simple way to get the filter into the path.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1× dedicated field flattener — no focal reduction.\u003c\/strong\u003e Maintains the AT90's native 540mm focal length and f\/6 focal ratio. Flattens the field for round stars from center to edge without changing your image scale or field of view.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull-frame sensor coverage.\u003c\/strong\u003e Corrects field curvature across full-frame (36×24mm) sensors and smaller. No vignetting on APS-C or full-frame chips. Stars are round in the corners, not just the center.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptically matched to the AT90EDX and AT90CFT.\u003c\/strong\u003e Designed for the specific focal length and field curvature of the 90mm f\/6 triplet. Delivers better edge correction than generic flatteners because it's tuned to this optical system.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM63 threaded scope-side connection.\u003c\/strong\u003e Threads directly to the AT90 focuser drawtube or Camera Angle Adjuster. No barrel insert, no adapter — repeatable, tilt-free positioning every session.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48mm T-thread camera connection.\u003c\/strong\u003e DSLR and mirrorless bodies connect via a T-ring (sold separately); dedicated CMOS\/CCD astronomy cameras attach directly — 48mm T-threads are standard on most.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e55mm back focus.\u003c\/strong\u003e From the flattener shoulder to the sensor. Standard DSLR T-ring spacing typically hits this naturally. ZWO filter wheel + OAG + camera stacks are designed for 55mm and bolt together directly.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2\" inline filter thread.\u003c\/strong\u003e Unscrew the top section to expose a 2\" filter thread. Thread in a light pollution or narrowband filter without adding a filter drawer to your imaging train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully multi-coated optics.\u003c\/strong\u003e Maximizes light transmission and minimizes internal reflections for cleaner images.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLightweight at 9.5 oz.\u003c\/strong\u003e Minimal impact on balance. Won't overload the focuser or shift your imaging train's center of gravity.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProtective covers included.\u003c\/strong\u003e Slip-on rubber covers for both the 48mm T-thread end and the M63 scope-side threads.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eObserving Tip\u003c\/h3\u003e\n\u003cp\u003eIf you're switching from a DSLR to a dedicated astronomy camera, the back focus math changes even though the target is the same 55mm. A DSLR T-ring has a built-in flange distance that gets you close to 55mm with just the ring. A ZWO or QHY camera body is much shorter — which is why they're designed to stack with a filter wheel, off-axis guider, or spacer rings to make up the distance. Measure the sensor-to-flange distance of your camera (it's in the specs), subtract from 55mm, and fill the gap with spacers or accessories. Get this right once and mark your configuration — it stays right forever.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat's the difference between this and the 0.8× reducer\/flattener?\u003c\/strong\u003e\u003cbr\u003eThe AT90FF is a 1× flattener — it corrects field curvature without changing the focal length. You keep the full 540mm at f\/6. The 0.8× reducer\/flattener both flattens the field and reduces the focal length to 432mm at f\/4.8 — faster exposures, wider field, but different image scale. If you want to preserve the native focal length and image scale of the AT90, use the 1× flattener. If you want faster, wider imaging, use the 0.8× reducer.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes this cover a full-frame sensor?\u003c\/strong\u003e\u003cbr\u003eYes. The corrected image circle covers full-frame 36×24mm sensors. Owners have confirmed flat fields with no vignetting on the ASI2600MC Pro (APS-C sized sensor) and similar cameras, and the product description specifies full-frame coverage.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow does the M63 thread connection work?\u003c\/strong\u003e\u003cbr\u003eThe AT90EDX and AT90CFT focuser drawtube has M63 threads on its back end. You remove the 2\" visual adapter, and the flattener threads directly onto those exposed threads. If you're using the Camera Angle Adjuster, the flattener threads onto the adjuster instead. Either way, it's a direct threaded connection — no barrel, no adapter, no chance of tilt from a loose fit.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use a filter wheel with this?\u003c\/strong\u003e\u003cbr\u003eYes. A ZWO filter wheel plus off-axis guider plus camera stack is designed to hit 55mm back focus automatically. Thread the flattener onto the scope, attach the filter wheel to the 48mm T-threads, and the system is at the correct spacing. One CN owner runs an ASI294 + ZWO filter wheel + ZWO OAG on the same flattener without issues.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow critical is the 55mm back focus?\u003c\/strong\u003e\u003cbr\u003eVery. If the spacing from the flattener's shoulder to your sensor is off by more than a couple of millimeters, you'll see elongated stars toward the edges of the frame. M48 spacer rings in 1mm, 2mm, and 5mm increments let you dial it in. Measure once, mark your configuration, and it stays consistent.\u003c\/p\u003e\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\u003cp\u003eYou bought the AT90EDX or AT90CFT because the optics are exceptional. The AT90FF makes sure those optics translate to your sensor — all of your sensor, not just the center. It threads on, it stays square, it flattens the field from center to corners on a full-frame chip, and it doesn't change your focal length or focal ratio. If you're imaging with an AT90 and you want flat fields at the native 540mm f\/6, this is the flattener that was designed for the job.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eModel\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT90FF\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eOptical Function\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1× field flattener (no focal reduction)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Compatibility\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT90EDX and AT90CFT\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFocal Length (with flattener)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e540mm (unchanged)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFocal Ratio (with flattener)\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003ef\/6 (unchanged)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eSensor Coverage\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFull frame (36×24mm) and smaller\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eM63 threaded (threads to focuser drawtube or Camera Angle Adjuster)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCamera Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e48mm T-threads\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBack Focus\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e55mm (flattener shoulder to sensor)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eFilter Thread\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e2\" (accessible by unscrewing top section)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully multi-coated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e9.5 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eIncluded Accessories\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eThreaded covers for both ends\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":41598563778633,"sku":"AT90FF","price":199.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/M631xFlattenerAT90EDX_1-10849.jpg?v=1738261662"},{"product_id":"astro-tech-0-8x-reducer-for-astro-tech-edq-series-86-106-126","title":"Astro-Tech 0.8X Reducer For Astro-Tech EDQ Series 86\/106\/126","description":"\u003cp\u003eThe EDQ series scopes are designed with imaging in mind. The quad-element optical system builds field correction right into the telescope — no separate flattener needed. Stars are round from center to corners straight out of the focuser, across sensors up to full frame. That's what makes the EDQ line different from conventional doublets and triplets, and it's what makes this reducer different from every other 0.8× reducer we sell.\u003c\/p\u003e\n\u003cp\u003eThe ATEDQR doesn't need to flatten the field — the scope already does that. Its only job is to speed the system up. It takes the EDQ's native f\/7 and brings it down to f\/5.6 — a 56% increase in light-gathering speed per pixel — while preserving the flat, corrected field the scope was designed to deliver. Shorter exposures, more signal per frame, wider field of view, and the same sharp, round stars from center to edge that you bought the EDQ for in the first place.\u003c\/p\u003e\n\u003ch3\u003eOne Reducer, Three Scopes\u003c\/h3\u003e\n\u003cp\u003eThe ATEDQR is optically designed to work with all three EDQ refractors:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAT86EDQ:\u003c\/strong\u003e 602mm f\/7 → 482mm f\/5.6\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAT106EDQ:\u003c\/strong\u003e 742mm f\/7 → 594mm f\/5.6\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAT126EDQ:\u003c\/strong\u003e 882mm f\/7 → 706mm f\/5.6\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eAll three scopes share the same back-end thread geometry, so one reducer works across the entire EDQ line. If you own more than one EDQ scope, you only need one reducer.\u003c\/p\u003e\n\u003ch3\u003eFull-Frame Coverage\u003c\/h3\u003e\n\u003cp\u003eThis is where the ATEDQR differs from the dedicated reducers we sell for the AT80ED and AT102ED. Those reducers are designed for APS-C sensors and smaller — the image circle doesn't cover a full-frame chip. The ATEDQR covers full frame. Because the EDQ's built-in flattener already corrects the field across a large image circle, the reducer maintains that correction at the faster focal ratio. Stars stay round all the way to the corners of a full-frame DSLR or a large-format CMOS camera like the ASI2600MC.\u003c\/p\u003e\n\u003ch3\u003eConnection and Installation\u003c\/h3\u003e\n\u003cp\u003eThe reducer threads directly onto the EDQ scope after you remove the visual adapter from the focuser back end. You then attach part of the photographic extension tube that ships with the scope — the upper section threads onto the reducer and provides the 48mm T-thread connection for your camera. The product manual (included, and available as a PDF download on this page) walks through the steps with photos.\u003c\/p\u003e\n\u003cp\u003eBack focus is 55mm from the reducer's shoulder to the sensor. Most DSLR setups with a standard T-ring hit this spacing naturally. Dedicated CMOS astronomy cameras may need spacer rings to fine-tune — and it's worth getting right. The flat field the EDQ delivers is only as good as your spacing. Off by a few millimeters and the corners show it.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e0.8× optical reduction for all three EDQ scopes.\u003c\/strong\u003e Works with the AT86EDQ, AT106EDQ, and AT126EDQ. Reduces f\/7 to f\/5.6 — 56% more light per pixel, shorter exposures, wider field of view.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull-frame sensor coverage.\u003c\/strong\u003e The EDQ's built-in field correction means the reducer maintains flat, corrected fields across full-frame chips — not just APS-C. Stars are round from center to corners on sensors up to 36×24mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePreserves the EDQ's flat field.\u003c\/strong\u003e The quad-element optical design already corrects field curvature. The reducer speeds the system up without compromising the flat field you paid for.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e48mm T-thread camera connection.\u003c\/strong\u003e DSLR and mirrorless bodies connect via a T-ring (sold separately); dedicated CMOS\/CCD astronomy cameras attach directly — 48mm T-threads are standard on most.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e55mm back focus.\u003c\/strong\u003e From the reducer shoulder to the sensor. Standard DSLR T-ring spacing typically hits this naturally. Dedicated cameras may need spacing adjustment with M48 spacer rings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThreaded scope-side connection.\u003c\/strong\u003e Threads onto the EDQ focuser back end after removing the visual adapter. Secure, repeatable positioning with no play or tilt.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully multi-coated optics.\u003c\/strong\u003e Maximizes light transmission and minimizes internal reflections for cleaner, higher-contrast images.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLightweight at 8 oz.\u003c\/strong\u003e Minimal impact on balance — won't shift your imaging train's center of gravity significantly.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProtective covers included.\u003c\/strong\u003e Slip-on rubber covers for both the 48mm T-thread end and the scope-side barrel.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eObserving Tip\u003c\/h3\u003e\n\u003cp\u003eIf you're shooting with the AT86EDQ at f\/5.6, the wider field of view opens up targets that were hard to frame at f\/7 — the Veil Nebula complex, the North America and Pelican pair, or M31 with its companion galaxies. The shorter focal length also means shorter exposures, which is forgiving on mounts that aren't perfectly guided. If your mount tracks well at 120-second subs at f\/7, it'll track well at 90-second subs at f\/5.6 — and you'll get more signal per frame.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWill this work with non-EDQ Astro-Tech scopes?\u003c\/strong\u003e\u003cbr\u003eNo. The ATEDQR is designed specifically for the EDQ series and threads onto the EDQ focuser back end. It will not fit the AT80ED, AT102ED, AT115EDT, AT130EDT, or any other AT scope. Those scopes have their own dedicated reducers and flatteners.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes this replace the field flattener in the EDQ?\u003c\/strong\u003e\u003cbr\u003eNo — the EDQ's built-in field flattener remains in the optical path. The reducer works in addition to it, not instead of it. The built-in flattener handles field correction; the reducer handles focal reduction. Together they deliver a flat, fast f\/5.6 system.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow do I attach this to the scope?\u003c\/strong\u003e\u003cbr\u003eRemove the visual adapter from the focuser back end. Thread the reducer onto the exposed threads. Then attach the upper section of the photographic extension tube (included with the scope) to the reducer. This provides the 48mm T-thread connection for your camera. The included product manual has step-by-step photos. If you have questions, call us — we've walked customers through this before.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes this cover a full-frame sensor?\u003c\/strong\u003e\u003cbr\u003eYes. Unlike the AT80EDRF and AT102EDRF (which are APS-C only), the ATEDQR covers full-frame sensors. The EDQ's built-in field correction provides a large enough corrected image circle to maintain sharp stars across a 36×24mm chip at f\/5.6.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat cameras work well with this?\u003c\/strong\u003e\u003cbr\u003eAny camera that connects via 48mm T-threads — full-frame DSLRs (Canon EOS, Nikon FX, Sony full frame), APS-C DSLRs, and dedicated CMOS\/CCD astronomy cameras. The ZWO ASI2600MC, ASI533MC, ASI294MC, and similar cameras are all excellent matches. DSLR and mirrorless bodies require a T-ring for your specific mount (sold separately).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow critical is the 55mm back focus?\u003c\/strong\u003e\u003cbr\u003eVery. If the spacing from the reducer's shoulder to your sensor is off by more than a couple of millimeters, you'll see elongated stars toward the edges — even with the EDQ's flat field. M48 spacer rings in 1mm, 2mm, and 5mm increments let you dial it in. Measure once, mark your configuration, and it stays consistent.\u003c\/p\u003e\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\u003cp\u003eThe EDQ scopes are already flat-field imaging refractors. The ATEDQR makes them faster ones. It drops every scope in the series from f\/7 to f\/5.6, opens up the field of view, and cuts your exposure times — while preserving the flat, corrected field that makes the EDQ design worth owning. If you're imaging with an AT86EDQ, AT106EDQ, or AT126EDQ and you want to work faster without sacrificing what makes these scopes special, this is the reducer that was designed for the job.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eModel\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech ATEDQR\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eOptical Reduction\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e0.8×\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Compatibility\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT86EDQ, AT106EDQ, AT126EDQ\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eResulting Focal Ratio\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003ef\/5.6 (from f\/7 native)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eReduced Focal Lengths\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAT86EDQ: 482mm | AT106EDQ: 594mm | AT126EDQ: 706mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eSensor Coverage\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFull frame (36×24mm) and smaller\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eThreaded — threads onto EDQ focuser back end\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCamera Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e48mm T-threads (via photographic extension tube)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBack Focus\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e55mm (reducer shoulder to sensor)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully multi-coated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e8 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eIncluded Accessories\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eSlip-on rubber covers for both ends\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1 year\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":41600032047177,"sku":"ATEDQR","price":229.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/0.8xReducerEDQSeries_1-10868.jpg?v=1738261199"},{"product_id":"astro-tech-dedicated-0-8x-reducer-field-flattener-for-the-astro-tech-at102ed-refractor","title":"Astro-Tech Dedicated 0.8x Reducer\/Field Flattener for the Astro-Tech AT102ED Refractor","description":"\u003cp\u003eThe AT102ED is one of the better values in 4-inch refractors — 102mm of ED glass at f\/7, sharp enough for serious visual work and big enough to pull in detail that smaller scopes can't. But at 713mm and f\/7, astrophotography asks you to be patient. Exposures run long. The field curves at the edges. Stars that looked fine at the eyepiece turn into little streaks in the corners of your camera frame. A flat sensor and a curved focal plane were never going to agree on their own.\u003c\/p\u003e\n\n\u003cp\u003eThe AT102EDRF brings them together. It reduces the focal length to 571mm and the focal ratio to f\/5.6 — a 56% increase in light-gathering speed per pixel — while flattening the field across APS-C and smaller sensors. Stars stay round from center to edge. Exposures get shorter. And the wider field of view opens up targets that were too large to frame at 713mm — galaxy groups, sprawling nebulae, wide star fields in the Milky Way.\u003c\/p\u003e\n\n\u003ch3\u003eBuilt for This Scope\u003c\/h3\u003e\n\n\u003cp\u003eThis is not a generic 0.8× reducer that sort-of-works across a range of telescopes. The AT102EDRF is optically matched to the AT102ED's focal length and field curvature — specifically the 2017 model year and newer. That matching is what allows it to deliver flat, corrected fields rather than the compromised results you get from universal reducers that don't know what scope they're sitting behind.\u003c\/p\u003e\n\n\u003cp\u003eThe 2\" barrel slides directly into the AT102ED's focuser. No adapters between the reducer and the focuser — just insert, secure, and you're ready to image. The barrel includes internal 2\" filter threads, so a light pollution filter, UHC, or narrowband filter threads right in without a separate filter drawer.\u003c\/p\u003e\n\n\u003ch3\u003eCamera Connection\u003c\/h3\u003e\n\n\u003cp\u003eThe camera side terminates in M42×0.75 T-threads. DSLR and mirrorless bodies connect via a T-ring for your specific camera mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have M42 T-threads built in and connect directly without a T-ring.\u003c\/p\u003e\n\n\u003cp\u003eBack focus is 55mm from the reducer's shoulder to the sensor. Most DSLR T-ring setups hit this spacing naturally. Dedicated astro cameras may need spacer rings to fine-tune the distance. Getting back focus right is the single biggest factor in whether your corner stars come out round or stretched — it's worth measuring once and getting it dialed in.\u003c\/p\u003e\n\n\u003ch3\u003eSensor Coverage\u003c\/h3\u003e\n\n\u003cp\u003eThe AT102EDRF is designed for APS-C sensors and smaller. On APS-C chips — Canon Rebel\/EOS, Nikon DX, Sony APS-C — the corrected field is clean from center to edge. Dedicated astronomy cameras with sensors up to about 16mm diagonal work well. On a full-frame sensor, you'll see softening and possible vignetting in the corners. This is an honest limitation of the image circle at this price point, and it applies to most dedicated reducers in this class. If you're shooting full frame, you'll want a different optical path.\u003c\/p\u003e\n\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e0.8× dedicated optical reduction.\u003c\/strong\u003e Reduces the AT102ED from 713mm f\/7 to 571mm f\/5.6. That's 56% faster per pixel — shorter subs, more signal per frame, and a wider field of view for large targets.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eField flattening for APS-C and smaller sensors.\u003c\/strong\u003e Corrects native field curvature across the sensor so stars are round from center to corners. Designed for APS-C DSLRs, Micro Four Thirds, and dedicated CMOS astronomy cameras.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e2\" barrel insert.\u003c\/strong\u003e Slides directly into the AT102ED focuser. No threading adapters, no spacers between reducer and focuser. Clean, simple, repeatable positioning.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInternal 2\" filter thread.\u003c\/strong\u003e Thread a 2\" light pollution, UHC, or narrowband filter directly into the barrel. No separate filter drawer needed — keeps the imaging train short and the back focus calculation simple.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eM42×0.75 T-thread camera connection.\u003c\/strong\u003e DSLR and mirrorless bodies connect via a T-ring (sold separately); dedicated CMOS\/CCD astronomy cameras attach directly — M42 T-threads are standard on most.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e55mm back focus.\u003c\/strong\u003e From the reducer shoulder to the sensor. Standard DSLR T-ring spacing hits this naturally. Dedicated cameras may need M42 spacer rings to fine-tune.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFully multi-coated optics.\u003c\/strong\u003e Maximizes light transmission and reduces internal reflections for cleaner, higher-contrast images.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLightweight at 6.24 oz.\u003c\/strong\u003e Adds minimal weight to your imaging train — won't shift your balance point or strain the focuser.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eObserving Tip\u003c\/h3\u003e\n\n\u003cp\u003eIf you're shooting emission nebulae from light-polluted skies, thread a 2\" narrowband or dual-narrowband filter into the reducer barrel before inserting it into the focuser. At f\/5.6, narrowband filters perform well without the severe star halos you sometimes see at faster focal ratios. The internal filter thread means one less adapter in the chain, which means less opportunity for tilt or spacing error.\u003c\/p\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eWill this work with the AT102EDL?\u003c\/strong\u003e\u003cbr\u003e\nNo. The AT102EDL is a different optical design (FCD-100 glass, different focal length and curvature). It has its own dedicated 0.8× reducer\/flattener — the AT102EDLRF. Using the wrong reducer will produce poor results even if it physically fits.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDoes this fit AT102ED models made before 2017?\u003c\/strong\u003e\u003cbr\u003e\nIt's designed for the 2017 model year and newer. Older AT102ED versions had different focuser configurations that may not be compatible. If you're unsure which version you have, call us — we can help you confirm.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWill this work with a full-frame camera?\u003c\/strong\u003e\u003cbr\u003e\nIt will physically connect, but the corrected image circle doesn't cover a full-frame sensor. Expect softening and vignetting in the corners. This reducer is designed for APS-C and smaller sensors.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat cameras work well with this?\u003c\/strong\u003e\u003cbr\u003e\nAPS-C DSLRs (Canon Rebel\/EOS, Nikon DX), Micro Four Thirds, and dedicated CMOS astronomy cameras with sensors up to ~16mm diagonal. The ZWO ASI533MC, ASI294MC, and similar cameras are a natural match.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDo I need a T-ring?\u003c\/strong\u003e\u003cbr\u003e\nIf you're using a DSLR or mirrorless camera, yes — you need a T-ring for your specific camera mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have M42 T-threads built in and connect directly.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eHow critical is the 55mm back focus?\u003c\/strong\u003e\u003cbr\u003e\nVery. If the spacing from the reducer's shoulder to your sensor is off by more than a couple of millimeters, you'll see elongated stars toward the edges. M42 spacer rings in 1mm, 2mm, and 5mm increments let you dial it in precisely. Measure once, mark your configuration, and it stays consistent session to session.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eHow does this compare to the AT80EDRF?\u003c\/strong\u003e\u003cbr\u003e\nSame 0.8× reduction ratio and same basic design philosophy, but the AT102EDRF is optically matched to the AT102ED's longer focal length (713mm vs 560mm) and different field curvature. They are not interchangeable — each reducer is designed for its specific scope.\u003c\/p\u003e\n\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\n\u003cp\u003eThe AT102ED is a scope that a lot of people buy for visual and then start thinking about imaging. The AT102EDRF is what bridges that gap. It turns a 713mm f\/7 visual refractor into a 571mm f\/5.6 wide-field imaging system — faster, flatter, and wider — for a hundred dollars. It won't make a full-frame camera happy, but pair it with an APS-C DSLR or a dedicated astro camera, get the back focus right, and you have an imaging rig that punches well above its price class.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable style=\"width:100%; border-collapse: collapse;\"\u003e\n  \u003ctbody\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eModel\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT102EDRF\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eOptical Reduction\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e0.8×\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Compatibility\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT102ED (2017 model year and newer)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eOriginal Focal Length\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e713mm (AT102ED native)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eReduced Focal Length\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e571mm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eResulting Focal Ratio\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003ef\/5.6\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eSensor Coverage\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAPS-C and smaller (not full frame)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e2\" barrel insert with 2\" filter threads\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCamera Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eM42×0.75 T-threads\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBack Focus\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e55mm (reducer shoulder to sensor)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully multi-coated\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e6.24 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1 year limited\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":41639404306505,"sku":"AT102EDRF","price":99.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/image_aa692ee5-0654-41e0-ac5a-73d2b307819d.png?v=1722420391"},{"product_id":"astro-tech-dedicated-0-8x-reducer-field-flattener-for-the-astro-tech-at80ed","title":"Astro-Tech Dedicated 0.8x Reducer\/ Field Flattener for the Astro-Tech AT80ED","description":"\u003cp\u003eThe AT80ED is a sharp, portable 80mm ED doublet that punches above its weight visually. But when you point a camera at it, f\/7 starts to show its hand. Exposures take longer than you'd like. The field curves toward the edges. Stars that looked pinpoint at the eyepiece start bloating into little comets in the corners of your image. None of that is the scope's fault — it's just what an uncorrected optical path does to a flat sensor.\u003c\/p\u003e\n\n\u003cp\u003eThe AT80EDRF fixes both problems at once. It reduces the focal length from 560mm to 448mm, bringing the scope down to f\/5.6 — a 56% increase in light-gathering speed per pixel. And it flattens the field across the sensor, pulling those corner stars back into tight, round points. The result is a faster, wider, flat-field imaging system for under $90, designed specifically for this scope.\u003c\/p\u003e\n\n\u003ch3\u003eDedicated — Not Generic\u003c\/h3\u003e\n\n\u003cp\u003eThis reducer was designed to match the AT80ED's native focal length and field curvature. It isn't a universal 0.8× reducer that sort-of-works on multiple scopes — it's purpose-built for the AT80ED (2018 model year and newer). The optical correction is tuned to this specific scope, which means the stars it delivers are round across the field when the back focus is set correctly. Generic reducers can get you close. Dedicated reducers get you there.\u003c\/p\u003e\n\n\u003ch3\u003eSensor Coverage\u003c\/h3\u003e\n\n\u003cp\u003eThe AT80EDRF is designed for APS-C sensors and smaller. On an APS-C chip, the corrected field is clean edge to edge — no vignetting, round stars all the way to the corners. Dedicated CMOS astronomy cameras with sensors up to about 16mm diagonal (like the ZWO ASI533MC or ASI294MC) fit comfortably inside the corrected circle. On a full-frame sensor, you will see vignetting in the outer third of the frame. This is not a full-frame reducer — the copy is honest about that, and you should factor it into your camera choice.\u003c\/p\u003e\n\n\u003ch3\u003eSimple Connection\u003c\/h3\u003e\n\n\u003cp\u003eThe telescope side is a standard 2\" barrel that slides directly into the AT80ED's focuser. The barrel includes 2\" filter threads, so you can thread in a light pollution or narrowband filter inline — no separate filter drawer needed. The camera side terminates in M42×0.75 T-threads, connecting to a T-ring for DSLR and mirrorless bodies, or directly to dedicated CMOS and CCD astronomy cameras, which come with 42mm T-threads built in.\u003c\/p\u003e\n\n\u003cp\u003eBack focus is 55mm from the reducer's shoulder to the imaging plane. For most DSLR setups with a standard T-ring, that spacing is close to correct out of the box. Dedicated astro cameras may need a spacer or two to dial it in precisely — and it's worth getting right, because back focus is where the difference between round stars and stretched stars lives.\u003c\/p\u003e\n\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e0.8× dedicated optical reduction.\u003c\/strong\u003e Drops the AT80ED from 560mm f\/7 to 448mm f\/5.6 — 56% more light per pixel and a wider field of view. That's the difference between a 4-minute sub and a 2.5-minute sub for the same signal.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eField flattening across APS-C and smaller sensors.\u003c\/strong\u003e Corrects native field curvature so stars are round from center to edge on APS-C, Micro Four Thirds, and dedicated astro camera sensors up to ~16mm diagonal.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e2\" filter thread built in.\u003c\/strong\u003e Thread a 2\" light pollution, UHC, or narrowband filter directly into the reducer barrel. No filter drawer, no extra adapters, no added back focus to recalculate.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eM42×0.75 T-thread camera connection.\u003c\/strong\u003e DSLR and mirrorless bodies connect via a T-ring (sold separately); dedicated CMOS\/CCD astronomy cameras attach directly — 42mm T-threads are standard on most.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e55mm back focus.\u003c\/strong\u003e Measured from the reducer shoulder to the imaging plane. Standard DSLR T-ring spacing typically hits this naturally. Dedicated cameras may need spacing adjustment.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e2\" barrel — slides into the AT80ED focuser.\u003c\/strong\u003e No adapters between reducer and focuser. Simple, secure, and repeatable positioning every session.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFully multi-coated optics.\u003c\/strong\u003e Maximizes light transmission and minimizes internal reflections that can reduce contrast in your images.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompact and lightweight.\u003c\/strong\u003e 5.24 oz — adds almost nothing to your imaging train weight or balance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eCommunity Says\u003c\/h3\u003e\n\n\u003cp\u003eCloudy Nights observers imaging with the AT80EDRF:\u003c\/p\u003e\n\n\u003cp\u003e\"I use the Astronomics dedicated 0.8x on my AT80ED. I use also a small sensor 533mc and it works perfectly… For the price I have nothing but praise.\"\u003c\/p\u003e\n\n\u003cp\u003e\"I added the AT80EDRF reducer-flattener for use in astro-imaging… I think it gives a good indication of round stars and flat field. This is with a 533MC Pro camera.\"\u003c\/p\u003e\n\n\u003cp\u003e\"I ordered the AT flattener with confidence.\"\u003c\/p\u003e\n\n\u003ch3\u003eObserving Tip\u003c\/h3\u003e\n\n\u003cp\u003eBack focus matters more than most beginners expect. If your stars look fine in the center but stretch toward the edges, you probably don't have an optical problem — you have a spacing problem. Measure the distance from the reducer's shoulder to your sensor and aim for 55mm. A set of M42 spacer rings (available in 1mm, 2mm, and 5mm) lets you dial it in without guesswork. Get the spacing right once, mark your configuration, and you won't have to think about it again.\u003c\/p\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\n\u003cp\u003e\u003cstrong\u003eDoes this work with the AT80EDT (triplet)?\u003c\/strong\u003e\u003cbr\u003e\nNo. The AT80EDRF is designed specifically for the AT80ED doublet (2018 and newer). The AT80EDT is a different optical design with a different focal length and field curvature. The AT80EDT has its own dedicated reducer and field flattener options — check those product pages for the correct match.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWill this work with a full-frame camera?\u003c\/strong\u003e\u003cbr\u003e\nIt will physically connect, but the corrected image circle does not cover a full-frame sensor. You'll see noticeable vignetting in the outer third of the frame. For full-frame imaging, you'd need a reducer designed for a larger image circle. This reducer is optimized for APS-C and smaller sensors.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat cameras work best with this reducer?\u003c\/strong\u003e\u003cbr\u003e\nAPS-C DSLRs (Canon Rebel\/EOS, Nikon DX), Micro Four Thirds bodies, and dedicated CMOS astronomy cameras with sensors up to about 16mm diagonal. The ZWO ASI533MC, ASI294MC, and similar cameras are confirmed to work well by Cloudy Nights users.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDo I need a T-ring?\u003c\/strong\u003e\u003cbr\u003e\nIf you're using a DSLR or mirrorless camera, yes — you need a T-ring for your specific camera mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have M42 T-threads built in and connect directly without a T-ring.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCan I use a filter with this reducer?\u003c\/strong\u003e\u003cbr\u003e\nYes. The 2\" barrel has internal filter threads. You can thread in a 2\" light pollution filter, UHC, or narrowband filter before inserting the reducer into the focuser. One CN user noted that placing filters in a drawer (rather than front-threading) can help fine-tune back focus if you run into spacing issues.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eHow critical is back focus?\u003c\/strong\u003e\u003cbr\u003e\nVery. The reducer is optimized for 55mm from its shoulder to the sensor. If your spacing is off by more than a millimeter or two, you'll see elongated stars toward the edges. M42 spacer rings let you adjust in small increments. Get it right once and it stays right.\u003c\/p\u003e\n\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\n\u003cp\u003eIf you're imaging with an AT80ED and you don't have a reducer yet, this is the one that was designed for your scope. It's not trying to be a universal solution — it's a precision match for this specific optical system, and that specificity is exactly why it delivers flat fields and round stars where generic reducers fall short. At $90, it turns a good visual scope into a capable widefield imaging system. Pair it with an APS-C DSLR or a small-sensor astro camera, get the back focus dialed in, and start shooting.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003ctable style=\"width:100%; border-collapse: collapse;\"\u003e\n  \u003ctbody\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eModel\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT80EDRF\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eOptical Reduction\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e0.8×\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Compatibility\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAstro-Tech AT80ED (2018 model year and newer)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eOriginal Focal Length\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e560mm (AT80ED native)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eReduced Focal Length\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e448mm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eResulting Focal Ratio\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003ef\/5.6\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eSensor Coverage\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eAPS-C and smaller (not full frame)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eTelescope Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e2\" barrel with 2\" filter threads\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCamera Side Connection\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eM42×0.75 T-threads\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eBack Focus\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e55mm (reducer shoulder to sensor)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eCoatings\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eFully multi-coated\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #ffffff;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWeight\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e5.24 oz\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f0f4f8;\"\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc; font-weight: bold; width: 50%;\"\u003eWarranty\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1 year limited\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":41639404798025,"sku":"AT80EDRF","price":89.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/image_87df4bf9-fe20-41c1-853b-616a4a013b7a.png?v=1722420579"},{"product_id":"questar-achromatic-0-44x-focal-reducer","title":"Questar Achromatic 0.44x Focal Reducer","description":"\u003cp\u003e\u003cspan\u003eThis Questar 0.44x achromatic focal reducer gives you faster photographic speeds with both 3.5\" and 7\" Questars.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eThis 100mm focal length positive achromatic lens acts as a 0.44x focal reducer for imaging with both the 3.5\" and 7\" Questars. It threads into the Questar camera adapter, between the scope and your camera. \u003c\/p\u003e\n\u003cp\u003eWhen used with a 3.5\" Questar, the Questar 0.6x reducer turns the 1300mm f\/14.4 Questar into a 572mm f\/6.3 lens. \u003c\/p\u003e\n\u003cp\u003eWhen used with a 7\" Questar, the Questar 0.6x reducer turns the 2400mm f\/13.4 Questar into a 1056mm f\/5.9 lens. \u003c\/p\u003e\n\u003cp\u003eThe image above of the Questar 0.6x focal reducer shows where it fits into the Questar camera adapter. This #39490 0.44x focal reducer is similar in appearance. \u003c\/p\u003e\n\u003cp\u003eShipping is free on this Questar item if it is purchased with a Questar scope that is being drop-shipped to you from the Questar factory. If this item is being purchased by itself as a special order item, a $12.95 freight charge and a 14-day or longer delivery time will apply. The $12.95 freight and a $20 Questar drop-ship charge will apply if faster delivery is required and it must be drop-shipped to you from Questar.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c!----\u003e","brand":"question","offers":[{"title":"Default Title","offer_id":41643800199241,"sku":"39490","price":595.0,"currency_code":"USD","in_stock":false}]},{"product_id":"questar-achromatic-0-6x-focal-reducer","title":"Questar Achromatic 0.6x Focal Reducer","description":"\u003cp\u003e\u003cspan\u003eThis Questar 0.6x achromatic focal reducer gives you faster photographic speeds with both 3.5\" and 7\" Questars.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eThis 130mm focal length positive achromatic lens acts as a 0.6x focal reducer for imaging with both the 3.5\" and 7\" Questars. It threads into the Questar camera adapter, between the scope and your camera. \u003c\/p\u003e\n\u003cp\u003eWhen used with a 3.5\" Questar, the Questar 0.6x reducer turns the 1300mm f\/14.4 Questar into a 780mm f\/8.6 lens. \u003c\/p\u003e\n\u003cp\u003eWhen used with a 7\" Questar, the Questar 0.6x reducer turns the 2400mm f\/13.4 Questar into a 1440mm f\/8 lens. \u003c\/p\u003e\n\u003cp\u003eThe image above of the Questar 0.6x focal reducer shows where it fits into the Questar camera adapter. \u003c\/p\u003e\n\u003cp\u003eShipping is free on this Questar item if it is purchased with a Questar scope that is being drop-shipped to you from the Questar factory. If this item is being purchased by itself as a special order item, a $12.95 freight charge and a 14-day or longer delivery time will apply. The $12.95 freight and a $20 Questar drop-ship charge will apply if faster delivery is required and it must be drop-shipped to you from Questar.\u003c\/p\u003e\n\u003ch2\u003eTech Details: \u003c\/h2\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c!----\u003e","brand":"question","offers":[{"title":"Default Title","offer_id":41643846795337,"sku":"39505","price":595.0,"currency_code":"USD","in_stock":false}]},{"product_id":"zwo-0-75x-reducer-for-ff65apo-telescope","title":"ZWO 0.75x Reducer For FF65APO Telescope","description":"\u003cp\u003e\u003cspan\u003eIf you are needing a faster version of your ZWO FF65APO Quad, this reducer will take your f\/ratio from f\/6.4 to f\/4.8.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cmeta charset=\"UTF-8\"\u003eZWO has released a brand-new FF65APO 0.75× full frame reducer with a four-element optical design. It has a reduction factor of 0.75x, which gives the FF65APO f\/6.4 astrograph a shortened focal ratio of f\/4.8 and a shorter focal length of 312mm. This allows for less total integration time and a wider field of view, bringing more convenience and possibilities for your wide-field deep sky imaging. The back focus distance is the standard 55mm. It also comes with two thread adapters of M54 and M48, and a built-in M48x0.75 2” filter thread, which makes the connection work simple and convenient. Connecting to the APO is fairly simple. Unscrew the eyepiece holder on the end of the focuser, then simply thread the reducer in its place.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eTech Details: \u003c\/span\u003e\u003c\/h2\u003e\n\u003ctable class=\"table\" id=\"product-attribute-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWarranty\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2 years\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c!----\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":41643948310601,"sku":"ZWOF65RE","price":249.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/image_9262d7d3-2928-4fed-858b-8a923e6e8382.jpg?v=1722622715"},{"product_id":"takahashi-toa-35-7x-reducer-w-ca-ring-for-tsa-120-or-toa-150","title":"Takahashi TOA-35 .7x Reducer w\/CA Ring for TSA-120 or TOA-150","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eThe TOA-35 Reducer is a 0.7X reducer for use with the TSA-120, TOA-130 and TOA-150 telescopes.  The reducer consists of 4 elements in 3 groups and utilizes ED glass, and produces a 44 mm diameter image circle.  When used with the TOA-130 and -150, the appropriate adapter ring is required.  \u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThis model is specific for the TSA-120 or TOA-150\u003c\/span\u003e\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":41837455114313,"sku":"TKA32580NS","price":1320.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/IMG_4754.jpg?v=1730753283"},{"product_id":"takahashi-toa-35-0-7x-reducer-with-ca-ring-for-toa-130","title":"Takahashi TOA-35 0.7x Reducer with CA Ring for TOA-130","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eThe TOA-35 Reducer is a 0.7X reducer for use with the TSA-120, TOA-130 and TOA-150 telescopes.  The reducer consists of 4 elements in 3 groups and utilizes ED glass, and produces a 44 mm diameter image circle.  When used with the TOA-130 and -150, the appropriate adapter ring is required.  \u003c\/span\u003e\u003c\/p\u003e","brand":"Takahashi","offers":[{"title":"Default Title","offer_id":41843815972937,"sku":"TKA31580NS","price":1320.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/IMG_4754.jpg?v=1730753283"},{"product_id":"televue-reducer-flattener-for-tv-np101-np101is-and-tv-np127-np127is","title":"TeleVue 0.8x Reducer Flattener For TV-NP101\/NP101is and TV-NP127\/NP127is","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003eA reducer has the optical property of decreasing the effective focal length of a telescope. This results in a wider-field and faster imaging time on nebulae and galaxies. Model NPR-2073 \u003c\/span\u003e\u003ci\u003e0.8x Reducer for NP Scopes\u003c\/i\u003e\u003cspan\u003e is specifically designed to be used with the NP127is and NP101is. While it can also be used to enlarge the field of other Tele Vue Petzval type telescopes, it will not provide additional correction for those models. This reducer was designed to minimize vignetting with camera sensors up to 43mm diagonal (Full Frame) and is a replacement for the previous 0.8x reducer, the NPR-1073, which worked best up to APS-C sensors. When combined with a Tele Vue Petzval type telescope, it reduces the focal length of the telescope by 20% and makes it that much faster. This increases the telescope's field of view by 25%.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eFor use on other Tele Vue Petzval model telescopes with 2-inch focusers, use the RAD-1074\u003cspan\u003e \u003c\/span\u003e\u003ci\u003eImaging System Nosepiece for 2\" Focuser\u003c\/i\u003e\u003cspan\u003e \u003c\/span\u003einstead of the I.S. Imaging Adapter. Note that when used with 2\" focusers there will be increased vignetting for full frame sensors because of the inner diameter of the 2-inch barrel.\u003c\/p\u003e\n\u003cp\u003eThis reducer requires the Imaging System insert to attach to the drawtube and Imaging System rings to attach to your accessories and camera. See NPR-2073\u003cspan\u003e \u003c\/span\u003einstructions\u003cspan\u003e \u003c\/span\u003efor details on how to use this reducer. See\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/televue.com\/engine\/TV3b_page.asp?id=37\"\u003eImaging System Accessories\u003c\/a\u003e\u003cspan\u003e \u003c\/span\u003efor more Imaging System options.\u003c\/p\u003e","brand":"TeleVue","offers":[{"title":"Default Title","offer_id":41866642194505,"sku":"NPR2073","price":572.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/NPR_2073_w250.jpg?v=1732228311"}],"url":"https:\/\/astronomics.com\/collections\/flatteners-reducers-extenders.oembed?page=6","provider":"Astronomics","version":"1.0","type":"link"}