{"title":"Barlows","description":"","products":[{"product_id":"2-4x-dakin-barlow-for-1-25-eyepieces","title":"Vernonscope Ralph Dakin 2.4X Dakin Barlow for 1.25\" Eyepieces","description":"\u003cp\u003eThis Ralph Dakin doublet design is considered by many professional astronomers to be the Rolls-Royce of 1.25\" Barlows. It has a magnification of 2.4x for non-repeating eyepiece powers. \u003cbr\u003eThis Ralph Dakin doublet design is considered by many professional astronomers to be the Rolls-Royce of Barlows. It has a magnification of 2.4x for non-repeating eyepiece powers. A non-marring nylon thumbscrew holds eyepieces securely in place. The lenses are antireflection coated, but not multicoated. One reason not to multicoat is to eliminate or greatly reduce a phenomenon known as \"narrow angle light scatter.\" Multicoatings have more narrow angle scatter than single layer coatings. You can see this effect on bright objects like Venus, Mars, or Jupiter, where scattered light can greatly interfere with low contrast detail. You can also notice a difference in the background darkness immediately surrounding a bright object, which is especially important for planetary or close binary star observing. In addition, lunar detail such as the bands of Aristarchus are usually better defined. The barrel has internal antireflection threading to further improve contrast. Its 4.25\" length allows its use in many star diagonals. The Dakin Barlow performs best with scopes f\/6 and above.\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\"\u003e4.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2.4x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e4 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":"Vernonscope","offers":[{"title":"Default Title","offer_id":40221633871945,"sku":"770","price":210.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/2019-07-09_20_46_46_2.4x_barlow_1.25-jxwiwkj3kaxk.png?v=1723838253"},{"product_id":"5x-powermate-image-amplifier-for-1-25-eyepieces","title":"TeleVue 5X Powermate Image Amplifier for 1.25\" Eyepieces","description":"\u003cp\u003eIf you \u003cem\u003emust \u003c\/em\u003ewear glasses while observing, and you're looking for an ultra high power Barlow to get high magnifications from your favorite long focal length\/long eye relief eyepieces, look no further than this 5x Powermate. While not technically a Barlow, this unique new 4-lens image amplifier performs the same functions, but at a higher level of optical correction.\u003c\/p\u003e\n\u003cp\u003eBarlow lenses have a negative power that diverges field rays, lengthening the effective focal length of the telescope and increasing the magnification. If Barlows are made too short or with too much magnification, the diverging rays can cause severe vignetting and image degradation in eyepieces due to mismatched pupils.\u003c\/p\u003e\n\u003cp\u003eThe Powermate is a 4-element parfocal compact amplifying lens system that consists of a negative achromatic doublet (a Barlow) plus a positive \"pupil-correcting\" doublet. While it looks and functions like a Barlow, your eyepieces will operate with pupil locations where the eyepiece designer intended, avoiding vignetting and mismatch problems with wide field eyepieces. The Powermate optimally mates its power to your eyepieces.\u003c\/p\u003e\n\u003cp\u003eIt is fully multicoated, with blackened lens edges and internal antireflection threading for excellent contrast. Its barrel is threaded for standard 1.25\" filters. There's an undercut safety groove in the barrel that helps hold the Powermate in place should the focuser thumbscrew accidentally loosen. A non-marring brass clamp ring (with a captive thumbscrew that can't be lost in the field) holds your eyepieces securely in place. The Powermate has a 3.8\" length and a short chrome barrel that allows it to be used in star diagonals.\u003c\/p\u003e\n\u003cp\u003eThis TeleVue is parfocal with TeleVue Plössls below 32mm in focal length, so you won't have to do any major refocusing as you change from an eyepiece alone to an eyepiece\/Powermate combination. It is optically corrected down to f\/4 for use with fast f\/ratio reflectors, but will provide excellent performance with any telescope type or focal ratio. It is parfocal with the 1.25\" diagonal of the TeleVue Ranger for quick power changes during terrestrial observing.\u003c\/p\u003e\n\u003cp\u003eThe chrome barrel containing the Powermate's optics can be removed from the black eyepiece holder section and used for lunar and terrestrial photography with close coupling cameras or CCD imagers. It is particularly useful for increasing the photographic magnification with short focal length refractors. An optional T-ring adapter, 81PMT, is needed to connect the chrome optical portion of the Powermate to a camera or CCD imager.\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\"\u003e3.8\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e5x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e6 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":40221655859273,"sku":"7650T","price":260.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/PMT_5126_PowerMate_5x_V2copy.jpg?v=1723670001"},{"product_id":"2-5x-powermate-image-amplifier-for-1-25-eyepieces","title":"TeleVue 2.5X Powermate Image Amplifier for 1.25\" Eyepiece","description":"\u003cp\u003eWhile not technically a Barlow, this unique new 4-lens 2.5x image amplifier performs the same functions, but at a higher level of optical correction. Barlow lenses have a negative power that diverges field rays, lengthening the effective focal length of the telescope and increasing the magnification. If Barlows are made too short or with too much magnification, the diverging rays can cause severe vignetting and image degradation in eyepieces due to mismatched pupils.\u003c\/p\u003e\n\u003cp\u003eThe Powermate is a 4-element parfocal amplifying lens system that consists of a negative achromatic doublet (a Barlow) plus a positive \"pupil-correcting\" doublet. While it looks and functions like a Barlow, your eyepieces will operate with pupil locations where the eyepiece designer intended, avoiding vignetting and mismatch problems with wide field eyepieces. The Powermate optimally mates its power to your eyepieces.\u003c\/p\u003e\n\u003cp\u003eIt is fully multicoated, with blackened lens edges and internal antireflection threading for excellent contrast. Due to its mechanical design, its barrel is \u003cem\u003enot \u003c\/em\u003ethreaded for eyepiece filters. There's an undercut safety groove in the barrel that helps hold the Powermate in place should the focuser thumbscrew accidentally loosen. A non-marring brass clamp ring (with a captive thumbscrew that can't be lost in the field) holds your eyepieces securely in place. The Powermate is 3.8\" long, with a short chrome barrel that allows it to be used in star diagonals.\u003c\/p\u003e\n\u003cp\u003eThis TeleVue is parfocal with TeleVue Plössls below 32mm in focal length, so you won't have to do any major refocusing as you change from an eyepiece alone to an eyepiece\/Powermate combination. It is optically corrected down to f\/4 for use with fast f\/ratio reflectors, but will provide excellent performance with any telescope type or focal ratio. It is parfocal with the 1.25\" diagonal of the TeleVue Ranger for quick power changes during terrestrial observing.\u003c\/p\u003e\n\u003cp\u003eThe chrome barrel containing the Powermate's optics can be removed from the black eyepiece holder section and used for lunar and terrestrial photography with close coupling cameras or CCD imagers. It is particularly useful for increasing the photographic magnification with short focal length refractors. An optional T-ring adapter, #81PMT, is needed to connect the chrome optical portion of the Powermate with a camera or CCD imager.\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\"\u003e3.8\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e6 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":40221655924809,"sku":"7625T","price":260.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/PMT_2513_Powermate_2.5x_V2copy.jpg?v=1723666940"},{"product_id":"2x-barlow-for-1-25-eyepieces","title":"TeleVue 2X Barlow for 1.25\" Eyepieces","description":"\u003cp\u003eThis 2-element Barlow has superb sharpness to match that of TeleVue eyepieces. Despite being \"merely\" an achromatic system, good design gives it better color correction at the edges of the field than some 3-element \"apochromatic\" Barlows.\u003c\/p\u003e\n\u003cp\u003eIt is fully multicoated, with blackened lens edges and internal antireflection threading for excellent contrast. Its barrel is threaded for standard 1.25\" filters. There's an undercut safety groove in the barrel that helps hold the Barlow in place should the focuser thumbscrew accidentally loosen. A captive thumbscrew (that can't be lost in the field) holds your eyepieces in place. It has a 3.75\" length that allows it to be used in star diagonals.\u003c\/p\u003e\n\u003cp\u003eThis TeleVue is parfocal with TeleVue Plössls below 32mm in focal length, so you won't have to do any major refocusing as you change from an eyepiece alone to an eyepiece\/Barlow combination. It is optically corrected down to f\/4 for use with fast f\/ratio reflectors, but will provide excellent performance with any scope type.\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\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":40221656121417,"sku":"7620","price":153.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/BLW_2125_Barlow_2x_V2copy.jpg?v=1723667791"},{"product_id":"3x-barlow-for-1-25-eyepieces","title":"TeleVue 3X Barlow for 1.25\" Eyepieces","description":"\u003cp\u003eIf you need a high quality, medium high power Barlow for 1.25\" eyepieces, look no further than this TeleVue. It's a 2-lens achromatic design with superb sharpness to match that of TeleVue eyepieces. It is fully multicoated, with blackened lens edges and internal antireflection threading for excellent contrast. Its barrel is threaded for standard 1.25\" filters. There's an undercut safety groove in the barrel that helps hold the Barlow in place should the focuser thumbscrew accidentally loosen. A non-marring brass clamp ring holds eyepieces securely in place. A captive thumbscrew (that can't be lost in the field) controls the clamp ring tension.\u003c\/p\u003e\n\u003cp\u003eIts 5\" length is marginal for use in star diagonals, however, as its length (combined with a physically long eyepiece) can put your eye nearly 7\" above the diagonal when observing. This poses no optical problems, but some inexpensive diagonals have rather loose tolerances. The weight of the very long Barlow\/eyepiece combination may cause the diagonal housing to loosen where it fits into the visual back and pivot unexpectedly.\u003c\/p\u003e\n\u003cp\u003eThis TeleVue 3x is parfocal with TeleVue Plössls below 32mm in focal length, so you won't have to do any major refocusing as you change from an eyepiece alone to an eyepiece\/Barlow combination. It is optically corrected down to f\/4 for use with fast f\/ratio reflectors, but will provide excellent performance with any scope type. Due to the length of the Barlow, the accessory container recommended below is substantially larger in diameter than is needed for a snug side-to-side fit, even though the container length is correct to hold the Barlow without rattling.\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\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e7 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":40221656219721,"sku":"7630","price":153.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/BLW_3125_Barlow_3x_V2copy.jpg?v=1723669243"},{"product_id":"2x-barlow-for-1-25-eyepieces-includes-t-adapter","title":"Celestron 2X Barlow for 1.25\" Eyepieces (Includes T-Adapter)","description":"\u003cp\u003eThis 1.25\" 2x achromatic Barlow lens can be used visually, but the eyepiece holder portion also has integral T-threads so it can be used as a T-adapter for lunar and terrestrial photography. The physically short (2.9\") Barlow fits into the rack and pinion focuser drawtube of most equatorial refractors and reflectors. It can also be used in the 1.25\" visual back or eyepiece holder of most Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. However, use with these scopes is not particularly recommended as the weight of the camera will be held in place by only the thumbscrew on the eyepiece holder, and your camera might wind up on the ground if the temperature drops and the metal of the thumbscrew contracts and loses its grip on the Barlow.\u003c\/p\u003e\n\u003cp\u003ePhotographically, the Barlow doubles the effective focal length and focal ratio of the telescope and acts as a transfer lens to project a two times enlarged image onto the film plane of your camera for close-up lunar and terrestrial photography. It can also be used with many reflectors that do not have a moveable primary mirror or with refractors that do not have enough focuser in-travel to reach focus with a conventional camera adapter. Some vignetting may be visible with very short focal length telescopes. Needs optional T-ring for photographic 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\"\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eLength\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2.9\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e4 oz\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":"Celestron","offers":[{"title":"Default Title","offer_id":40221656416329,"sku":"705T","price":69.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/93640-T_Adapter_Barlow_01_570x380_2x_630e0871-4a58-440a-94e6-52ab33dd83fb.webp?v=1721419014"},{"product_id":"4x-powermate-image-amplifier-for-2-eyepieces-with-1-25-eyepiece-adapter","title":"TeleVue 4X Powermate Image Amplifier for 2\" Eyepieces, with 1.25\" Eyepiece Adapter","description":"\u003cp\u003eIf you need a very high quality, very high power 4x Barlow for 2\" eyepieces, look no further than this TeleVue Powermate. While not technically a Barlow, this unique new 4-lens image amplifier performs the same functions, but at a higher level of optical correction.\u003c\/p\u003e\n\u003cp\u003eBarlow lenses have a negative power that diverges field rays, lengthening the effective focal length of the telescope and increasing the magnification. If Barlows are made too short or with too much magnification, the diverging rays can cause severe vignetting and image degradation in eyepieces due to mismatched pupils.\u003c\/p\u003e\n\u003cp\u003eThe Powermate is a 4-element parfocal compact amplifying lens system that consists of a negative achromatic doublet (a Barlow) plus a positive \"pupil-correcting\" doublet. While it looks and functions like a Barlow, your eyepieces will operate with pupil locations where the eyepiece designer intended, avoiding vignetting and mismatch problems with wide field eyepieces. The Powermate optimally mates its power to your eyepieces. No additional \"interface lens\" is needed, since the Powermate already has it built-in.\u003c\/p\u003e\n\u003cp\u003eThe Powermate is fully multicoated, with blackened lens edges and internal antireflection threading for excellent contrast. There's an undercut safety groove in the barrel that helps hold the Powermate in place should the focuser thumbscrew accidentally loosen. The Powermate is threaded to hold 48mm filters. It is 5.25\" in length, but the chrome barrel is only 1.5\" long, allowing use of the Powermate in star diagonals. Both the 2\" eyepiece holder and the supplied low-profile 2\" to 1.25\" eyepiece adapter use brass clamp rings for secure, non-marring operation. A captive thumbscrew in the Powermate (that can't be lost in the field) operates its clamp ring.\u003c\/p\u003e\n\u003cp\u003eIt is optically corrected down to f\/4 for use with fast f\/ratio reflectors, but does not correct the coma inherent in such scopes. If used with the 2\" Paracorr in fast focal ratio reflectors, the Powermate should go into the focuser first, with the Paracorr being inserted into the Powermate body.\u003c\/p\u003e\n\u003cp\u003eAn optional T-ring adapter, #9140T, is available to allow the 2x Powermate to be used for lunar and terrestrial photography with short focal length refractors.\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\"\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\"\u003e4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e4x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e22 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":"TeleVue","offers":[{"title":"Default Title","offer_id":40221657268297,"sku":"9140C","price":396.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/PMT_4201_PowerMate_4x_V2copy.jpg?v=1723669756"},{"product_id":"2x-big-barlow-for-2-eyepieces-with-1-25-eyepiece-adapter","title":"TeleVue 2X Big Barlow for 2\" Eyepieces, with 1.25\" Eyepiece Adapter","description":"\u003cp\u003eThis 2\" 2x Clamp Ring Big Barlow can be used with any telescope using a 2\" focuser. As it is only 4.5\" long, it can also be used \u003cem\u003ein \u003c\/em\u003emost 2\" star diagonals for 2x magnification.\u003c\/p\u003e\n\u003cp\u003eIt can also be placed into a 2\" focuser \u003cem\u003ein front of \u003c\/em\u003ea 2\" star diagonal to give higher magnification than the nominal 2x. Some refractors might not have enough focuser travel to allow this directly, however. For example, all 2\" focuser TeleVue refractors require adding a 3.5\" extension tube #1343C between the scope and Barlow to allow the Barlow and eyepiece to reach focus. In this configuration, the magnification is about 3.3x instead of the expected 2x.\u003c\/p\u003e\n\u003cp\u003eThis Big Barlow uses non-marring brass clamp rings to hold 2\" eyepieces and the supplied low profile 1.25\" eyepiece adapter in place. The captive thumbscrew on the Barlow that tightens its clamp ring can't be lost in the field. The Barlow is parfocal with TeleVue eyepieces. The Barlow is antireflection threaded, with blackened lens edges for high contrast. It is fully multicoated and threaded for 48mm filters. The Barlow is corrected for use with telescopes having focal ratios down to f\/4.\u003c\/p\u003e\n\u003cp\u003eUsing the Big Barlow with 27mm and 35mm Panoptic eyepieces requires an optional #PAN00 interface lens to maintain eye relief, avoid vignetting, and improve the field edge performance. The #PAN00 interface is helpful, but not essential, with the 22mm Panoptic, but is not needed with the 15mm or 19mm Panoptics.\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\"\u003e4.5\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e15 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":40221657301065,"sku":"9120C","price":260.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/BWC_2211_BigBarlow_2x_v3.jpg?v=1723489432"},{"product_id":"2x-powermate-image-amplifier-for-2-eyepieces-with-1-25-eyepiece-adapter","title":"TeleVue 2X Powermate Image Amplifier for 2\" Eyepieces, with 1.25\" Eyepiece Adapter","description":"\u003cp\u003eIf you need a very high quality 2x Barlow for 2\" eyepieces, look no further than this TeleVue Powermate. While not technically a Barlow, this unique new 4-lens image amplifier performs the same functions, but at a higher level of optical correction. Barlow lenses have a negative power that diverges field rays, lengthening the effective focal length of the telescope and increasing the magnification. If Barlows are made too short or with too much magnification, the diverging rays can cause severe vignetting and image degradation in eyepieces due to mismatched pupils.\u003c\/p\u003e\n\u003cp\u003eThe Powermate is a 4-element parfocal compact amplifying lens system that consists of a negative achromatic doublet (a Barlow) plus a positive \"pupil-correcting\" doublet. While it looks and functions like a Barlow, your eyepieces will operate with pupil locations where the eyepiece designer intended, avoiding vignetting and mismatch problems with wide field eyepieces. The Powermate optimally mates its power to your eyepieces. No additional \"interface lens\" is needed, since the Powermate already has it built-in.\u003c\/p\u003e\n\u003cp\u003eThis model is nearly parfocal (unlike the 2\" Big Barlow\/Interface Lens combination), so it can be effectively used in TeleVue 2\" diagonals. Its performance is excellent with every 1.25\" or 2\" TeleVue eyepiece made, even the 31mm Nagler Type 5, so you won't have to do any major refocusing as you change from an eyepiece alone to an eyepiece\/Powermate combination.\u003c\/p\u003e\n\u003cp\u003eIt is fully multicoated, with blackened lens edges and internal antireflection threading for excellent contrast. Both the 2\" eyepiece holder and the supplied low-profile 2\" to 1.25\" eyepiece adapter use brass clamp rings for secure, non-marring operation. A captive thumbscrew on the Powermate (that can't be lost in the field) operates its clamp ring. There's an undercut safety groove in the barrel of the 1.25\" adapter that helps hold it and the eyepiece in place should the Powermate thumbscrew accidentally loosen. The Powermate is optically corrected down to f\/4 for use with fast f\/ratio reflectors, but will provide excellent performance with any telescope type or focal ratio.\u003c\/p\u003e\n\u003cp\u003eAn optional T-ring adapter, #9122T, is available to allow the 2x Powermate to be used for lunar and terrestrial photography with short focal length refractors.\u003c\/p\u003e","brand":"TeleVue","offers":[{"title":"Default Title","offer_id":40221657464905,"sku":"9122","price":388.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/PMT_2200_PowerMate_2x_V2copy.jpg?v=1723667974"},{"product_id":"2x-omni-barlow-for-1-25-eyepieces","title":"Celestron 2X Omni Barlow for 1.25\" Eyepieces","description":"\u003cp\u003eThis is a good quality 1.25\" 2x two-element fully multicoated Barlow. Its relatively short 3\" length allows use in star diagonals. A thumbscrew holds eyepieces in place. The titanium-colored body has blackened internal antireflection threading for improved contrast. Comes with plastic covers for both ends of the Barlow to keep the optics dust free.\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\"\u003e3\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e4 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":"Celestron","offers":[{"title":"Default Title","offer_id":40221657497673,"sku":"706","price":41.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/93326_Omni_2x_Barlow_Lens_01_570x380_2x_2598c95b-b7dd-433b-ab61-809a2ddf1728.webp?v=1721419122"},{"product_id":"explore-scientific-2x-barlow-for-1-25-eyepieces","title":"Explore Scientific 2X Barlow for 1.25\" eyepieces","description":"\u003cp\u003eThis four-element 1.25\" 2x Explore Scientific focal extender (Barlow lens) has an exceptionally flat field and essentially no color fringing with all telescope types and focal ratios.\u003c\/p\u003e\n\u003cp\u003eThe 1.25\" 2x Explore Scientific premium Barlow (described by Explore Scientific as a focal extender, rather than a Barlow) uses an advanced four-element optical design to deliver a flatter field of view with sharper field edges than even the best three-element apochromatic Barlows.\u003c\/p\u003e\n\u003cp\u003eThis Explore Scientific focal extender doubles the power of any 1.25\"eyepieces used with it, providing high powers while maintaining thecomfortable eye relief of longer focal length eyepieces. This makes aBarlow\/long focal length eyepiece combination ideal for those who \u003cem\u003emust \u003c\/em\u003ewear eyeglasses while observing due to astigmatism.\u003c\/p\u003e\n\u003cp\u003eAll air-to-glass surfaces are fully coated with multiple layers of individually tuned ion-deposited anti-reflection materials for maximum light transmission and contrast. The lens edges and all internal metal surfaces are blackened to maximize the image contrast. Your eyepieces are held in place by a non-marring clamp ring that won't scratch your eyepieces as a conventional metal thumbscrew can.\u003c\/p\u003e\n\u003cp\u003eWhile not specifically claimed to be apochromatic in performance, color fringing in this Explore Scientific focal extender is essentially eliminated with all telescope types and focal ratios.\u003c\/p\u003e\n\u003cp\u003eThis Explore Scientific focal extender is protected by a one year warranty that can be extended to a transferable limited product lifetime warranty at no cost by simply sending in the warranty card. With the extended product lifetime warranty, this Explore Scientific focal extender is protected for as long as it continues to be manufactured, plus an additional five years.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003cdiv class=\"tab-pane tabactive\" id=\"tab-1\"\u003e\n\u003cdiv class=\"tabcontent\"\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eItem Number\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003eFE02–125\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eBarrel Size\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e1.25-inch\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eLength\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e96mm\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eWidth\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e45mm\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eWeight\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e260 grams; 9.1 oz\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":40221672341577,"sku":"ESB1X2","price":119.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/2x_683x683_77ec04da-dd44-4905-b2f8-cbb8f5a37a72.webp?v=1722013586"},{"product_id":"explore-scientific-3x-barlow-for-1-25-eyepieces","title":"Explore Scientific 3X Barlow for 1.25\" eyepieces","description":"\u003cp\u003eThis new four-element 1.25\" 3x Explore Scientific focal extender (Barlow lens) triples the power of any eyepiece used with it, with flat-field and essentially apochromatic performance.  The 1.25\" 3x Explore Scientific premium focal extender (Barlow lens) uses an advanced four-element optical design to deliver a flatter field-of-view with sharper field edges than even the best three-element apochromatic Barlows.\u003c\/p\u003e\n\u003cp\u003eThis Explore Scientific focal extender triples the power of any 1.25\" eyepieces used with it, providing high powers while maintaining the comfortable eye relief of longer focal length eyepieces. This makes a Barlow\/long focal length eyepiece combination such as this ideal for those who \u003cem\u003emust \u003c\/em\u003ewear eyeglasses while observing due to astigmatism.\u003c\/p\u003e\n\u003cp\u003eAll air-to-glass surfaces are fully coated with multiple layers of individually tuned ion-deposited anti-reflection materials for maximum light transmission and contrast. The lens edges and all internal metal surfaces are blackened to maximize the image contrast. Your eyepieces are held in place by a non-marring clamp ring that won't scratch your eyepieces as a conventional metal thumbscrew can.\u003c\/p\u003e\n\u003cp\u003eWhile not specifically claimed to be apochromatic in performance, color fringing in this Explore Scientific 3x 1.25\" focal extender is essentially eliminated with all telescope types and focal ratios.\u003c\/p\u003e\n\u003cp\u003eThis Explore Scientific focal extender is protected by a one year warranty that can be extended to a transferable limited product lifetime warranty at no cost by simply sending in the warranty card. With the extended product lifetime warranty, this Explore Scientific focal extender is protected for as long as it continues to be manufactured, plus an additional five years.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eItem Number\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003eFE03–125\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eBarrel Size\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e1.25-inch\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eLength\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e93mm\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eWidth\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e45mm\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eWeight\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e249 grams; 8.7 oz\u003c\/span\u003e\n\u003c\/div\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":40221672407113,"sku":"ESB1X3","price":139.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/19242.jpg?v=1662967966"},{"product_id":"explore-scientific-5x-barlow-for-1-25-eyepieces","title":"Explore Scientific 5X Barlow for 1.25\" eyepieces","description":"\u003cp\u003eFor high power with a short focal length refractor or reflector, this Explore Scientific four-element 5x image amplifier (Barlow lens) is hard to beat. It quintuples the power of any eyepiece used with it, with a flat field and essentially no color fringing .\u003c\/p\u003e\n\u003cp\u003eThis very high power four-element 1.25\" 5x Explore Scientific premium focal extender (Barlow lens) uses an advanced four-element optical design to deliver a flatter field-of-view with sharper field edges than even the best three-element apochromatic Barlows.\u003c\/p\u003e\n\u003cp\u003eThis Explore Scientific focal extender multiplies the power of any 1.25\" eyepiece used with it by five times, providing very high powers while maintaining the comfortable eye relief of longer focal length eyepieces. This makes a Barlow\/long focal length eyepiece combination ideal for those who \u003cem\u003emust \u003c\/em\u003ewear eyeglasses while observing due to astigmatism.\u003c\/p\u003e\n\u003cp\u003eAll air-to-glass surfaces are fully coated with multiple layers of individually tuned ion-deposited anti-reflection materials for maximum light transmission and contrast. The lens edges and all internal metal surfaces are blackened to maximize image contrast. Your eyepieces are held in place by a non-marring clamp ring that won't scratch your eyepieces as a conventional metal thumbscrew can.\u003c\/p\u003e\n\u003cp\u003eIts very high power 5x optical system is a perfect match for short focal length refractors or reflectors - particularly for viewing or imaging planets in minute detail. While it is not specifically claimed to be apochromatic in performance, color fringing in this Explore Scientific focal extender is essentially eliminated, regardless of the telescope type and\/or focal ratio.\u003c\/p\u003e\n\u003cp\u003eThis Explore Scientific focal extender is protected by a one year warranty that can be extended to a transferable limited product lifetime warranty at no cost by simply sending in the warranty card. With the extended product lifetime warranty, this Explore Scientific focal extender is protected for as long as it continues to be manufactured, plus an additional five years.\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eItem Number\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003eFE05–125\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eBarrel Size\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e1.25-inch\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eLength\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e96mm\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eWidth\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e45mm\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eWeight\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e260 grams; 9.2 oz\u003c\/span\u003e\n\u003c\/div\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":40221672439881,"sku":"ESB1X5","price":129.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/19243.jpg?v=1662967968"},{"product_id":"explore-scientific-2x-barlow-for-2-eyepieces-with-1-25-adapter","title":"Explore Scientific 2X Barlow for 2\" eyepieces, with 1.25\" adapter","description":"\u003cp\u003eThis new four-element 2\" 2x Explore Scientific focal extender (Barlow lens) has a 1.25\" eyepiece adapter so you can use both 2\" and 1.25\" eyepieces in your 2\" focuser.\u003c\/p\u003e\n\u003cp\u003eThe 2\" 2x Explore Scientific premium Barlow (described by Explore Scientific as a focal extender, rather than a Barlow) uses an advanced four-element optical design that delivers a flatter field-of-view with sharper field edges than even the best three-element apochromatic Barlows. A 1.25\" adapter lets you use this Explore Scientific 2\" focal extender with your 1.25\" eyepieces, as well.\u003c\/p\u003e\n\u003cp\u003eThis Explore Scientific focal extender doubles the power of any 2\" or 1.25\"eyepieces used with it, providing high powers while maintaining thecomfortable eye relief of longer focal length eyepieces. You get all ofthe wide field of view of your 2\" eyepieces without degrading thesharpness at the edge of the field as a conventional Barlow can.\u003c\/p\u003e\n\u003cp\u003eAll air-to-glass surfaces are fully coated with multiple layers of individually tuned ion-deposited anti-reflection materials for maximum light transmission and contrast. The lens edges and all internal metal surfaces are  blackened to maximize the image contrast. Eyepieces are held in place in both the 2\" focal extender and the 1.25\" adapter by non-marring clamp rings that won't scratch your eyepieces as a conventional metal thumbscrew can. The 2\" barrel is threaded to hold 2\" filters.\u003c\/p\u003e\n\u003cp\u003eWhile it is not specifically claimed to be apochromatic in performance, the color fringing in this 2\" Explore Scientific focal extender is essentially eliminated for all practical purposes with all telescope types and focal ratios.\u003c\/p\u003e\n\u003cp\u003eThis Explore Scientific focal extender is protected by a one year warranty that can be extended to a transferable limited product lifetime warranty at no cost by simply sending in the warranty card. With the extended product lifetime warranty, this Explore Scientific focal extender is protected for as long as it continues to be manufactured, plus an additional five years.\u003cbr\u003e\u003c\/p\u003e\n\u003ch2\u003eTech Details:\u003c\/h2\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eItem Number\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003eFE02–020\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eBarrel Size\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e2.0-inch\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eLength\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e118mm\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eWidth\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e66mm\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"spanrow\"\u003e\n\u003cspan class=\"speccell speccell-left\"\u003eWeight\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan class=\"speccell\"\u003e20 oz; 0.57 kg\u003c\/span\u003e\n\u003c\/div\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":40221672505417,"sku":"ESB2X2","price":179.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/2xx_674x674_e40fa0fa-a37d-4d36-bfc2-66b7d97f93f0.webp?v=1722013679"},{"product_id":"celestron-x-cel-lx-2x-3-element-barlow-for-1-25-eyepieces","title":"Celestron X-Cel LX 2X 3-Element Barlow for 1.25\" Eyepieces 93529","description":"\u003cp\u003eThis 2x Celestron X-Cel LX three-lens air-spaced fully multicoated 1.25\" Barlow performs a lot more expensively than it costs.\u003c\/p\u003e\n\u003cp\u003eThis Celestron X-Cel LX 1.25\" Barlow is an air-spaced three-lens fully multicoated 2x Barlow that provides premium optical performance at a very non-premium price. It is optically corrected for use with any eyepiece type and telescope combination.\u003c\/p\u003e\n\u003cp\u003eIn addition to full multicoatings, the Celestron X-Cel LX Barlow has blackened lens edges and internal antireflection threading to virtually eliminate internal reflections. This assures high contrast images when observing bright targets, such as the Moon and planets.\u003c\/p\u003e\n\u003cp\u003eThe Celestron Barlow is threaded to accept standard 1.25\" color and light pollution filters. Its compact 3\" length allows you to use it comfortably in star diagonals. A non-marring brass compression ring holds your eyepieces securely in place. There's a rubber grip ring for a firm hold while handling the Barlow while wearing gloves in cold weather. A groove machined into the 1.25\" barrel acts as a safety stop should your focuser thumbscrew accidentally loosen.\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\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\"\u003e3\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e4 oz.\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":"Celestron","offers":[{"title":"Default Title","offer_id":40221673783369,"sku":"CB2X","price":124.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/93529-X-Cel_2x_Barlow_01_570x380_2x_cd09d8c7-e42b-4bbc-9a95-f2b470a54b95.webp?v=1721936788"},{"product_id":"x-cel-lx-3x-3-element-barlow-for-1-25-eyepieces","title":"Celestron X-Cel LX 3X 3-Element Barlow For 1.25\" Eyepieces  93428","description":"\u003cp\u003eThis three-power Celestron X-Cel LX 1.25\" Barlow is an air-spaced three-lens fully multicoated Barlow that provides premium optical performance at a very non-premium price. It is optically corrected for use with any eyepiece type and telescope combination.\u003c\/p\u003e\n\u003cp\u003eIn addition to full multicoatings, the Celestron X-Cel LX Barlow has blackened lens edges and internal antireflection threading to virtually eliminate internal reflections. This assures high contrast images when observing bright targets, such as the Moon and planets.\u003c\/p\u003e\n\u003cp\u003eThe Celestron Barlow is threaded to accept standard 1.25\" color and light pollution filters. Its compact 3.5\" length allows you to use it comfortably in star diagonals. A non-marring brass compression ring holds your eyepieces securely in place. There's a rubber grip ring for a firm hold while handling the Celestron Barlow while wearing gloves in cold weather. Comes with dust covers for both ends of the Barlow.\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\"\u003e3.5\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e3x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e4.5 oz.\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":"Celestron","offers":[{"title":"Default Title","offer_id":40481972027465,"sku":"CLXB3X","price":124.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/93428-Ex-Cel-3x-Barlow_01_570x380_2x_017170ee-2626-4698-8864-e07a3b90f03d.webp?v=1721936898"},{"product_id":"celestron-luminos-2-5x-4-element-barlow-for-2-and-1-25-eyepieces","title":"Celestron Luminos 2.5X 4-Element Barlow For 2\" And 1.25\" Eyepieces  93436","description":"\u003cp\u003eThis 2.5x magnification Celestron Luminos 2\" Barlow uses a four-lens fully multicoated optical system to provide a flat field and apochromatic-quality spurious color free optical performance. Affordably-priced, it is optically corrected for use with any eyepiece type and telescope combination and comes with an adapter to allow you to use either 2\" or 1.25\" eyepieces.\u003cbr\u003e\u003cbr\u003eIn addition to full multicoatings, the Celestron Luminos Barlow has blackened lens edges and internal antireflection threading to virtually eliminate internal reflections. This assures high contrast images when observing bright targets, such as the Moon and planets. A 28mm clear aperture minimizes vignetting, even when used with wide angle 2\" eyepieces.\u003cbr\u003e\u003cbr\u003eThe 2\" barrel of the Celestron Luminos Barlow is threaded to accept standard 2\" color and light pollution filters. Its compact 3.66\" length (with the 1.25\" adapter) allows you to use it comfortably in star diagonals. It is only 3.15\" long when the 1.25\" adapter is removed for use with 2\" eyepieces. \u003cbr\u003e\u003cbr\u003eNon-marring brass compression rings with large thumbscrews hold your eyepieces securely in place in both the 2\" barrel and the 1.25\" adapter without marring the eyepiece barrels as an ordinary Barlow thumbscrew can. There's a broad rubber grip ring for a firm hold while handling the Celestron Luminos Barlow while wearing gloves in cold weather. The Luminos Barlow comes in a soft vinyl drawstring pouch for storage.\u003cbr\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e \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\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\"\u003e3.66\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e2.5x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e11 oz.\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":"Celestron","offers":[{"title":"Default Title","offer_id":40481973993545,"sku":"CLUM25X","price":159.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/93436-Luminos-Barlow_01_570x380_2x_cbf8b611-ccce-4865-a609-30ed3a3e1516.webp?v=1721768236"},{"product_id":"explore-scientific-2-3x-focal-extender-barlow","title":"Explore Scientific 2\" 3x Focal Extender (Barlow)","description":"\u003cp\u003eThe 2\" 3x Explore Scientific premium Barlow (described by Explore Scientific as a focal extender, rather than a Barlow) uses an advanced four-element optical design that delivers a flatter field-of-view with sharper field edges than even the best three-element apochromatic Barlows. A 1.25\" adapter lets you use this Explore Scientific 2\" focal extender with your 1.25\" eyepieces, as well.\u003c\/p\u003e\n\u003cp\u003eThis Explore Scientific focal extender triples the power of any 2\" or 1.25\" eyepieces used with it, providing high powers while maintaining the comfortable eye relief of longer focal length eyepieces. You get all of the wide field of view of your 2\" eyepieces without degrading the sharpness at the edge of the field as a conventional Barlow can.\u003c\/p\u003e\n\u003cp\u003eAll air-to-glass surfaces are fully coated with multiple layers of individually tuned ion-deposited anti-reflection materials for maximum light transmission and contrast. The lens edges and all internal metal surfaces are blackened to maximize the image contrast. Eyepieces are held in place in both the 2\" focal extender and the 1.25\" adapter by non-marring clamp rings that won't scratch your eyepieces as a conventional metal thumbscrew can. The 2\" barrel is threaded to hold 2\" filters.\u003c\/p\u003e\n\u003cp\u003eWhile it is not specifically claimed to be apochromatic in performance, the color fringing in this 2\" Explore Scientific focal extender is essentially eliminated for all practical purposes with all telescope types and focal ratios.\u003c\/p\u003e\n\u003cp\u003eThis Explore Scientific focal extender is protected by a one year warranty that can be extended to a transferable limited product lifetime warranty at no cost by simply sending in the warranty card. With the extended product lifetime warranty, this Explore Scientific focal extender is protected for as long as it continues to be manufactured, plus an additional five years.\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\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\"\u003e5\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNumber of optical elements\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e3x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e22 ounces\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","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":40481983758409,"sku":"ESB2X3","price":179.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/products\/fe03-020_1_1493x_d5539661-428c-4ded-9bc3-556e7c215665.jpg?v=1675379569"},{"product_id":"astro-tech-2x-telecentric-extender-barlow-for-1-25-eyepieces","title":"Astro-Tech 2X Telecentric Extender Barlow for 1.25\" Eyepieces","description":"\u003cp\u003eYou have five eyepieces in a case and you need ten focal lengths. The obvious answer is a Barlow — double the power of every eyepiece you own in one accessory. But if you've used a cheap 2x Barlow, you know the tradeoffs: vignetting with wide-field eyepieces, blackouts with short eye relief designs, and a magnification factor that wanders depending on how far the eyepiece sits from the lens. The Astro-Tech 2X Telecentric Extender solves those problems with a four-element optical design that works the way a Barlow should have worked all along.\u003c\/p\u003e\n\u003cp\u003eA standard Barlow uses a single negative lens group. It diverges the light cone, which increases magnification but also pushes the exit pupil farther from the eyepiece. With long focal length eyepieces, that extended exit pupil can cause vignetting at the edges of the field. With short focal length eyepieces, the increased eye relief can make the view feel like you're looking down a tunnel. A telecentric design adds a second lens group — a positive \"pupil-correcting\" doublet — that redirects the field rays back to their original path. The result is a clean 2x magnification increase without altering the exit pupil position, the apparent field of view, or the eye relief characteristics of your eyepiece. The eyepiece behaves as if it were simply half the focal length.\u003c\/p\u003e\n\u003cp\u003eThe AT2XTB uses four fully multicoated elements. The coatings are applied to all air-to-glass surfaces, and the body is CNC-machined aluminum with an anodized black finish. The unit breaks down into two pieces: unthread the eyepiece holder section from the nosepiece and you expose a 42mm T-thread, which lets you attach the optical section directly to a camera body or T-ring for imaging at 2x your telescope's native focal length. The nosepiece is also threaded for standard 1.25\" filters, so you can stack a light pollution filter or a color planetary filter below the Barlow without needing a separate filter adapter.\u003c\/p\u003e\n\u003cp\u003eOne note on what \"telecentric\" means in practice: the magnification stays at a constant 2x regardless of the eyepiece spacing. With a standard Barlow, pulling the eyepiece farther from the lens increases the magnification beyond the rated 2x — useful as a trick, but unpredictable if you're trying to calculate actual magnification. The AT2XTB gives you a true, repeatable 2x every time. That matters if you're pairing it with specific eyepieces to hit target magnifications, or if you're using it with a binoviewer where the longer light path would shift a standard Barlow's magnification unpredictably.\u003c\/p\u003e\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eAstro-Tech 2X Telecentric Extender Barlow\u003c\/li\u003e\n\u003cli\u003eDust caps — eye end and barrel end\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCommunity Says\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003e\"The AT is the only one that completely cleans the view of ghosting in my BV, and that is quite the achievement.\"\u003c\/strong\u003e\u003cbr\u003e— \u003ca href=\"https:\/\/www.cloudynights.com\/forums\/topic\/873637-new-astro-tech-2x-telecentric-extender\/?do=findComment\u0026amp;comment=13286837\"\u003eCloudy Nights AT 2X Telecentric discussion\u003c\/a\u003e. This owner tested the AT telecentric against Baader and Siebert optic products for binoviewing in both a refractor and a Dobsonian. Of all the OCAs and barlows tested, the AT was the only one that eliminated ghosting entirely. Measured magnification was an exact 2X both with a single eyepiece and with the extended light path of a binoviewer.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\"It appears to be very well built. It is shown here flanked by the 2.5X GSO barlow and the TV 2X.\"\u003c\/strong\u003e\u003cbr\u003e— \u003ca href=\"https:\/\/www.cloudynights.com\/forums\/topic\/873637-new-astro-tech-2x-telecentric-extender\/?do=findComment\u0026amp;comment=12723279\"\u003eCloudy Nights AT 2X Telecentric discussion\u003c\/a\u003e. This owner photographed the AT telecentric alongside a GSO 2.5X and a TeleVue 2X Barlow, noting it was larger in diameter and slightly longer than the TeleVue, and heavier — a substantial piece of hardware for the price.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFour-element telecentric optical design.\u003c\/strong\u003e Two lens groups — a negative doublet and a positive pupil-correcting doublet — deliver a constant 2x magnification without the vignetting, exit pupil shift, or field distortion of a standard 2-element Barlow. The eyepiece behaves as if it were half the focal length, with no other optical compromises.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully multicoated optics.\u003c\/strong\u003e All air-to-glass surfaces are multicoated to maximize light transmission and minimize ghosting and internal reflections. Cloudy Nights users have noted the AT telecentric produces cleaner views than some considerably more expensive alternatives.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConstant 2x magnification.\u003c\/strong\u003e Unlike a standard Barlow, the telecentric design delivers a true 2x regardless of the distance between the Barlow lens and the eyepiece's focal plane. Your calculated magnification is your actual magnification — no guessing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTwo-piece design with 42mm T-thread.\u003c\/strong\u003e Unscrew the eyepiece holder section and the optical assembly exposes a 42mm T-thread for direct camera attachment. Use it visually with the full assembly, or photographically with just the optical section threaded onto your imaging train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilter-threaded nosepiece.\u003c\/strong\u003e Standard 1.25\" filter threads on the barrel let you stack a filter below the Barlow. Useful for planetary filters, light pollution filters, or solar filters in a white-light setup.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCNC-machined aluminum, anodized black.\u003c\/strong\u003e Not stamped or cast — machined from solid stock. The anodized finish is durable and the interior baffling is clean. This is a heavier, more substantial unit than a typical budget Barlow.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBinoviewer compatible.\u003c\/strong\u003e The constant 2x and clean light path make this a strong optical corrector assembly (OCA) alternative for binoviewers. The 42mm T-thread can attach directly to many binoviewer bodies with the right adapter, eliminating the nosepiece and saving weight.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25\" barrel with thumbscrew.\u003c\/strong\u003e Fits any standard 1.25\" focuser or visual back. The thumbscrew holds the Barlow firmly in place without requiring a compression ring.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eUnder the Night Sky\u003c\/h3\u003e\n\u003cp\u003eIn an 8\" f\/6 Dobsonian (1200mm focal length), drop in the AT2XTB with a 13mm eyepiece and you're at 185x — ideal planetary magnification for a night of average seeing. Jupiter shows its cloud belts and the Great Red Spot with clean contrast. Saturn's Cassini Division snaps into view. The four-element design means you're not trading sharpness for that magnification the way you would with a cheap Barlow.\u003c\/p\u003e\n\u003cp\u003eIn a 4\" f\/7 refractor, the 2x telecentric turns a 21mm wide-field eyepiece into a 10.5mm equivalent — a 53x view becomes 107x, and the sky background darkens noticeably. Globular clusters that were fuzzy blobs at low power start resolving into individual stars at the edges. The Orion Nebula's Trapezium splits cleanly. Because the telecentric doesn't shift the exit pupil, your wide-field eyepiece still feels comfortable at the higher magnification — no tunnel vision, no blackouts.\u003c\/p\u003e\n\u003cp\u003eFor imaging, unscrew the eyepiece holder and thread the optical section directly onto your camera's T-ring or a ZWO ASI camera's 42mm thread. Your 700mm f\/7 refractor becomes a 1400mm f\/14 setup — enough focal length for planetary imaging with a high-speed camera, or for resolving tight double stars photographically.\u003c\/p\u003e\n\u003ch3\u003eObserving Tip\u003c\/h3\u003e\n\u003cp\u003eIf you own a set of parfocal eyepieces — like the AT UWA 82° series — the 2x telecentric doubles your focal length coverage without breaking parfocality. Your 28mm becomes a 14mm equivalent, your 13mm becomes a 6.5mm, your 10mm becomes a 5mm. That fills the gaps in your eyepiece set without buying additional eyepieces, and you can swap between barlowed and unbarlowed views without refocusing. Keep the telecentric loaded in the focuser and swap eyepieces on top of it — the magnification is always a predictable 2x.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eHow is this different from a regular 2x Barlow?\u003c\/strong\u003e\u003cbr\u003eA standard Barlow uses a single negative lens group (typically 2 elements) that diverges the light cone. It works, but it shifts the exit pupil, can cause vignetting with wide-field eyepieces, and its magnification changes depending on the spacing between the Barlow lens and the eyepiece. A telecentric extender adds a second positive lens group (for a total of 4 elements) that corrects the exit pupil back to its original position. The result is a constant 2x magnification, no vignetting, and no change to the eyepiece's eye relief or apparent field characteristics.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I use this for astrophotography?\u003c\/strong\u003e\u003cbr\u003eYes. Unscrew the eyepiece holder section to expose the 42mm T-thread. Attach a T-ring for your DSLR or mirrorless camera, or thread on a dedicated CMOS\/CCD astronomy camera directly (most have 42mm T-threads built in). This doubles your telescope's focal length for planetary, lunar, and double star imaging.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes this work with a binoviewer?\u003c\/strong\u003e\u003cbr\u003eYes, and it's one of the stronger use cases for this product. The constant 2x magnification means the longer light path through the binoviewer doesn't shift the magnification the way it would with a standard Barlow. You can also unscrew the top section and use an M42-to-1.25\" adapter to attach the optical section directly to the binoviewer body, saving weight and nosepiece length.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill this vignette with wide-field eyepieces?\u003c\/strong\u003e\u003cbr\u003eThe telecentric design specifically addresses the vignetting problem of standard Barlows. Because it corrects the exit pupil back to its original position, the light path entering the eyepiece is the same as it would be without the Barlow — just at twice the magnification. Users report no vignetting even with 82° apparent field eyepieces.\u003c\/p\u003e\n\u003ch3\u003eAccessories\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAstro-Tech UWA 82° Eyepiece Series:\u003c\/strong\u003e Parfocal wide-field eyepieces in 16mm, 13mm, 10mm, and 7mm. Pair with the 2X telecentric to fill the gaps between focal lengths — a 13mm becomes a 6.5mm, a 10mm becomes a 5mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25\" Eyepiece Filters:\u003c\/strong\u003e The filter-threaded nosepiece accepts standard 1.25\" filters. A #80A blue filter sharpens Jupiter, a #23A red helps Mars, and a variable polarizing filter tames the Moon.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eT-Ring for your camera:\u003c\/strong\u003e Required for DSLR and mirrorless astrophotography. Thread it onto the 42mm T-thread after removing the eyepiece holder section. Available for Canon, Nikon, Sony, and other mounts.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFinal Thoughts\u003c\/h3\u003e\n\u003cp\u003eThe math on a 2x Barlow is simple: every eyepiece you own becomes two. But the math only works if the Barlow doesn't degrade the view on the way through. Budget 2-element Barlows compromise — vignetting, ghosting, wandering magnification, altered eye relief. The TeleVue Powermate solved those problems years ago with a 4-element telecentric design, but it costs several times more. The AT2XTB brings that same optical approach — four elements, constant 2x, corrected exit pupil — to a price that makes it a practical purchase rather than a long debate. If you've been using a shorty Barlow and wondering why the view isn't quite as clean as it should be, or if you've been avoiding Barlows entirely because of past experience, this is the one that changes the calculation.\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%;\"\u003eMagnification\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e2x (constant — telecentric design)\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%;\"\u003eBarrel Size\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e1.25\"\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%;\"\u003eOptical Design\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e4 elements, fully 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%;\"\u003eConstruction\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eCNC-machined aluminum, anodized black\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 Thread\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003e42mm T-thread (exposed when eyepiece holder removed)\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 Threads\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eStandard 1.25\" (nosepiece)\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%;\"\u003eEyepiece Retention\u003c\/td\u003e\n\u003ctd style=\"padding: 10px 14px; border: 1px solid #cccccc;\"\u003eThumbscrew\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":41465496928329,"sku":"AT2XTB","price":59.95,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0573\/7974\/9961\/files\/image_81cc3251-3584-434a-ac1c-b17f74fd6764.jpg?v=1717153777"}],"url":"https:\/\/astronomics.com\/collections\/barlows.oembed?page=2","provider":"Astronomics","version":"1.0","type":"link"}