The Astro-Tech AT115EDT 4.53" f/7 ED triplet apochromatic refractor offers more performance and features than similarly-priced smaller aperture competitive refractors and a markedly lower price than competitive scopes with the same aperture. All in all, an exceptional value.
This new Astro-Tech AT115EDT refractor has:
• 115mm f/7 fully multicoated triplet apochromatic optics using an ED center element
• a dual-speed 2.5" rack-and-pinion focuser with 10:1 ratio fine focusing
• a soft sided carry case
• a rotatable focuser
• a camera angle adjuster
• retractable lens shade/dew shield
• dual hinged split tube rings with a Vixen-style dovetail
With an aperture of 115mm (4.53"), this Astro-Tech AT115EDT ED triplet apochromatic refractor gathers over 27% more light than the more common size (and often similarly-priced) 102mm refractors. Combine this extra light gathering with the Astro-Tech AT115EDT's slow-polished triplet optics and state-of-the-art optical multicoatings, and you have a scope that outperforms similar (but more costly) competitive 102mm and 110mm refractors - and at a price as much as $700 less than a similar competitive scope!
These exceptional optics are even more impressive when you consider the package they come in. The finely-machined scope has a dual-speed 2.5" rack-and-pinion focuser with a microfine 10:1 fine-focusing ratio. The focuser can rotate a full 360° to put your camera or eyepiece in the most comfortable observing position. In addition, a built-in camera angle adjuster lets you fine-tune the composition of your astrophotos. The supplied 2" and 1.25" eyepiece holders use non-marring compression rings that won't scratch your eyepiece barrels.
This feature-laden 115mm Astro-Tech ED triplet apochromatic refractor offers more aperture for the same price as competitive triplet APOs, and is priced hundreds of dollars less than competitive scopes with the same aperture. At the price, and for the exceptional performance, it is an absolute steal!
Features of this Telescope . . .
ED apochromatic triplet refractor optics: 115mm (4.53") aperture, 805mm focal length, f/7 focal ratio. It uses an FK-61 ED (Extra-low Dispersion glass) center element to reduce spurious color halos and fringing to vanishingly low levels. All three lens elements are slow-polished for smooth surfaces, with less scattered light.
Fully multicoated optics: The triplet objective lens has the latest state-of-the-art antireflection multicoatings on all air-to-glass surfaces for high-light transmission and excellent contrast. This can easily be seen by looking into the objective lens of the scope. Virtually no reflection of your face will be seen. It's a sure sign that the high transmission coatings are doing their job, by letting virtually all the light enter the scope, rather than reflecting some light back to your eye.
Internal light baffles: Contrast-enhancing knife-edge light baffles in the 114mm diameter optical tube provide truly dark sky backgrounds and high terrestrial contrast. The edges of the lenses are blackened to reduce internal reflections and further improve image contrast.
Dew shield: A self-storing retractable dew shield slows the formation of dew on the lens in cold weather to extend your undisturbed observing time. It also improves the contrast, similar to the effect of the lens shade on a camera lens, when observing during the day or when there is excessive ambient light at night, such as from a neighbor's backyard security light.
Dual-speed 2.5" rack-and-pinion focuser: The precision-made focuser has dual-speed focusing. There are two coarse focusing knobs. The right knob also has a smaller concentric knob with a 10:1 reduction gear microfine focusing ratio. This provides exceptionally precise image control during high-magnification visual observing and critical CCD imaging.
The focus knobs have ribbed gripping surfaces so they are easy to operate, even while wearing gloves or mittens in cold weather. The focuser drawtube has 75mm of travel and a millimeter scale on the drawtube to let you return to an approximate focus when switching between visual and photographic setups. A lock knob under the focuser lets you lock in your photographic focus.
The 2.5" focuser can be rotated a full 360° to line up a camera in either a landscape or portrait orientation (or any orientation in between), as well as put a star diagonal and eyepiece into the most comfortable observing position. Simply loosen the knob on the top of the focuser housing, rotate the focuser to whatever angle is most convenient for you, and then tighten the knob to lock the focuser at the desired angle.
Built-in camera angle adjuster: In addition to the entire focuser rotating, the focuser drawtube's 2" eyepiece/accessory holder includes a built-in camera angle adjuster that lets you quickly make final small adjustments tweaks to the angle of your camera or star diagonal without having to disturb the heavier focuser proper. This camera angle adjuster is standard equipment, not an optional extra-cost accessory, as it is with some other scopes.
A knob on the 2" eyepiece/accessory holder lets you unlock the accessory holder, rotate it to the desired final angle, then lock it in place at whatever angle is most convenient for you. Many observers will find this camera angle adjuster to be even more convenient than the focuser rotation system and will use this method of adjusting the viewing angle exclusively.
Compression ring eyepiece holders: The focuser's 2.5" drawtube terminates in a 2" eyepiece holder that uses a non-marring compression ring to hold a 2" star diagonal and/or accessories in place. The compression ring won't scratch the barrel of your star diagonal and accessories as an ordinary thumbscrew can.
A supplied 1.25" accessory adapter slips into the 2" eyepiece holder to let you use a 1.25" star diagonal, image erecting diagonal, or photographic accessories. Like the 2" eyepiece holder, the 1.25" adapter also uses a non-marring compression ring to hold 1.25" star diagonals and accessories in place.
Optical tube: The 27.25" long optical tube and focuser (32.4" long with lens shade extended) are finished in a durable white powder-coated finish, with grey anodized trim. There is a finderscope mounting shoe that accepts Vixen-style finderscope mounting brackets. The shoe can be mounted on either the top left or top right side of the focuser body. A slip-on metal dust cap is standard, as is a dust seal for the eyepiece holder.
Tube rings and dovetail: Dual split hinged tube rings are supplied for the 114mm o. d. optical tube. The rings are lined with white felt that will not stain the white finish of the scope over time, unlike the black felt supplied with other scopes. A Vixen-style dovetail is bolted to the tube rings. Optional Losmandy-style D-plate dovetails are available if your mount uses a wider Losmandy-style saddle.
Soft Carry Case: The scope comes standard in a heavy-duty nylon carry case. The case has some nice pockets in the lid for paper storage as well as 7 different cutouts in the foam for accessory storage.
