A lock knob under the focuser lets you lock in your photographic focus. 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. The focus knobs have ribbed gripping surfaces so they are easy to operate, even while wearing gloves or mittens in cold weather. This provides exceptionally precise image control during high magnification visual observing and critical CCD imaging. The right knob also has a smaller concentric knob with a 10:1 reduction gear microfine focusing ratio. 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.ĭual speed 2.5" rack-and-pinion focuser: The precision-made focuser has dual-speed focusing. The edges of the lenses are blackened to reduce internal reflections and further improve image contrast.ĭew shield: A self-storing retractable dew shield slows the formation of dew on the lens in cold weather to extend your undisturbed observing time. Internal light baffles: Contrast-enhancing knife-edge light baffles in the 114mm diameter optical tube provide truly dark sky backgrounds and high terrestrial contrast. 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. Virtually no reflection of your face will be seen. This can easily be seen by looking into the objective lens of the scope. All three lens elements are slow-polished for smooth surfaces, with less scattered light.įully 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. It uses an ED (Extra-low Dispersion glass) center element to reduce spurious color halos and fringing to vanishingly low levels. At the price, and for the exceptional performance, it is an absolute steal!ĮD apochromatic triplet refractor optics: 115mm (4.53") aperture, 805mm focal length, f/7 focal ratio. 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. The supplied 2" and 1.25" eyepiece holders use non-marring compression rings that won't scratch your eyepiece barrels. In addition, a built-in camera angle adjuster lets you fine-tune the composition of your astrophotos. The focuser can rotate a full 360° to put your camera or eyepiece in the most comfortable observing position. The finely-machined scope has a dual-speed 2.5" rack-and-pinion focuser with a microfine 10:1 fine-focusing ratio. These exceptional optics are even more impressive when you consider the package they come in. 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! 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. dual hinged split tube rings with a Vixen-style dovetail. ![]()
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