Astro-Tech 0.8x Reducer/Flattener for AT115EDT Refractor (V3) – AT115EDTRFv3
Tailored for full-frame astrophotography, the Astro-Tech AT115EDTRFv3 reducer/field flattener is designed specifically for the AT115EDT f/7 ED triplet apo refractor with the 3.2" focuser. This third-generation model delivers a wider, flatter, faster field—perfect for deep-sky imagers looking to maximize the potential of their 115mm Astro-Tech refractor.
Built to Match the AT115EDT—No Guesswork Required
The AT115EDTRFv3 isn’t a generic reducer—it’s purpose-built to pair perfectly with the Astro-Tech AT115EDT. Threading directly into the M92 drawtube of the 3.2" focuser, it reduces your telescope’s native focal length from 805mm at f/7 to a faster, flatter 644mm at f/5.6, while correcting the field curvature across a full-frame image circle.
Full-Frame Compatibility with Edge-to-Edge Sharpness
Whether you’re using a DSLR, a dedicated astronomy camera, or a full-frame mirrorless sensor, this reducer/flattener keeps your stars tight and round across the entire field. No more field curvature at the edges, no more corner coma, and no need to crop your image down to a usable core. Your AT115EDT becomes a precision astrograph with a true imaging sweet spot that fills the frame.
Versatile Threading and Internal Filter Support
The camera side of the AT115EDTRFv3 gives you the same flexible threading options as its larger sibling:
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M78x1 female
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M54x0.75 male
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M48x0.75 male
And if you want to add a 2" filter without the hassle of a filter drawer or wheel? Just unscrew the top optical cell to reveal a built-in 2" filter thread, allowing inline use of light pollution, narrowband, or LRGB filters—without complicating your imaging train.
Precision Coatings, Thoughtful Engineering
This reducer/flattener is fully multi-coated for maximum light throughput and minimal internal reflections. Threaded covers are included for both ends to protect your optics when not in use. And the standard 55mm back focus from the shoulder of the reducer to the image plane ensures compatibility with common T-rings, spacers, and off-axis guiders.
Observing Tip
Pair this reducer/flattener with a one-shot color camera and a dual narrowband 2" filter for a powerful, portable imaging setup. You’ll be able to capture vivid hydrogen-alpha and oxygen-III emission from bright nebulae like the Heart, Soul, and Elephant Trunk—without the need for a filter wheel.
Final Thoughts
Whether you’re a seasoned imager or just stepping up from basic setups, the AT115EDTRFv3 is the optical upgrade your AT115EDT was waiting for. Speed up your exposures, sharpen your corners, and streamline your imaging train with a reducer that was designed from the ground up for your scope. The sky doesn’t wait—neither should you.
