Astro-Tech Dedicated 0.8x Reducer/Field Flattener for the AT80ED Refractor (#AT80EDRF)
If you own an Astro-Tech AT80ED refractor and are ready to step into astrophotography, this dedicated 0.8x reducer/field flattener is the upgrade your setup needs. Designed specifically for the AT80ED (model year 2018 and newer), the Astro-Tech AT80EDRF turns your visual refractor into a flat-field, wide-field astrograph—perfect for DSLR and mirrorless camera imaging.
Built Just for the AT80ED
Unlike generic reducers or flattener systems that only approximate your scope’s optical characteristics, the AT80EDRF is precision-matched to the native focal length and field curvature of the Astro-Tech AT80ED. It threads securely into the 2" focuser and sits exactly where it belongs—ensuring consistent results with minimal fuss.
Faster Speed. Wider Field. Sharper Corners.
The reducer drops your focal length from 560mm to 448mm, reducing your f/ratio from f/7 to f/5.6—a welcome bump in speed that allows shorter exposures and a significantly wider field of view. That makes it an ideal choice for framing large nebulae, wide star fields, and extended galaxy groups.
But speed alone isn’t enough. The AT80EDRF also flattens the inherent field curvature of your refractor so that stars remain tight and round. This however is not designed to work well with full frame sensors. You will still get curvature if you use a large chip.
Easy Setup, Solid Compatibility
The telescope-side barrel of the AT80EDRF is a standard 2" insert that slides directly into the AT80ED’s focuser. It's also threaded for 2" filters, so you can add a light pollution or dual narrowband filter inline without adapters or filter drawers.
The camera-side has standard M42 T-threads, allowing quick connection to your DSLR or mirrorless camera using a standard T-ring. The reducer is optimized for 55mm of back focus from the reducer’s shoulder to the imaging plane—matching the standard spacing for most DSLR systems.
Observing Tip
Add a 2" light pollution filter directly into the reducer body before you begin imaging—no filter drawer needed. This is especially handy if you’re shooting emission nebulae from a suburban backyard where a narrowband or UHC filter can make all the difference in your image contrast.
Final Thoughts
A good reducer/flattener should do three things: make your images faster, flatter, and easier. The Astro-Tech AT80EDRF does all three, and it does them well—without the guesswork or frustration of generic optics. If you're ready to take the next step with your AT80ED, this is the right tool for the job.
