Product Description
This Astro-Tech AT90CFTRF 0.8X focal reducer/field flattener is designed specifically for prime focus astrophotography with the Astro-Tech AT90CFT apo refractor.
The fully-multicoated Astro-Tech AT90CFTRF reducer/flattener converts the 540mm focal length f/6 Astro-Tech AT90CFT refractor into a 432mm f/4.8 system for faster and wider field astronomical and terrestrial photography.
In addition to reducing the focal length of the telescope and thereby increasing the photographic speed, the AT90CFTRF flattens the normal field curvature inherent in all refractors. This provides images that are sharply focused out to the corners of DSLR, CMOS, and CCD imaging chips. Stars look sharp and point-like all the way across the field in your images. You don't have to worry about photos that are sharp in the center and blurry at the edges.
The Astro-Tech AT90CFTRF reducer/flattener threads into the focuser, or camera angle adjuster for a secure connection. The threading is metric 63x1.
The camera side of the AT90CFTRF reducer has 48mm T-threads to connect to a T-ring and DSLR camera body. A slip-on soft rubber cover protects the T-threads when the reducer is not in use, while a second slip-on cover is provided for the 2" scope-side barrel. Back focus is 55mm from the shoulder of the reducer to the image plane, the standard spacing for DSLR camera bodies.
The top of the reducer/field flattener will unthread from the body exposing a 48mm filter holder on the underside of the cap that was just unthreaded. This will allow you to thread 2" filters into your imaging train.
Tech Details
| Weight | 9 oz. |
|---|---|
| Warranty | 1 year |