Astro-Tech .8X Reducer Field Flattener For The 72EDII Optical Tubes
Manufacturer Part # ATRF72
While this Astro-Tech ATRF72 0.8X reducer/field flattener is designed for prime focus astrophotography with the Astro-Tech AT72EDII, it will work with other variants of the same optical tube. Feel free to give us a call if you have a question about your scope if it isn’t an Astro-Tech product. 800-422-7876
The fully-multicoated Astro-Tech ATRF72 converts the 430mm focal length f/6 Astro-Tech AT72ED refractor into a 344mm f/4.8 lens 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 ATRF72 flattens the normal field curvature inherent in all refractors to provide images that are sharply focused out to the very corners of a large format DSLR chip. 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 ATRF72 reducer/flattener threads on the 72EDII focusers. The flattener is threaded for attachment to the telescope via a 54mm metric thread. The camera side of the reducer has 48mm T-threads to connect to a T-ring and camera body. Back focus is 55mm from the shoulder of the reducer to the image plane, the standard spacing for 35mm and DSLR camera bodies.
The interior of the telescope side of the reducer/field flattener is a 48mm female thread so standard 2" filters can thread right in.