Description
Askar provides a F3.9 full frame reducer for FRA400 Astrograph, further reducing the focal length and thus shortening the exposure time on its original 400 focal length and f/5.6 focal ratio design basis. The reduction factor is 0.7×, and the reduced focal length is 280mm, which can satisfy most deep-sky astrophotography. The back focus is standard 55mm. The reducer has built-in M48×0.75 thread, easy for the attachment of 2″ filters.
Explore more from our collection.
Reviews
There are no reviews yet.