Sharpstar 3" Quadruplet 0.85x Reducer / Coma Corrector for f/3-f/6 Newtonian Reflectors
Sharpstar 30085NTRD coma corrector can shorten the original focal ratio of f/4 to f/3.4, greatly shortening the exposure time. Besides, the Sharpstar 30085NTRD coma corrector is considerately designed with many threads. At the front of the corrector, there is M82×1 male thread for the connection to our 3" focuser. At the back of the corrector, there is tapped with M76×1 male thread, M68×1 female thread and M54×0.75 female thread, which can be used to thread on our M54 to M48 camera adapter ring. The back-focus is standard 55mm, starting from the M54 thread(camera end) to focal plane.