The Askar 65PHQ 0.75x full-frame reducer features a quadruplet design specifically optimized for the 65PHQ. The 0.75x reduction shortens the focal ratio to f/4.8 and focal length to 312mm, effectively shortening exposure time and dramatically increasing your field of view. Standard 55mm back focus from M48 thread with M54 and M48 adapters included, plus built-in M48×0.75 2" filter thread.