Automatic exposure control device for single lens reflex camera

摘要

An automatic exposure control device for a single lens reflex camera characterized in that a stop determining member which stops down diaphragm blades by rotation thereof at a predetermined speed is released by a shutter release plate. A time constant circuit is started to operate simultaneously with the start of rotation of said stop determining member, and the rotation of said stop determining member is stopped by an electromagnetic mechanism when a time has lapsed. The length of said time linearly corresponds to the stop size determined by APEX operation based on the output voltage of said time constant circuit as an operation factor.