PURPOSE: To obtain highly accurate shutter operation over the entire brightness range by providing a control switching means which selects control by a 1st or 2nd drive control means according to an Ev value which is predetermined at the time of photography.

CONSTITUTION: A control circuit 3 drives a light measuring circuit 1 with the signal from a release signal generating circuit 2 to detect brightness information on a subject. Then the Ev value at the time of the photography is obtained according to the brightness information and the sensitivity of a film in use and it is discriminated according to the Ev value whether a shutter is released under constant-speed control by the constant voltage control of a voltage control circuit 4 or by turning a motor on and off by applying a source voltage directly to a motor driving circuit 6. Then the number of reference pulses corresponding to the open-aperture diameter of a shutter blade is operated from the Ev value. A control circuit 3 switches and connects a changeover switch 5 to an upper or lower contact shown in the figure with a switching signal (e) according to the shutter releasing speed needs to be brought under the constant speed control by the voltage control circuit 4 or directly from the power source.