Abstract: A control system for a camera controls a shutter release operation electromagnetically. A signal generating circuit produces a switching signal for operating a switching circuit which supplies current to a control circuit for a camera. The signal generating circuit is in a condition to always produce a switching signal when a camera operation member is set to normal photographing modes other than the bulb photographing mode, and is out of condition to produce the switching signal during the time between actuation of a magnet and termination of the shutter opening operation. The closing operation of the shutter is checked by means of a mechanical control member during the release when the camera operation member is set in the bulb photographing mode.

Abstract: A photometric circuit for a camera including a first operational amplifier with a photo-electric element connected between its inverted and non-inverted input terminals and, a logarithmic compression diode connected between the output terminal and the inverted input terminal of the first operational amplifier, thus providing a voltage corresponding to the logarithmic value of the brightness of an object to be photographed at the output terminal of the first operational amplifier.A second operational amplifier has a plurality of temperature compensating commonly polarized diodes connected in parallel between its inverted input terminal and the output terminal. A first constant voltage is applied to the non-inverted input terminal of the second operational amplifier while a second constant voltage is applied through a resistor to the inverted input terminal of the second operatonal amplifier, thereby providing temperature-compensation of the output voltage of said first operational amplifier.