Abstract: A camera shutter that has an electronic timing device and a photo-electric resistor and associated capacitor timing circuit; a charge starting contact is actuatable to commence the timing circuit action, and an electro-magnetically actuated locking device energized by the timing circuit to hold the shutter blade system open for the duration of the exposure time as determined by the photo-electric resistor. In addition, a mechanical device is provided which acts to delay the opening movement of the driving mechanism of the shutter blade system after actuation of the contact by an amount to compensate for the time taken by the electro-magnetic locking device to move to an unlocking position after the magnet thereof is de-energized by the timing circuit.