Pressing of the camera release button causes start of the film transport and automatic setting of the diaphragm for a normal exposure. When fade-over switch is closed, a forward-reverse counter is started. When the count on the counter reaches 31, a first AND-gate switches a first JK flip-flop to a second state wherein an additional resistor is inserted in the normally balanced diaphragm control circuit thereby unbalancing same and causing the closing of the diaphragm to commence. When the count on the counter reaches 63, another AND-gate switches additional JK flip-flops for reversing both the film transport and the counting direction of the counter. When the counter has counted down to a predetermined number, further logic circuits cause a stoppage of the film transport and stopping and resetting of the counter so that reactivation of the release button automatically starts the fade-in.