Electronic apparatus for controlling an adjustable part of a photographic camera. The control arrangement is set into operation by an electric impulse, produced by movement of a manually movable member to initiate the control operation. In one embodiment (FIGS. 1-14), the initiating electric impulse serves to activate a resistance bridge which comes into balance and stops further movement when a movable adjustable part on the camera reaches a position corresponding to that of a manually movable member on a control box, which may be located at a point remote from the adjustable part on the camera. In this embodiment, the adjustable part on the camera may serve to adjust a diaphragm aperture, or a shutter speed control member, or a focusing member. In a second embodiment (FIGS. 15-17), the initiating electric impulse serves to activate transistorized electronic circuitry which controls the extent of a first exposure delay period (prior to opening the shutter blades) and also the extent of a second exposure delay period while the blades are open, thus determining the duration or speed of the exposure.