Abstract: An SLR camera includes a light measuring and computing circuit 1-7 whose output is fed to a comparator 8 together with the analog output of a D/A converter 12 coupled to a bidirectional counter 13. The counter is servo-loop driven to achieve circuit balance through AND gates 10, 11 in response to the comparator outputs, and the decoded counter outputs energize an appropriate LED display element L1-L16. The AND gates are disabled by the closing of switch 17 in response to the raising of the reflex mirror, to thereby lock the counter and display and prevent fluctuations therein. A capacitive time delay may be provided after the reopening of the switch following the lowering of the mirror to allow circuit transients to settle out.

Abstract: A circuit is disclosed for controlling the drive motor of a motor driven camera in a single frame shot mode, A continuous shooting mode and a bulb mode. The circuit includes provision for controlling the camera from a plurality of positions. A release circuit controls the motor until the shutter is released. Then a film winding circuit controls. The time constant of the film winding circuit may be varied to control the duration between successive shots in a continuous shot mode. For a single shot mode, the film winding circuit is effectively blocked from operating the motor until the release button is no longer depressed.