Compensation for diaphragm control in SLR camera

摘要

A camera has first and second displaceable actuators and a diaphragm adjustable between a maximum aperture value and a minimum aperture value responsive to displacement of the second actuator. A first signal is generated that is representative of the displacement of the first actuator. A second signal is generated that is representative of a desired aperture value of the diaphragm for correct exposure. A first and second signal are compared. The first actuator is displaced upon shutter release, but the second actuator remains stationary during an initial portion of the displacement of the first actuator and is displaced as a unit with the first actuator during the remainder of the displacement of the first actuator. When the first and second signals assume a predetermined relationship as indicated by the comparison, displacement of the actuators is arrested and the proper aperture value is provided. In a camera having interchangeable lenses, the first actuator is disposed in the camera body so that none of the parts of the first signal generator need to be placed in the lens.