Photographic camera having a diaphragm actuator with preliminary displacement for lens compensation

摘要

A camera has a displaceable actuator in a diaphragm adjustable between a maximum aperture value and a minimum aperture value responsive to displacement of the actuator. A first signal representative of the displacement of the actuator is generated. A second signal representative of a fraction of an exposure quantity dependant on film sensitivity and subject light is generated. Responsive to the second signal, the exposure time of the camera is set. At least partially responsive to the second signal, a third signal representative of the desired aperture value of the diaphragm for correct exposure is generated. The first and third signals are compared. Upon shutter release, the actuator is displaced and the diaphragm is maintained at the maximum aperture value during an initial portion of the displacement of the actuator to compensate for the characteristics of the particular interchangeable lens connected to the camera body. Responsive to the comparison, displacement of the actuator is arrested when the first and second signals assume a predetermined relationship, which establishes the desired diaphragm aperture value for correct exposure. The desired diaphragm value and shutter speed are also displayed.