Shutter-priority automatic exposure camera

摘要

A camera operable in shutter-priority automatic exposure mode comprises a photometric circuit, an exposure data memory circuit for storing information on a plurality of selectable diaphragm openings, and a control circuit for calculating a desirable diaphragm opening based on a shutter speed preset prior to an exposure and luminance data output from the photometric circuit, and determining an actual diaphragm opening based on a comparison between the calculated diaphragm opening and the selectable diaphragm openings. The control circuit checks whether the preset shutter speed is higher or lower than a predefined reference shutter speed and selects one of the selectable diaphragm openings that provides a higher shutter speed if the preset shutter speed is higher than the reference shutter speed, or selects one of the selectable diaphragm openings that provides a lower shutter speed if the preset shutter speed is lower than the reference shutter speed.