Exposure control system for a photographic camera

摘要

In a photographic camera with an automatic exposure control system, a voltage obtained by a light measuring circuit with reference to a reference voltage based on a film speed is divided into 1/n and (n-1)/n of the voltage. The scene brightness is measured while the diaphragm provided before a photosensor of the light measuring circuit is stopped down until the output voltage of the light measuring circuit becomes equal to 1/n of the voltage. After the output voltage has become 1/n of the voltage, the diaphragm is held in its position and then the shutter speed is controlled according to the (n-1)/n voltage.