Method and apparatus for the photographic camera with the aid of a lamp has eclair

摘要

A method and apparatus for controlling exposure in flash photography includes a first photocell positioned to receive light reflected from a scene that is illuminated by flash light and available ambient light and a second photocell positioned to receive only direct flash light. Once a flash lamp is energized, the effective lens aperture is progressively reduced in size until the instantaneous ratio of the output signal from the first photocell to the output signal of the second photocell falls below a predetermined value at which time the lens aperture is set and shutter opening movement is initiated. In one embodiment the shutter is closed at the end of a fixed time period. In a second preferred embodiment a light responsive integrating circuit is utilized to control shutter speed in accordance with the scene light impinging on the camera film exposure plane. With each of these embodiments, a maximum depth of field is achieved which takes into account ambient light and reflected flash light.