Exposure measuring circuit

摘要

The aim and object of the invention is to improve the yield of correctly exposed photographs despite periodic changes in subject brightness during the exposure measurement phase and despite the application of a non-lagging photoreceiver by means of a circuit which is provided with an integrating unit and which makes said changes in brightness known on a warning display or automatically takes them into account when calculating the exposure parameters. The existing object is achieved when the time constant of the integrating unit can be varied in proportion to an exposure time formed in the exposure control circuit and a non-integrated alternating signal component is fed to a warning display in the case of automatic cameras or to a shutter control unit in the case of programmed cameras. <IMAGE>