Abstract

A system for detecting the brightness of an area which is to be photographed. A plurality of series circuits respectively include a plurality of photosensitive devices for respectively receiving light from different parts of the area while remaining substantially static with respect thereto so that when the area is illuminated unevenly a pair of the photosensitive devices will respectively receive light of maximum and minimum brightness. The plurality of series circuits respectively include also a plurality of series-connected elements respectively connected in series with the plurality of photosensitive devices for respectively providing therewith a plurality of photo-responsive divided voltages. The plurality of series circuits are connected in parallel with each other and with a power source. A reference voltage unit provides between given upper and lower limits a reference voltage progressing between these limits, this reference voltage means including at least one variable resistor and also being connected in parallel with the plurality of series circuits. A comparing circuit is electrically connected between the plurality of series circuits and the reference voltage unit for comparing the photo-responsive voltages with the reference voltage, with an indicator means being provided to indicate when one of the above pair of photosensitive devices provides a photo-responsive voltage having a predetermined relationship with respect to the reference voltage.