Abstract: There is disclosed herein an electronic system and method for metering the incident light on a subject being photographed, some or all of which light emanates from an electronic flash unit, and for storing an incident light value for use in controlling the electronic flash unit during the taking of subsequent photographs of the subject. An exemplary system includes a remote light sensor which can be placed at or near the subject being photographed for measuring the light incident on the subject during a "test flash" from the electronic flash unit so as to enable the storage of an incident light value. This incident light value may comprise a signal representing the duration of the flash or a signal proportional to the drop in energy of the supply source of the electronic flash unit, both of which are proportional to the quantity of incident light.