Remote control system for a camera external flash unit where flashing of the camera's own flash unit with a time interval between flashes is used to control the duration of the external flash, so that light levels are optimized

摘要

Flash control system has a diaphragm interval calculator for an external flash unit based on a lighting factor and a light signal control in the camera for generation of at 2 light signals with a time interval between them indicating the diaphragm interval. A light signal detector in the external flash detects the light signals and adjusts the flash duration dependent on the time signal interval. The light signals sent to the external flash are generated by flashing of the camera's own flash unit. Independent claims are made for an external flash unit and a camera using the above control system.