A flash control system remotely controls an external flash by a camera. In
the camera, a stop value is calculated as a photographic exposure factor
for the external flash, and a flash-light emission timing of the external
flash is calculated. A built-in flash of the camera is controlled to emit
two light signals at a time interval representing the stop value. The
external flash detects the two light signals. A timing of a flash-light
emission of the external flash is controlled in accordance with one of the
two light signals. An amount of the flash-light emission of the external
flash is controlled in accordance with the time interval.