External flash control system

摘要

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.