Exposure control system for flash photography - has timer controlling duration of flash in response to camera-to-object distance set with focusing adjustment

摘要

The flash exposure control system comprises a flash lighting unit to energise the flash lighting unit during an exposure. A switch connected to the flash lighting unit controls the termination of energisation of the flash lighting unit. A timer controls the conduction of the switch and has an adjustable circuit for adjusting the duration of conducting time as a function of the camera-to-object distance. The adjustable circuit is responsive to the camera focus adjustment. An aperture adjusting unit is responsive to the focus adjustment for defining an exposure aperture.