Camera flash control with light meter - has blocking switch operating when flash unit is mounted and auto changeover from daylight to flash exposure

摘要

A camera has an indicator to show inadequate light conditions and triggers, by piezoelectric circuitry, a multiple flash unit. A blocking element switches off the circuitry when a multiple flash unit has been inserted. The immobilising switch is in parallel to the flash unit. The flash triggering is directly controlled by the light measuring circuitry with its associated LED indicator. Flash triggering is by a piezoelectric crystal and inductance.