| 摘要 |
PURPOSE:To prevent the wasteful consumption of electric energy by causing preliminary emission of a flash discharge tube, measuring the light from an object illuminated by this emission through a photographic lens aperture and stopping the emission of the flash discharge tube upon determination of the aperture. CONSTITUTION:A signal commanding preliminary emission is sent from a camera to a flash device, and when the photometric value outputted by the photometric circuit in a control signal generating circuit 1 incorporated in the camera attains the prescribed relation with respect to a value given beforehand, the signal for detaining the stopping-down movement of the aperture via an aperture diameter control circuit 4 is emitted, and with this signal as a preliminary emission stop signal, it is sent to the flash device through the flash control circuit 8 of the camera. with such constitution, the sustained emission of the flash discharge tube is stopped upon determination of the aperture and therefore the wasteful consumption of electric energy by the subsequent wasteful emission of the discharge tube is prevented. |
