Automatic exposure control system for flash photography
    1.
    发明授权
    Automatic exposure control system for flash photography 失效
    用于闪光摄影的自动曝光控制系统

    公开(公告)号:US4083059A

    公开(公告)日:1978-04-04

    申请号:US717950

    申请日:1976-08-26

    IPC分类号: G03B15/05 G03B15/03

    摘要: In a camera provided with a day-light exposure range and with a flash exposure range, an automatic exposure control system for controlling the iris of the camera in accordance with a computed exposure value and a preselected shutter time is associated with a flash exposure time range bracketing device in order to insure that the formation of a correct flash exposure aperture is effected with automatic selection of one of the bracketed exposure times despite an accidentally incorrect setting of the shutter dial of the camera which may be encountered particularly when the day-light exposure range is to be left for the flash exposure range without the necessary manipulation of the shutter dial therefor. The bracketing device of the present invention comprises three timing circuits in combination with a selector responsive to the position of the shutter dial for selecting either the first, or the second, or the third timing circuit for cooperation with an electronic switch controlling the period of actuation of the camera shutter when the shutter dial is set either within, or on the faster side of, or on the slower side of a possible flash exposure time range respectively, whereby the resultant actuation period is equal to either the shutter time preselected on the shutter dial, or the faster limit of, or the slower limit of the flash exposure time range respectively.