| 摘要 |
A shutter operating mechanism with an electrically controlled shutter has three modes of operation, namely an automatic mode in which the rate of opening of the shutter is controlled by a governor and the exposure time is controlled by a photocell sensing the brightness of the subject being photographed, a semiautomatic mode in which the aperture is set manually and the exposure time is controlled according to the setting for the aperture and the brightness of the subject, and a nonautomatic mode in which both the aperture and exposure time are set manually. Selection is made by concentric rings for controlling aperture and exposure time respectively. Each of the rings can be set for automatic operation or for a selected value.
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