| 摘要 |
PURPOSE:To improve the responsiveness and the control accuracy in a still mode and a movie mode by bringing a diaphragm to a driving control to a position where a photometric value reaches a correct exposure value, only in case a state that the photometric value has been shifted from the correct exposure value has continued N times. CONSTITUTION:A diaphragm driving mechanism is constituted of a stepping motor 38 for adjusting an aperture of a diaphragm and a stepping motor driving circuit 36, an operation/exposure control circuit 32 has a pulse generating function for driving the stepping motor 38, and in accordance with a timing pulse outputted from a timing pulse generating circuit 50, the operation/exposure control circuit 32 executes a photometry and a diaphragm driving control. That is to say, a deviation DELTAL of a photometric value and a correct exposure value calculated, based on the photometric value is calculated, and in case when DELTAL is negative, in case it is decided that the counting contents of a counter does not reach N, the same processing is repeated. In such a way, even if the responsiveness of a control system to the photometric value is raised so as to be suitable for photographing by a still mode, a comparatively slow diaphragm control can be executed at the time of a movie mode.
|
