| 摘要 |
PURPOSE:To improve the exposure accuracy for an automatic exposure control by compensating an error quantity generated at every different kind of lens by the quantity of a motion of an operating system at the time of executing a stopping-down operation toward a lens side from a camera body side. CONSTITUTION:The quantity corresponding to a difference which a full-aperture diaphragm value being different at every interchangeable lens, an illuminance error of a film surface generated in its full-aperture diaphragm value, and an illuminance error generated in relation to a position of a light receiving part have against a full- aperture diaphragm value of a reference lens and these errors is corrected by being replaced with the pre-running quantity which is not concerned in a light quantity control effect by stopping-down, by a release plate 3 for relaying an operation of a diaphragm driving member of a camera body side controlled by an operation of an exposure controlling circuit, to a diaphragm blade S of the lens side, and also, a diaphragm blade stop error corresponding to a delay of an operation generated due to a mechanism of an operating system for relaying the operation of the diaphragm driving member to the diaphragm blade S is added to the pre-running quantity and corrected. In such a way, a stopped-down operation of extremely high accuracy and an exposure control of high accuracy thereby can be executed.
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