| 摘要 |
PURPOSE:To prevent out of focus by controlling an aperture value in such a way that is does not attain such an aperture value at which adverse influence is given to the accuracy of focusing detection, for example, at the time of operating an automatic focusing device with a mode of controlling the aperture value automatically. CONSTITUTION:Aperture regulating devices OP1, OP2, OP5, VR4, CP3, Mg1, C2, etc. which regulate the aperture of a lens automatically according to object luminances are provided and the 1st circuits OP3, CP1, G1, G3, S5 which operate so as to stop down he aperture value to a prescribed value when it is smaller than the value giving prescribed depth of field and shutter second time regulating devices Mg2, CC4, D4, D5, OP6, R5, C3, E3, S4 which regulate shutter second time according to the actually regulated aperture value and the depth of field are provided. The aperture value conforming to the accuracy of focus detection and focus control is selected atutomatically. With such constitution, out of focus is prevented. |
