| 摘要 |
PURPOSE:To improve the operability of a camera by providing a focus and fade means which changes the occupying position of a lens for focusing according to the stop value of a photographing optical system. CONSTITUTION:The optical image of an object is formed on an image pickup element 34 by lens groups 20, 22 and 24 and converted to an electric signal. The quantity of incident light is detected by a stop control circuit 38 based on the output of the element 34 and a diaphragm 30 is controlled. The stop value of the diaphragm 30 is detected by an encoder 32 and supplied to a CPU 48. By a focusing detection circuit 36, it is detected based on the output of the element 34 whether the photographing optical system is under a focusing state or not and the detected result is supplied to the CPU 48. By the CPU 48, the moving quantity DELTAA of a focusing lens required for obtaining a prescribed out-of-focus quantity at the focal distance and the stop value when a focus and fade switch 50 is depressed is decided. Then, the lens group 20 is moved as much as the moving quantity DELTAA by a driving circuit 46 and a focus motor 44. The moving speed that the lens group 20 is moved as much as DELTAA within a fixed time is decided by referring to a table in the CPU 48. |
