| 摘要 |
PURPOSE:To speed up an operation time required for focus detection by making an arithmetic range in which the 1st and 2nd signals are relatively displaced narrower than a normal arithmetic range after the 2nd frame of continuous photographing in a continuous photographing mode. CONSTITUTION:Since it is expected in the continuous photographing mode that focus detection should be executed within a short period shorter than that of a single photographing mode and the change of defocusing value of an object is not generated so much, a relative displacement value (kc) in a comparatively small arithmetic range, i.e. k1=-kc and k2=kc, is set up to speed up the arithmetic operation. Since a range for the execution of correlative operation, i.e. the arithmetic range, is reduced at the continuous photographing mode, the time required for the focus detecting processing is shortened and focus detection corresponding to high speed continuous photographing can be attained. Since operation similar to normal photographing (single photographing) is executed in the 1st frame of the continuous photographing and the size of the range to be displaced is set up to the relative displacement value (kc) in the 2nd frame and after, probability generating the failure of focus detection is reduced. |
