| 摘要 |
PURPOSE:To always catch a shutter chance by operating a follower means although only two focusing detections are performed if a release request is issued. CONSTITUTION:On receiving a focusing signal DF from a focus detecting means 1, a focusing storage means 2 issues the defocus quantity DFa of this time and that DFb of preceding time. A focusing deciding means 3 decides focusing or not, and a lens driving means 4 drives a lens to a focal point. A release request deciding means 6 decides a release request through a release button 5, and a moving speed calculating means 7 calculates the moving speed of an object with the aid of the signals DFa and DFb. A following operation means 8 supplies a lens driving signal so as to focus the lens on the object at the moving speed. A following operation deciding means 9 permits following if a release request is issued when the defocusing directions of the signals DFa and DFb are the same and not focused. Under this constitution, algorithm for following operation is modified whether a release request is present or not,so that a photographer never misses a shutter chance. In case of photographing a moving object, focusing accuracy can be improved. |
