| 摘要 |
PURPOSE:To excel in the operability of manual focusing, and to execute the focusing with high accuracy even when the diameter of a focusing ring is large. CONSTITUTION:The variation of rotational angle of the focusing ring 2 per a specified time is detected based on the output of a rotation detector 3. A microcomputer 4 judges whether the variation of the rotational angle of the focusing ring 2 per the specified time is in the range of a threshold or not, and the gain of the moving speed of the focusing lens 5 with respect to the rotational angle of the focusing ring 2 per the specified time is set according to the judgment. Thus, the position of the focusing lens 5 can be largely moved and also the focusing with the high accuracy can be executed without turning the focusing ring 2 for several times. |
