| 摘要 |
PURPOSE:To automatically correct the shift of focus by calculating a moving extent of a lens for focusing so as to offset the shift of a focus generated by a movement of a lens for soft. CONSTITUTION:A photographic lens 1 is constituted of a lens 1-1 for focusing for adjusting a focus by a movement in the optical axis direction and a lens for soft for obtaining selectively normal, soft 1 and soft 2 by a movement in the optical axis direction, sets the driving quantity of a range ring corresponding to a variation of a state of a soft switch 16, and drives the range ring in accordance with its set value. After the driving has been ended, setting of the range ring driving quantity and driving corresponding to a variation of a state of the soft switch 16 are repeated again. As for the focal shift at the time when the state of the soft switch 16 has been varied, the state of the soft switch of the present time and the state of the soft switch of the previous time are compared, and based on a table which has been set in advance, correction quantity is determined. |
