| 摘要 |
PROBLEM TO BE SOLVED: To accurately maintain the best focusing position by automatically adjusting the position of a master lens at the time of zooming, at the time of switching an extender or even in the case a diaphragm is fluctuated. SOLUTION: This correcting method is provided with a focusing lens 12, a zoom lens 14, the diaphragm 16, extender lenses 18A and 18B and the master lens 20. The fluctuation amount of a focus associated with the change of at least one of the zooming position of the lens 14, the diaphragm value of the diaphragm 16 and the extender positions of the lenses 18A and 18B is obtained in advance. Then, the position of the lens 20 is controlled to cancel the fluctuation amount of the focus obtained based on the change of at least one of the zooming position of the lens 14, the diaphragm value of the diaphragm 16 and the extender positions of the lenses 18A and 18B. |
