Focusing method for zoom lens

摘要

In the disclosed zoom lens three or more zoom components are located on the image side of a stationary component which is stationary during both focusing and zooming. The three or more zoom components are moved during zooming and are provided into a front portion which is moved for focusing, and a rear portion which remains stationary during focusing. The front focusing portion includes at least two components which move together when focusing, but when zooming move relative to each other so as to change the focal length or power of the front portion. This has the advantageous effect of reducing the difference between the amount the front portion needs to move for focusing at the wide angle position and at telephoto position.