Objective lens for image pickup apparatus with size of image pickup surface changeable between aspect ratios

摘要

An objective lens for application to an image apparatus of which the size of the image pickup surface is changeable over between a first mode of a first aspect ratio and a second mode of a second aspect ratio has first optical member for extending the focal length of the objective lens, second optical member for shrinking the focal length of the objective lens, an operating member, and a transmitting mechanism for transmitting the operating force of the operating member to the first optical member under the first mode, and transmitting the operating force to the first and second optical member under the second mode, and by the operation of the operating member, under the first mode, the first optical member is removably insertable into the optical path of the objective lens, and under the second mode, the first and second optical member are removably insertable into the optical path of the objective lens.