Patent ID: 6924941

Claim:
An optical apparatus comprising: an optical system provided with a variator lens movable along an optical axis and a focus lens movable along the optical axis, said variator lens varying a magnification of the optical system and said focus lens correcting a focus change due to the movement of said variator lens; an image taking device for taking an image supplied from the optical system; a zoom actuator for driving the variator lens; a focus actuator for driving the focus lens; a zoom position detecting device for detecting the position of the variator lens; a focus position detecting device for detecting the position of the focus lens; an aperture stop member having a plurality of movable vanes, said plurality of movable vanes changing a diameter of an opening of said aperture stop member to change a luminous energy passing through the optical system; a filter member integrally set to at least one of the movable vanes, for changing the luminous energy passing through the opening; an aperture stop state detecting device for detecting the opening state of the aperture stop member; a memory for storing information on the relation between the position of the variator lens and the position of the focus lens for keeping a focused state at the zooming; and a control device for correcting said information in accordance with an output of the aperture stop state detecting device and controlling driving of the focus lens by using said corrected information.