Patent ID: 7903154

Claim:
An optical apparatus comprising: an image pickup unit including an image pickup element, the image pickup unit configured to obtain a photoelectrically converted output corresponding to an object image formed on a surface of the image pickup element; an exposure time control unit configured to control an exposure time of the image pickup element; a sensitivity adjustment function unit configured to set an ISO speed rating value of the image pickup element, the ISO speed rating value corresponding to an amplification factor of the photoelectrically converted output; a lens unit including a plurality of elements to be electrically driven and configured to form the object image on the surface of the image pickup element; and a control changing unit configured to control the plurality of electrical elements of the lens unit, wherein when the image pickup unit is performing photoelectrical conversion or is processing photoelectrically converted data, a method of controlling at least one of the elements of the lens unit is changed so as to reduce power consumption according to the ISO speed rating value set by the sensitivity adjustment function unit.