Patent ID: 7477313

Claim:
An optical apparatus comprising: a light-quantity adjusting apparatus, wherein the light-quantity adjusting apparatus comprising: a main body that includes a fixed opening through which light passes; a drive source; plural light-blocking members that are moved in a region overlapping the fixed opening in an optical axis direction to change an area of a light-passing aperture formed by the plural light-blocking members; a neutral density filter that is movable in another region overlapping the fixed opening in the optical axis direction; and a drive mechanism that drives the plural light-blocking members and the neutral density filter by drive force from the drive source, wherein the drive mechanism includes a first drive member that receives the drive force from the drive source to be operated to drive the plural light-blocking members, and a second drive member that receives drive force from the first drive member to be operated to drive the neutral density filter, and wherein the second drive member does not receive the drive force from the first drive member until the area of the light-passing aperture reaches a predetermined area, and receives the drive force from the first drive member after the area of the light-passing aperture reaches the predetermined area to be operated to drive the neutral density filter at a moving speed higher than that of the plural light-blocking members with respect to the fixed opening.