Patent ID: 6927798

Claim:
A light amount adjusting apparatus comprising: a driving source; a plurality of light shielding members each having a notched portion, said plurality of light shielding members being adapted to form a light passing port, in which a light shielding member of said plurality of light shielding members is moved by being driven by said driving source to thereby vary an area of said light passing port which is formed by said notched portions of said plurality of light shielding members; and a filter provided for said notched portion of a light shielding member of said plurality of light shielding members, in which said filter is provided so as to cover a part of said notched portion and has a first area having first light transmittance and a second area having second light transmittance lower than said first light transmittance in order from a center of said light passing port toward a periphery thereof, wherein in a state where the whole light passing port which is formed by said light shielding members is covered with said filter, when the area of said light passing port is in a maximum state, a relation A 5 <A 4 is satisfied assuming that, in said light passing port, an area of a portion covered with said first area of said filter is set to A 4 , and an area of a portion covered with said second area of said filter is set to A 5 , wherein said areas A 5 and A 4 satisfy a relation 4 ×A 5 < A 4 .