| 摘要 |
A light amount adjuster includes two filter members (ND1, ND2), each having a gradation ND region where the transmittance continuously changes, disposed such that the two filter members (ND1, ND2) face each other and the direction in which the gradation of one of the filter members changes differs from the direction in which the gradation of the other one of the filter members (ND1, ND2) changes and configured such that the filter members (ND1, ND2) can move in a symmetrical manner with respect to each other. |
