| 摘要 |
The colour modulation optical filter comprises polarizer elements and birefringent elements parallel to/each other and perpendicular to the filter axis. It comprises at least two birefringent elements (B1, B2) arranged adjacent to each other, the ordinary optical axes (O1, O2) of these two birefringent elements being arranged at 45 DEG with respect to each other. Said two birefringent elements are arranged between a first polarizer element (P1) and a second polarizer element (P2), means being provided to rotate at least the polarization axis of the second polarizer about the filter axis, the operating delays ( DELTA 1) and ( DELTA 2) between the propagation times of the polarized light waves along the ordinary optical axis and the extraordinary axis of the birefringent elements (B1, B2) being selected so that when the polarization axis of the polarizer (P2) is rotated by 180 DEG about the filter axis, a closed curve is drawn on the chrominance diagram, the curve being situated in the area corresponding to the fundamental colours and outside the central area of the diagram corresponding to the white. Utilization particularly in shot-taking, analysis and creation of images and lighting. |
