| 摘要 |
<p>A photographic objective (for cinematography, television or still-photography), which is capable of imaging sharply at the same time at least two objects at different distances. This is achieved by placing in front of an objective (1), in its front focal plane (2), a corrective element (3), which is divided into at least two fields, in which the refractive power differs between them. For shading considerations, it is advisable to have the entrance pupil of the objective (1) coincide with the front focal plane (2). </p> |
