| 摘要 |
PURPOSE:To attain off-axis focusing and also bring plural subjects into focus by putting the target subject at the shortest distance in focus during normal photography, and calculating the depth of focus according to the purpose and setting the optimum distance of a photographic lens. CONSTITUTION:Line sensors RL and RR start scanning synchronously with each other with a power switch ON. At the same time, the photographic lens 11 is extended and stops at the shortest distance. When a normal photograph is taken, a spot light projection tube 1 is rotated and an infrared-ray RED2 emits pulse light to make a scan once. At this time, the distance of each subject is calculated by using reflected light from the surface of the subject and the result is stored in a memory 14 successively. Then, the shortest distance is found and the lens 11 is set to the shortest distance. When subjects are shot by a movie camera, the projection tube 1 is scanned continuously and the best distance for bringing the subjects into focus is calculated on the basis of respective subject distances, stop information, and the focus length of the lens 11, thereby performing focusing operation intermittently and continuously. |
