| 摘要 |
An optical system for use in a focus detecting apparatus has a photographing lens for forming an image of an object, a condenser lens disposed behind, with respect to the photographic lens, a plane corresponding to a photographing film surface, and a pair of split optical elements located behind the condenser lens for splitting the image of the object. The split optical elements are symmetrical with respect to a meridional plane of the condenser lenses. Using a line sensor, a relative positional shift of the images is detected by the optical system to determine a focal position. The optical system has a sufficiently large spherical aberration that the diameter of the minimum circle of confusion at the maximum contrast position is larger than the width of one bit of the line sensor. |
