| 摘要 |
PURPOSE:To obtain a focus detecting method which can easily calculate the direction and quantity of defocusing fast for a subject which has a periodic light intensity distribution by dividing the luminous flux from a body into lights passing through plural areas and performing contrast arithmetic. CONSTITUTION:The luminous flux from the body is divided into the lights passing through the different areas 5a-5e on the pupil of a photography optical system, and the divided pieces of luminous flux are photodetected by optical electrode converting means 7a-7e having plural photodetecting elements and then photoelectrically converted. At least two signals are selected among plural photoelectrically converted output signals and added at their optional positions. Further, they are added at positions different from the optional positions and contrasts are calculated respectively. A focusing position is evaluated from those two calculated contrast values. Consequently, a focus detection error for the subject having the periodic light intensity distribution is reduced and the direction and quantity of defocusing can easily be calculated. |
