Patent ID: 8576329

Claim:
A focus detection apparatus for setting a focus detection area corresponding to a selected focus state detecting position, and detecting a defocus amount in the focus detection area on the basis of a phase difference between two images corresponding to the focus detection area, the focus detection apparatus comprising: an image sensor comprising a plurality of pixels for focus detection configured to receive a pair of respective light beams transmitted through different pupil areas of a photographing lens, wherein a pair of image signals are output from the plurality of pixels for focus detection; a determination unit configured to determine a tilt of the focus detection area, depending on positional information on the focus state detecting position with respect to an angle of image sensing view and exit window information on the photographing lens; and a detection unit configured to detect the defocus amount on the basis of a phase difference between a pair of images obtained from pixels for focus detection corresponding to the detection area with a tilt determined by the determination unit, from among the plurality of pixels for focus detection.