Image sensing apparatus, image sensing system and focus detection method

摘要

An image sensing apparatus including: an image sensor (107) including a plurality of focus detection pixel pairs (SHA, SHB, SVC and SVD) that perform photoelectric conversion on each pair of light beams that have passed through different regions of a photographing lens (100) and output an image signal pair; a flash memory (133) that stores shift information (177) on relative shift between an optical axis of the photographing lens (100) and a central axis of the focus detection pixel pairs (SHA, SHB, SVC and SVD); a correction unit (170) that corrects a signal level of the image signal pair based on the shift information and (177) exit pupil information (176) of the photographing lens (100) so as to compensate for an unbalanced amount of light that enters each of the focus detection pixel pairs (SHA,SHB, SVC and SVD); and a focus detection unit (901) that detects a focus of the photographing lens (100) using the image signal pair corrected by the correction unit (170).