Patent ID: 8269861

Claim:
An image acquisition apparatus comprising: an optical imaging system; an image sensor configured to acquire an image of an object through the optical imaging system and to produce an image signal; a plurality of pupil-division lenses configured to pupil-divide a light flux of object image light passed through the optical imaging system in an area on a surface of the image sensor; a coordinate recording unit configured to record coordinate information to specify the area on the surface of the image sensor; a correction unit configured to execute, based on an optical characteristic of the plurality of pupil-division lenses corresponding to the area and characteristics of the image sensor, a correction process to correct the image signal obtained by an image acquisition operation of the image sensor, according to the coordinate information recorded in the coordinate recording unit; and a focus detection unit configured to detect a focal point based on a selected one of the image signal before the correction process and the image signal after the correction process executed by the correction unit.