Image capturing apparatus and control method thereof

An image capturing apparatus comprising:

• an image sensor in which a plurality of pixels including focus detection pixels that output signals so as to be able to acquire a pair of focus detection signals having parallax based on light fluxes that have passed through mutually different pupil regions of an imaging optical system are arranged;
• a movement control unit that moves incident positions of the light fluxes on the image sensor;
• and
• a focus detection unit that performs phase difference focus detection using the pair of focus detection signals,
• wherein the movement control unit periodically moves the incident positions a plurality of cycles during an exposure period for acquiring the pair of focus detection signals, and a point spread function obtained as a result of the movement in a first direction in which the phase difference is detected has three or more peaks, and
• wherein the focus detection unit is implemented by one or more processors, circuitry or a combination thereof.