Image capturing apparatus and control method therefor

A control method of controlling an image capturing apparatus provided with an image sensor in which at least part of pixels arranged in two dimensions are comprised of a plurality of pairs of first detection pixels and second detection pixels, the first detection pixels and the second detection pixels respectively receiving light fluxes that have passed through different pupil regions of a photographing optical system, the control method comprising:

• a read-out step of reading out, from a memory, position information for the first and second detection pixels and pixel information for distinguishing between the first detection pixels and the second detection pixels stored in a memory;
• and
• a correction step of identifying positions of the detection pixels in the image sensor based on the position information for the detection pixels and correcting, based on the pixel information, a defective first detection pixel signal using defect-free first detection pixel signals and a defective second detection pixel signal using defect-free second detection pixel signals.