Image sensing apparatus

A method of controlling an image sensing apparatus having an image sensing means including an image sensor having a plurality of image sensing pixels for photoelectrically converting an object image formed via an imaging lens to generate an image signal, and a plurality of focus detection pixels discretely arranged between the plurality of image sensing pixels, the method comprising:

• a shift detection step of detecting a shift amount between images obtained by a plurality of image sensing operations using signals of the image sensing pixels contained in image signals obtained by the plurality of image sensing operations that are continuously obtained by the image sensing means and shifted in position from each other;
• a combining step of combining signals of the focus detection pixels contained in the images obtained by the plurality of image sensing operations on the basis of the shift amount detected in the shift detection step;
• and
• a focus adjustment step of adjusting a focus of the imaging lens by using signals of the focus detection pixels before being combined in the combining step, and signals of the focus detection pixels that are combined in the combining step.