IMAGING DEVICE, CONTROL METHOD OF THE SAME AND CONTROL PROGRAM

PROBLEM TO BE SOLVED: To allow a phase difference detection to accurately perform a focus detection irrespective of degradation of image quality due to an optical system.SOLUTION: An image pickup element 103 has a pixel part including a plurality of photoelectric conversion parts receiving light respectively passing through an area of dividing an exit pupil of an optical system 101 arrayed in a two-dimensional matrix, and an optical degradation estimation part 114 estimates a location of a degradation area and a direction of the location in an image on the basis of optical aberrations corresponding to a drive status of the optical system. A focus detection area setting part 106 sets a focus detection area in the image in accordance with the location of the degradation area and the direction thereof, and a focus detection pixel integration part 107 and a correlation computation part 108 calculate phase difference information indicative of a phase difference in accordance with a pair of phase difference detection signals obtained by integrating a pixel signal in the pixel part in the focus detection area, and an AF control part 109 moves the optical system along an optical axis on the basis of the phase difference information, and controls the optical system to a focus position.