In an imaging apparatus adding image signals output from a sensor array which receives a light flux through an optical system and performs photoelectric conversion thereon, the sensor array being arranged a plurality of light receiving elements two-dimensionally, the imaging apparatus includes a pixel adding unit that divides the light receiving elements on the sensor array into a plurality of groups with a region including predetermined types of pixels as a group unit, and that adds, for each of the types of pixels, image signals output from the pixels included in four of the groups which are positioned “n” groups away from each other on the sensor array.