Image processing apparatus

An image processing apparatus comprising:

• an image pickup device having a plurality of pixels arranged along an image pickup plane, the pixel having a micro lens for condensing light from outside into the pixel and a photoelectric conversion region provided beneath the micro lens and for generating a photoelectric conversion signal,
• the photoelectric conversion region including an upper electrode and a lower electrode sandwiching a photoelectric conversion film, the upper electrode or the lower electrode being divided into a plurality of portions, and forming at least a first region, a second region, and a third region that are divided and arranged in a plane parallel to the image pickup plane by the divided upper electrodes or the lower electrodes, the first region having a shape for forming a circle, the second region and the third region being arranged outside the first region;
• a readout unit configured to read out photoelectric conversion signals obtained by one image pickup operation to serve as respectively first, second, and third signals from the first, second, and third regions;
• an image signal processing unit configured to have a first mode that forms a first image signal by adding the first, second, and third signals from among the first, second, and third signals that have been read out by the readout unit, and a second mode that forms a second image signal by using the first signal instead of using the second and third signals;
• and
• a focus detection unit configured to generate a focus detection signal by using at least the second and third signals.