Imaging apparatus, imaging system, imaging apparatus driving method, and imaging system driving method

An imaging apparatus comprising:

• a plurality of pixels arrayed in a matrix shape, each including a plurality of photoelectric conversion units configured to generate signal charge, and to output a signal based on the signal charge;
• wherein at least each of a part of the pixels of the plurality of pixels outputs a first signal based on m (m is an integer) photoelectric conversion units which each of the pixels includes, the signal charge of n (n is an integer less than m) photoelectric conversion units within one frame period;
• and wherein each of the plurality of pixels outputs a second signal based on the signal charge of the m photoelectric conversion units which each of the plurality of pixels includes, within the one frame period;
• and wherein the number of signals based on the first signals which the imaging apparatus outputs is less than the number of signals based on the second signals which the imaging apparatus outputs.