The present invention provides an image capturing apparatus, which comprises a plurality of photoelectric converter-containing pixels that are positioned horizontally and vertically and a gain circuit, has a gain controller that can control the gain of the gain circuit in N stages (where N is an integer equal to or greater than 2). The gain circuit outputs each of a plurality of signals given by the product of the output signal from one of the plurality of pixels and the gain in each stage of the N stages.