1. An image-capturing apparatus comprising: a single optical system; split means for splitting light originating from the single optical system into a plurality of lights a plurality of image-capturing elements which receive the plurality of lights and have the same number of pixels and different pixel sizes; and drive means for driving the plurality of image-capturing elements; angle-of-view change operation means; display means; control means for outputting, in a switching manner, image signals output from the plurality of image-capturing elements to the display means in response to operation of the angle-of-view change operation means; wherein the plurality of image-capturing elements are formed from a first image-capturing element and a second image-capturing element which is smaller in pixel size than the first image-capturing element; and the control means subjects at least the first image-capturing element to electronic zoom control.