1. A camera system, comprising: an imaging optical system configured to form an optical image of a subject; an imaging component configured to convert the optical image into an image signal and successively acquiring images of the subject based on a photography condition; a display component having first and second display regions that allow a plurality of the images acquired by the imaging component to be displayed side by side; a condition adjustment component configured to adjust the photography condition to a first photography condition in a first period; and a display control component configured to control the display component to display at least part of a first image acquired by the imaging component under the first photography condition as a reference image in the first display region and to display at least part of a second image acquired by the imaging component at a different timing from that of the first image as a comparative image in the second display region.