An imaging system is provided and includes an imaging lens and an imaging device such that the maximum diameter of an effective region of a point image becomes a size covering three or more pixels of light receiving pixels, the point image being projected onto a light receiving surface through the imaging lens from any position of X, Y, and Z directions. A signal processing unit in the imaging system executes restoration processing on first image data output from the imaging device that images an optical image of a subject projected onto the light receiving surface through the imaging lens, the restoration processing being executed to generate second image data equivalent to the first image data output from the imaging device when the resolving power of the imaging lens is higher.