1. An imaging device comprising: an aberration control optical system comprising a lens and an aberration control unit for causing aberration; and an imaging element operable for imaging a subject image passed through the aberration control optical system, wherein a first angle formed by an optical axis and a light beam passed through the aberration control optical system is smaller than a second angle formed by the optical axis and a light beam from an outermost peripheral part of the lens defining an image side numerical aperture of the aberration control optical system without the aberration control unit, wherein 1/(2*sin Um)>1/(2*sin K) is satisfied and where Um is a maximum of angles formed by the light beam, and K is an angle formed by a limit incident light beam at which the imaging element tolerates an influence of shading and the optical axis.