To display a stable low pass effect and the obtain a satisfactory picture by forming a prescribed continuous shape and refractive index distribution in a radial direction by setting up the enter of an incident luminous flux as an origin and generating a prescribed wave front aberration on the luminous flux.

A zoom lens consists of a 1st group having positive reflective power, a 2nd group having negative refractive power, a 3rd group having positive refractive power, and a 4th group having positive refractive power, executes power variable operation by moving the 2nd group and executes the compensation and focusing of an image face by the 4th group. An optical low pas filter(LPF) is added to the 14th surface of the 3rd group lens close to an iris as a shape asymmetrical with a specific radius ofd curvature. When a coordinate system on the lens surface is chosen to be the cylindrical coordinate system (ρ, ) consisting of the radial direction coordinate ρwith the center of the aperture as the origin and a operational direction coordinate , the shape S(ρ, ) of the optical LPF is expressed by the equation given. In the equation Rm(ρ) expresses the shape in the radial direction, (m) is an integer and Am and δm are constants.