Influence of the position of the stop in a lens system

Stop in a lens system is important because it directly determines the light interaction with the edge of the aperture of the lens surface, which exsited physically in the manufactured lens system. Therefore, different positions of the stop might have an influence on the Point Spread Function (PSF). VirtualLab Fusion provides an ease way to investigate this influence by considering the diffraction, if necessary, from the edge of each surface, especially with inclined illumination.