The images of a straight edge in coherent illumination produced by an optical system with circular aperture and apodized with multiple filters have been studied. The most common problem encountered in the coherent-imaging techniques is the edge-ringing. To minimize the edge-ringing, multishaded aperture method has been proposed. Image intensity distribution curves are drawn and edge-ringing values are evaluated. The results are compared to that of the airy case with the use of single, double and triple filtering.

The images of a straight edge in coherent illumination, produced by an optical system with circular aperture and apodised with amplitude filters have been studied. The image quality assessment parameters such as edge-ringing, edgegradient and edge-shift of the edge fringes have been studied as a function of apodisation parameter for various degrees of defocus, Coma and primary spherical aberrations. It is found that, at certain combinations of aberrations the quality of the image of straight edge objects can be improved.