In this research we studied the effect of Gaussian filter on point spread function(PSF) for an optical system consisted of circular aperture with non-central circular obscuration with Gaussian Illumination. The study was in case present different types of first and third order aberrations. and searched to get better combination of them to made optimum balance of third order aberration... https://www.ealisboa.com/flash-choice-Sten-Jacket-M-flash-find/