Hello Community,

I am trying to optimize a lens that comes after the STOP. When I try to optimize the lens for maximum performance and minimum distortion the STOP gets vignetted as the diameter of the lens is fixed. The clear semi diameter of this lens is fixed and already at its maximum and cannot be increased. The vignetting for the rays from the maximum field is in such a way that the rays from the top half of the STOP are completely avoided and the rays from the bottom half of STOP is only considered. How can this be controlled. Which operand can be used to make sure that at least some of the rays from the top half of the STOP are always used.  I cannot use the option “clear set vignetting” and set new vignetting factors as the initial vignetting values of the STOP cannot be changed. Please see the pictures attached below. Only the rays from the maximum field are shown in the layout.