Hi, I am designing a system for collimating a source. My design still greatly suffers from distortion despite having selecting maximum distortion in optimization wizard for developing merit function. I have also tried using operands for distortion but it does not really help and rather increases the aberrations. i also want that after collimation of field points they should overlap at image plane and their sizes should be same for exact over

i have attatched image simulation image for center field point(0,0), seidel diagram and 3-d layout. 

lap at image lane.