I have only had my Fujinon 65mm f5.6 SWD for a short time but the test frames I have taken seem high-contrast and sharp at F/22. I have the Schneider IIIc centre filter for it and the comination produces evenly illuminated images. Wista metal field uses a fresnel lens optimised for lenses 135mm and longer so the illumination on the GG still has strong fall-off towards the edges.