This was my first experience with the W Rokkor SG 28mm f3.5. I tested it on a EOS M3 body with a Fotasy adapter. It has an all metal body. Like many f3.5's it jumps from f3.5 to f5.6. It does offer 1/2 stop clicks from f5.6 up. Focusing was not difficult but not nearly as effortless as with a Zuiko lens. Focus dampening is smooth and light. Sharpness is acceptable at f3.5 in most situations. At f5.6 it tightens up a little bit. Contrast is good except for backlit situations. Flare causes a framewide reduction in contrast. Corners are reasonably sharp. Vignetting is noticeable at f3.5. Color rendition is typical Minolta. It's a tad flat but accurate. Black and white rendition is excellent. See the example below. Red on red is difficult for lenses to render in b/w. This lens handled it with ease. This lens will fringe in harsh lighting at f3.5. It will be noticeable but easily correctable.