My copy of this lens was made by Tokina. I used a Minolta TX mount to test this lens on my Eos M3. This lens surprised me. I expected it to be sharp at f8 w/ lots of Chroma. I was wrong. This old lens is sharp enough at f2.8 and it is sharp up to f11. The whole frame tightens up nicely as you climb through the f-stops. Fringing is barely noticeable at 100% crop. I did not test flare yet. Colors are a natural. Contrast is consistent thru the entire aperture range. Bokeh is a tad rough above f2.8. At f4 and up highlights form hexagons and circles. The focus throw on this lens is very long. It's a long tedious turn from 3 ft to infinity. It is difficult to focus handheld. Even on the Eos M3 with the image magnified I was unsure of focus. Focus is heavily dampened, but it might need a lube.