Just bought a red ring version for about 230$ used.At first, I was pissed off, as photos seemed to be very soft. Then I realized focus scale is not correct, and i should not go beyond 2m marking for infinity focus.After I learned correct focus distances, all my test photos were tack sharp from...
Very sharp at f4; good build quality; extremely wide on a ff
Inaccurate focus scale; extreme lower right corner is slightly soft