(X post with vivitar lens club).
A desultory low bid, put in more for amusement than anything else, confounded me by winning the lens. Since the lens in question is the desirable vivitar series 1 fast 28mm f1.9, tokina made, obviously I'm happy. The seller had noted that the lens has fungus, but I'm hopeful that shouldn't be too difficult too deal with, primes aren't so complicated - it's not bad anyway, probably having a slight effect mainly at f1.9.
Distinctly soft and glowy at f1.9, IQ is good, particularly centre, at f2.8 on. But I was slightly disappointed at signs of decentering - images softer at right.
Click on this composite to see comparison crops f1.9 - f2.8 - f4 - f5.6 (samsung NX20, 5472x3440px, 3MPx)
Sample pics from around Conwy, mostly f4, f5.6.
1:1 pixel peep crop from above: