Exactly, corners are bearable at f/4 and fully acceptable from f/5.6. The other real issue with this lens is, apart from the wavy distortion, the sensitivity to flare (unlike the 20/3.5 AI). Otherwise it is a joy to use because of its ideal size. Manual focussing (on a matte screen) is difficult in dark places, but with the Z cameras that's no longer an issue.
Right... At the price of just $85, I'll forgive her for all her shortcoming
The lens initially had dirt and oil inside, but after being rebuilt, it looks like it hasn’t seen much use at all.
