I have a 35/2 Nikkor O that I am very happy with, I don't think you'll be dissapointed with that lens.
thanks E. Another thing I noticed is that the distance scale markings on the AIS 28/2 were much harder to use than on my 28/3.5 (which is a pre-AI K series). I assume this is due to a change in focusing throw? Do all AIS lenses have shorter throw (and therefore less useful lens barrel markings)?
E., the 28mm 3.5 was recalculated when it went to Ai-s.
Something seems wrong, both my 28mm f/2 don't look like this wide open. It does have front CRC like the 28mm f/2.8 Ai-s (which is an excellent refinement of the f/2 design BTW) and wide open you will see a bit of field curvature so make very sure what you have in focus is what you want, its not Flat Field and the later 3.5 is much better in this regards (and I think you're seeing some of this). Try the test again with more focus bracketing with f/2 you really have to nail the focus even if its a broad/landscape type shot. IMO the f/2 lens strength is mid to close distances (1-2.5 meters) when its wide open or close to it in low light.
thanks RidingWaves - I am pretty positive something was drastically wrong with the lens or else it would not have such a stellar reputation. FWIW I did extensive testing with all different focus distances and apertures and the thing was awful wide open and only rivalled the 3.5 after F8, as I said. In any case I am glad I returned it!
The front CRC is not too complex but its very much possible that it was cleaned and reassembled incorrectly. If you really don't need the extra stop the f/2.8 Ai-s is truly stellar, and I'll never not use my old Non-Ai 28mm f/3.5, it just has 'a look'. I like 28's!!