Of all my 55mm 1.2 the 223XXX is the least mint but still EXC++, I did not like it because it was dusty, but I knew it could be cleaned and how. Did not want to pay, but I was hesitant to clean it because Nikon uses a lot of adhesive on the screws of these old lenses to keep them together, I end up ruining lenses when I bust the screw heads.
Decided to go for it, judicious use of solvent on q tips did the trick, the lens is now pristine inside. Tested it after reassembly and it performs quite well, not my best 55mm but decent.
Here are the lenses, most of you have seen them multiple times, this 223XXX is the only non-ai, it had the ai ring at some point but I took it for a better lens, the other non-ai is 172XXX which cannot be converted.
Below are test shots, go look at flickr 100% if you care for that, don't have a Z7, so non-ai are tested at 24MP.
Look at the detail and depth of field at different key apertures, 1.2, 2.0, 5.6. At 1.2 it is sharp but 'veiled' at 2.0 and up it is an excellent performer.
at 1.2 there is a lot of detail on the tress that can be seen at 100%, at this magnification it looks washed out but it is not, it is veiling or low contrast. My 195XXX is better, as sharp at 1.2 as at 2.0, but it is new condition and has never been touched by hands other than at Nippon Kogaku factory.
