Quote Originally Posted by E. von Hoegh View Post
I'm aware of this; all I can say is my example performs very satisfactorily at infinity. I think the optical design is slightly different from the earlier versions, five in four instead of five in three like the previous versions.
I was happy with mine too. That MP and PP found all of the 55/3.5 MicroNikkors they tested unacceptable at some apertures at infinity speaks to differences between formal and informal lens tests. Remember, they published no test reports on any version of the 55/3.5 MicroNikkor.

Your comment re changed layout surprised me. Since my memory may be failing I visited the mir site to see what it says about 55/3.5 MicroNikkor designs. There may well have been redesigns, but all versions were five element in four group double Gauss types.

You may have been led astray by this text (see for yourself at http://www.mir.com.my/rb/photography...5mmmicro.htm):

(Compared to 5 elements in 4 groups used in last versions of Ai-Spec f/3.5 Micro-Nikkor which again different from early versions of f/3.5 lens that has a simpler 5 elements in 3 groups design)
which is not consistent with cross-sections and text descriptions of older 55/3.5s on the site.

It is also not consistent with the cross-section shown in the instruction manual for the 55/3.5 MicroNikkor-P I bought in September, 1970. I just dug it out, it is in front of me now.

Many of the facts asserted on the Internet just aren't so, alas.