Hi--

>I am fishing for commentary on Nikon's 105/4 micro lens. I notice on your
>site that you found it to be lacking in performance with respect to the
>105mm f/2.8 micros. Can you quantify the deficiencies you found with this
>lens? Most commentary from other sources puts the performance of the 105/4
>above that of the 105/2.8. Also, from viewing some of John Shaw's macro
>work, this lens does not appear to be lacking in sharpness across the entire
>frame.
>
>My concerns are with macro performance, as well as use for a general short
>telephoto.
>
>Any commentary you have the time to provide would be most useful to me.

I am mystified by this lens. It is a simple 5-element Sonnar-type,
as I recall, similar to the 55mm f3.5 design. Since it needs to
cover a narrower angle than the 55, its field curvature should be
less evident and it should be a fine lens - BUT, the few I tried
(in short-mount and "micro" versions) were unexpectedly poor,
especially given the positive reviews I've seen elsewhere (I
would not judge by reproductions or VF images, BTW, which can
cover a lot of ills...). The lens was just not very sharp. At
infinity the MF f2.8 is really sharp to the corners wide open - the
f4 wasn't very crisp anywhere in the frame until well stopped down.
In macro I did not do much comparing, but the MF f2.8 is excellent by
two stops down at minimum focus - good enough for me, since I tend to
use small stops anyway in macro work. What little I tried with the
f4 in macro did not impress me. The 55mm f3.5's do vary, and maybe I
hit a few poor 105mm f4's in a row... BTW, the AF 105 is very good
in macro and goes to 1:1 (the MF, with its "floating element" design,
has more problems between 1:1 and 1:2 on a tube [though not when on
a 2X converter]), but it is too fast-focusing near infinity, and
tends to show alignment problems there too. My favorite is the
compact, sharp, fairly-fast, nice-feeling MF f2.8 for both macro
and general use... (Also, BTW, I think John Shaw is an excellent
photographer and writer, but he sometimes recommends gear and
combinations that I don't find quite up to ideal...)