In article <4suo7k$e4j@crl11.crl.com>, ra@crl.com says...
>Bob Neuman (d_ruether@hotmail.com) wrote:

>: >If the lens is to be used for general work, some near infinity, the 55mm
>: >f3.5 can have enough field curvature to be a problem with distant subjects
>: >at wider apertures - the 55mm f2.8 version does not have this problem.
>:
>: While the above is true, I just tried another 55mm f3.5 which showed
>: virtually no field curvature wide-open at infinity, and which is VERY sharp
>: over the whole frame wide-open. Lens samples can vary (and some lenses show
>: more sample variation than others).

> Shouldn't be a problem with 55 micro 3.5 or 2.8. Both are flat-field
>(true macro) lenses. These are great lenses for copy work because of extreme
>sharpness from edge to edge.

Umm..., I have seen some samples of the 55mm f3.5 that were not flat-field,
which is what prompted my original post (odd, too, since most Nikkors of all
types are flat-field, and the 55mm f3.5 was designed as a macro.....).
Hope This Helps