In article <4sg8m7$vq@newsstand.cit.cornell.edu>, d_ruether@hotmail.com says...
>In article <31EA8E2B.72EE@ucla.edu>, birdy@ucla.edu says...
>>There are many very fine 55 mm F2.8 and F3.5's available on the
>>used market. the 55 mm F2.8 is a very fine lens; the only disadvantage
>>is needing the extension tube to get to 1:1. The new autofocus Nikkors
>>all go to 1:1 without tubes. If you need a bargin, look for an AI'd
>>F3.5. I've seen good ones at camera shows go for about $100.

>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.
>Hope This Helps

(Nothing like amending your own post after acquiring recent information! ;-)
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).
Hope This Helps