On Sat, 25 Apr 1998 00:02:09 GMT, Paul Telmosse wrote:

>It seems that the majority of photographers agree that a lens
>performs at its best when stopped down by 2-3 f/stops from its
>maximum aperture.

No!!! Most good lenses for 35mm perform best in the center around
f5.6-8 regardless of maximum aperture (and best in the corners
around f8-16, depending on lens type - and good larger-format
lenses generally peak at even smaller stops). It is time the old rule-o'-thumb died, 'cause it is wrong!

>Shouldn't a well designed/manufactured lens be at its best at all
>apertures (ignoring diffraction effects)?

No - that is not possible, alas, though there are some lenses
that for practical purposes are very good at all stops to f16.

> Does anyone know lenses that are good at all apertures (specially
>Nikons)?

Hmmm, well, you may want to look at my Nikkor evaluation list
on my web page, under "I babble" (I try to indicate those lenses
that are good wide open - and these are about equal to each other
[and very good] at stops down to f16). Nikkors that come to mind
that are good wide open: 16mm f3.5, 28mm f3.5PC, 28mm f2.8 *AIS*,
28mm f3.5 *AI/AIS*, 35mm f2 AI/AIS, 35mm f2.8PC, 50mm f1.2 around 10',
50mm f1.8, 55mm f2.8, all the Nikkor 85's, 105mm f2.8M's, 105mm f2.8E,
105mm f2.5 (not close up), about all the 135's, all the 180's, 300mm
f4 and f2.8, etc...; and a few zooms: the (rare good sample of) the
MF 35-105, the 75-150E, the 70-210E, the 80-200mm f4, and the
80-200mm f2.8's. (Not a very short list...;-) There are many other
Nikkors that are quite useable wide open, if not up to the above...
(the 18mm f3.5 [in color], 35mm f1.4 [especially at mid-distances],
the 200mm f4's, 300mm f4.5's, etc...; and some zooms: 35-70mm f2.8,
50-135mm, 75-300mm, and 100-300mm - I have probably forgotten some...).