In article <41vgd1$e9i@news.fsu.edu>, prosper@xi.cs.fsu.edu says...

>Well, for one thing, macros are very highly corrected optics which
>almost always provides good to excellent performance throughout the
>ENTIRE aperture range, although standard lenses are no slouches in
>this department either. Perhaps more importantly, macros focus much
>more closely than standards AND generally include one or two extra
>stops at the low end of the aperture scale. You will not always
>need this added flexibility, but it IS there if you do.

You may want to check-out "SUBJECTIVE Lens Evaluations (Mostly
Nikkors)" above - the 60mm Nikkor macro is not very good at infinity
at apertures much wider than f8 (!), though it is really excellent at
infinity at f11. And the rules of diffraction make f16 and smaller the
great leveler among lenses, with most lenses for 35mm performing
well at f16, but on the edge of good quality at f22, and over the
edge by f32 - in other words, f22 and f32 may seem useful for
DOF increase, but the resulting images may not be sharp enough
for the critically inclined.....
Hope this helps.