In article <853502231.24732@dejanews.com>, dr.lee.brown@internetmci.com says...

>I am evaluating a Nikon F2.8 80-200mm lenses with a B&W UV filter. I am
>getting mixed results. I have an old Kiron F4.5 80-200 without filter
>that has provided consistent sharp, grainless, and accurately colored
>photographs. That has not been my experience with this particular Nikkor.
>I have also gotten excellent results with my Nikkor F3.3-4.5 35-70mm lens. I
>have never used filters in the past, but I am horrified to even think of
>using the F2.8 without a UV filter. I am at a loss as to what is causing
>the increase grain and lack of sharp focus with the F2.8. Also, the color
>rendition is not as pure. Could it be that using autofocus with the F2.8
>is not as reliable as using the manual focus with the Kiron (an manual
>focus lens)? Could it be that the B&W UV filter is causing some
>distortion? Should I get the Nikkor UV filter instead of the B&W Proline?
>Should I simply return this lens and get a replacement? Are there better
>F2.8 80-200 lenses? My camera body is a Nikon 6006. I am not new at
>photography, but I am not familiar with the new technology. [...]

Hmmm, grain is not a lens effect, except that VERY softly focused areas
will appear grainier.... I would suggest removing the filter for a while,
and seeing if that helps. If it does not, see if exchanging the lens does
(even the best [and the Nikkor 80-200mm f2.8 is one of the VERY best]
lenses come in an occasional bad sample...). I personally do not like
auto-focus, but it is not generally so inaccurate as to cause the problems
you appear to be having. I assume that you are using adequately high
shutter speeds (and/or good tripod technique)? The big zoom can be hard to
hold steady for long periods, but I find that for short periods, the mass
and length help me make sharp pictures hand-held at slower speeds than would
be possible with smaller/lighter lenses. BTW, if most of your photos with
this lens are taken near 200mm, near minimum focus, near maximum aperture,
you have found the conditions under which this outstanding lens is not
great...
Hope This Helps