On Tue, 29 Oct 2002 13:33:16 -0800 (PST), bigrocketman3@webtv.net (Steve McDonald) wrote:

> I said that UV/Haze filters can give a slight optical advantage in
>some circumstances. I can see these small improvements in longshots
>through light smoke and fog, even if you can't. At 10,000 feet altitude
>on sunny Summer days a UV filter has reduced some color artifacts for
>me. That's not too radical a claim to accept, is it?
>
>Steve McDonald

Sorry, but yes, it is... If the lens will pass
very little UV, and the CCD is pretty much insensitive
to UV, the result is that a UV-blocking filter will
have about as much effect as clear glass (or nothing,
assuming the lens has several glass elements and the
CCD type is not unusually sensitive to UV...). Even
with film (which is FAR more sensitive to UV than CCDs),
I have never been able to establish that there is ANY
visible difference with/without a good UV filter even
with long lenses, shooting over water or through
atmospheric "glop" at distances of a few miles... If
you have WB locked down, some UV filters have a very
slight yellow color, and this *may* account for a
difference (but it would be very subtle...). If
you do side-by-side tests with/without the UV, and
show some undoctored frame-grabs on a web site, I
will look at them - but I have never been able to
detect any difference...