On Wed, 30 Oct 2002 01:23:34 -0800 (PST), bigrocketman3@webtv.net (Steve McDonald) wrote:

> Sceptics about the optical effects and value of using Ultra-Violet/
>Haze filters might check out this website presented by Nikon. The first
>link is a direct one to the section about UV/Haze filters. There are a
>number of sample pictures made without filters and then some made with
>many of the popular brands. Note that there is an unequivocal reference
>to the effect UV light has on both film and CCD photography. As I have
>seen in my own video recordings, there is a portion of the UV light
>spectrum that is above the frequency we can see directly, but is
>detected by CCDs and which alters video images. The aspects of haze
>reduction by these filters is also discussed.
>
> This Nikon website, that is featured by MTU on their pages, also
>contains good information about many other subjects related to film and
>video photography.
>
>http://www.cs.mtu.edu/~shene/DigiCam/User-Guide/filter/filter-UV.html
>
>http://www.cs.mtu.edu/~shene/DigiCam/User-Guide/950/index.html
>
>Steve McDonald

Well, from the first site you gave, I had trouble detecting
any material differences at all in the first UV/no-UV images
(viewing the enlarged images on two different monitors, with
the different-colored edges removed) other than exposure
in this first pair and a slight blue predominance in the "with
UV filter" example (which is odd, since the UV filter is
purported to reduce excess blue from UV-sensitive film - and
these examples were from film images, with film being more
sensitive to UV effects than CCDs...). In the set of images
with no-filter, followed by examples with six brands of UV
filters, the images again show that there really are no
significant differences. With the various skylight filter
brands, there are slight color casts, as expected - these
all have color, and it varies in strength and color among
the various brands. BTW, the verbal descriptions of the
effects of the UV filters are not supported by the images
themselves - though some UV filters do have a slight yellow
color, affecting the results VERY slightly... Your second
example merely refers back to the first, which does not add
support. I think the Nikon page simply supports what I have
been saying with the examples, if not with the erroneous
text - and, one must always question the mythologies that
are present in photography (though there numbers are tiny
compared with those that abound in audio...;-). Again,
with multi-element glass lenses, very little additional UV
that could be imaged will be absorbed using a UV filter,
and unless the color in the filter is significant, and
unless the WB is locked, there will be no significant
effect on the image when a UV filter is added - and this
is especially true for video since CCDs are less sensitive
to UV than is film... If you can present honest side-by-side
comparisons that can show a significant difference from
adding a *colorless* UV filter in video, I'm interested in
seeing them - but this site fails to do this... (I may
do this myself, to show that there is no significant
advantage to using UV filters except for lens protection).