Reader's Comments - Index of - Free

Filters - UV or not UV?
them if they can supply what you need!
©Copyright 2003 Bob Atkins All Rights Reserved
Reader's Comments
Personally, the only graph I really find useful is the first one - the frequency response graph. I find the other ones a little too simplistic, probably
because they bundle all wavelengths into two bands, hence loosing information that I find important. This probably comes from my EE
background and remembering some of the details about filter design - there is No such thing as a perfect filter. Also, I would have loved seeing
the freq response curves for the Tiffen haze filter to confirm your recommendation.
As far as the filters that have freq response profiles in there, it would seem to me that it’s almost a toss when choosing between the B+W UV and
the Hoya UV. The tiffen lets in some UV, but it allows all desired blues to come in. The Hoya does a better job at cutting of the UV, but then
again also kills some desired blues, effectively warming the image just a tiny bit. Of course, this may be a desirable effect so it probably still is a
better option.
Anyway, thanks for another great and insightful article.
LuisB
-- Luis Bascones, October 16, 2003
Thank you Bob for this very informative article. Maybe some additionnal info: I checked the spectral sensitivity curve for my usual film, and
found that the blue layer is not so sensitive below 400nm. So, before choosing a UV filter, you may want to check how your own favorite film
does react to UV, in order to get an idea of the whole thing. I also thought that most modern Multi-Coated lenses had good UV filtering in it, so
this could also affect your choice. Olivier
-- Olivier GALLEN, October 16, 2003
Hi,
Thanks Bob, for an informative article.
Since this discussion is with reference to the Blue layer in film I was wondering whether it applies to the imaging sensors in DSLRs as well.
Put in another way, does UV light affect the imaging sensor of the DSLR enough to cause color shifting ? I have noticed a blue cast on some my
images on my 10D and maybe the reason is that I did not have a UV filter on.
The attached image is stitched panorama where all the individual images seem to have the blue cast.
Regards, Hemen
Image:PhotoNet_Aruna-Parth-Neptun.jpg
-- Hemendra Chonkar, October 16, 2003
Great document, uncle Bob! Would it is sensible to assume that there is a difference in UV absorbance between film and digital?
-- Yaron Kidron, October 16, 2003
Outstanding article!! But after reading it, I find myself no closer to answering the simple question that I'm sure all of us have: should I use a UV
filter, and if so, when? Thanks to this article, we know that some filters do actually remove some UV. But does this make a visible difference in
any real-world situation? Can anyone post examples, with and without a UV filter, where there is a perceptable difference? If such examples
exist, can anyone categorize the situations where a UV filter will make a visible difference? And of course, how do various films differ in
sensitivity?
-- John Ampe, October 16, 2003
An article like this should be published in one of the major photography magazines, but probably won't be because it makes clear the fact that
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