Reader's Comments - Index of - Free

Filters - UV or not UV?
is stronger than at sea level they are useful if you are shooting slide film. My guess is that if you're shooting print film or digital, any blue cast
caused by UV can be removed by small correction in printing filtration or by color balancing digital files.
On the other hand, if you're one of those people who really want a lens "protector", you migh as well get one that also blocks UV, since blocking
UV does no harm and may do some good under some circumstances.
-- Bob Atkins (www.bobatkins.com), October 19, 2003
It would be useful to find similar information about different brands of 81B-, 81C- and 81E-type warming filters, particularly for those who live
or photograph at high altitides where the blue cast in chromes is substantial.
-- Conrad Smith, October 19, 2003
Bob - as usual, a very well written and informative article. Thank you.
I first learned how essential UV filters are when trekking in the Himalayas. Especially when photographing in the shadows, my images clearly
took on a blue tinge. At altitude, a good UV filter is essential. Also, one thing that is easy to forget is that polarizer filters do not filter UV very
well. And since most people unscrew their UV filters before attaching the Polarizer, I recommend one of the new Pola + UV filters, especially if
you are photographing in the mountains.
-- Fabian Gonzales, October 19, 2003
Shadows going blue isn't always a sign of excessive UV. Shadows are normally illuminated only by the blue sky - which is of course blue - and
so shadow regions tend to be blue. Often you may be better off with a warming filter like an 812, which will block some UV as well as warming
the shadows. Of course it also warms the sunlight regions.
Excessive UV usually shows up as an overall blue cast in both sunlight and shadow regions - or so I'm lead to believe. I've not personally been
high enough in the mountains to notice the effect very much.
-- Bob Atkins (www.bobatkins.com), October 20, 2003
In reference to whether UV affects digital cameras' sensors or not, I've read that UV contributes to the purple fringing we see on high-contrast
photos. I have a G3 and 812 filter. Perhaps some experiments are in order. :)
-- Michael Clark, October 23, 2003
Odd that no one has hinted at what I understand a UV/Haze filter to be good for: filtering haze. My understanding is that atmospheric haze
effects can show up in a photograph that weren't obvious in the original scene, due to UV light scattering from atmospheric haze. Since the film
can respond to wavelengths invisible to the eye, we see it in the picture as haze that we didn't see when we took the picture.
Am I remembering this correctly?
-- Bryce JFG, October 24, 2003
Agreed Bryce. As mentioned above, color variations (blue cast from no or a lousy UV filter) can be adjusted in digital post production. Haze, on
the other hand, is more difficult, if not impossible to remove. I would like to see some "real world" before and after samples, esp. using the
Tiffen UV Haze-1 or the Hoya equal. I have noticed a big increase in haze in landscape photos with the Canon D60 compared to using film
(despite the use of L-series lenses).
-- Richard Stum / Kinesis, October 24, 2003
Maybe you have explained why these high altitude images are so blue.
-- J. Harrington USA (Massachusetts), October 26, 2003
Would you please refer to using Sky Light filter insted of UV.
Eli
http://www.photo.net/equipment/filters/ (9 of 12)7/3/2005 2:21:53 AM