Reader's Comments - Index of - Free

Filters - UV or not UV?
Sigma 70-300mm.. than what would be the best.. because what happens is as we increase the mm on lense i have found the haze also starts
increasing... i mean the picture comes out white in shade...i use +ve rolls... thanks!!! rest the information is really viatal for all..!!!
-- Arun Dangwal, December 28, 2003
As a note to Wojciech, the reason you may have noted the effect of UV more during your trips to NZ may have something to do with the nearby
hole in the ozone layer over Antarctica. Its just an assumption, but the increased UV levels that we're warned about (skin cancer, etc), may also
be more obvious on film.
Guess I'll be keeping that UV filter on my lenses then!
Adrian
-- Adrian MacGregor, January 22, 2004
I would love to have seen Nikon L37c and L39 filters and Canon and Pentax equivalents. Not that I would like a Nikon v. Canon v. Pentax war
but that I would consider buy filters from any of these companies if they performed in a way that I wish. The Nikon L39 filter is a non-multicoated
filter with greater UV filtering properties than the L37c. I greatly prefer multi-coated filters. I currently use Nikon L37c filters on most all
of my lenses.
I live in a semi-arid region and consider going without a filter for protection foolishness as dust is a constant problem. I do not like to clean a lens
frequently but a filter is more expendable. I surmise that those who do not use a filters for protection must live in regions with higher humidity
and that that humidity helps control dust.
Dust on the front element or filter can add considerably to flare and ghost. Removing a filter in extreme conditions should reveal a spotless front
element.
I also find that shading a lens when possible with a hand, hat or black card has far more effect in reducing flare and ghost than removing a filter.
For longer focal length lenses a bellows type or compendium lens shade is the silver bullet to slay flare and ghost.
-- David H. Hartman, January 25, 2004
Hey folks, interesting to know but there is still the matter of the quality of the glass - the coating. Anyone knows the quality of the tiffen haze-1
or the hoya - i know the hoya g-series is coated only on one site - this is suffiecient quality - i don't know if you really nedd hmc?
-- Nico Kamm, March 2, 2004
A simple way to test whether a "UV" filter is doing something or not in the part of the near UV which most concerns most photographers is to
put it between a blacklight and something fluorescent under same. A blacklight puts out most of its UV energy at around 365nm, so if the filter
doesn't have much absorption until down around 350nm then one won't see much change when the filter is between the blacklight and the
fluorescent "sensor". If the filter kicks in at 370nm or above, the material will appear much darkened - even almost black if the filter is close to
the material.
At sea level the difference between different filters may not be significant, but for those of us at altitude (up to 14,000+ ft here in Colorado) it
makes a big difference with all B&W films and many color films.
BTW - early in 2004 B+W was coming out with a new strong UV filter designated 415, which may appear to the eye as a faint yellow filter (like
a Wrattern #2B) since it absorbs below 415nm; the standard B+W 010 UV filter fails the blacklight test and thus doesn't have much absorption
until down below 360 nm. I've corresponded with the tech people at B+W on this matter and can forward on the curves and such data they sent
me for anyone really interested.
-- Chris Wetherill, March 3, 2004
I think the important issue is UV attenuation. An expensive, optically neutral, high-quality, B+W UV filter is a pretty lousy UV filter if it doesn't
filter UV. If you need a UV filter you *can't* buy the B+W because it *doesn't work!*
Strong language sure, but everything else is irrelevant if it doesn't work.
http://www.photo.net/equipment/filters/ (11 of 12)7/3/2005 2:21:53 AM