Allan Brown wrote in message <67m5qt$4hn@freenet-news.carleton.ca>...
>"Fred Whitlock" (afc@cl-sys.com) writes:

>> The purpose of UV and skylight filters is to protect your lens from dirt
>> and damage.

>Is this really necessary? Has anyone ever damaged the front element
>of their lens?
>
>I have been in photography for more years than I wish to admit to and
>have never damaged the front of my lenses nor have I ever met anyone
>who has. The closest event I had was while walking down the street
>someones bag banged into the front and cracked the lens cap.
>
>My cameras have been dropped, bashed rained on etc. and yet no damage to
>the front element. I even bought a Minolta rangefinder with a big dent
>in the filter thread - no mark on the lens.
>
>I think putting a relatively cheap piece of glass in front of an expensive
>lens "just to protect it" is nonsense. What is the lens cap for? to protect
>the filter?
>
>I use filters when I need to filter the light, not the environment. That is
>the job for the lens cap!


Hmmm, OK, once again... (but maybe for the very last time...!):

A good-quality (NOT necessarily expensive...) UV filter has
NO ill (or good!) effect on the film image under virtually
all conditions, "theories" about the optical or filtering
advantages or disadvantages of using a UV filter
notwithstanding. Period. No "haze cutting', no "softening",
no "lowering of contrast", no "flare increase", no "loss of
light", nothing... (under most conditions). It *may* be
advantageous to use a multicoated filter when shooting under
relatively rare lighting conditions, like straight into the
sun with a long lens. It is advantageous to use a coated
filter under some conditions. I prefer filters with thin,
but high-quality metal rims, though this has nothing to
do with image quality. I do use filters for protection.
I have had lenses grabbed (and the filter scratched),
and, careful as I am, I have scratched filters while
cleaning them (I prefer not to scratch lenses instead,
since scratches demonstrably *do* sometimes affect image
quality...). I am an image quality nut, and I find *NO*
disadvantage from using good-quality UV filters (with
well-designed and well-made rims) on most of my lenses.
BTW, to check the above, I set up a 400mm f3.5 ED
tele (used at f3.5 - a long and fast lens is a good
test for filter flatness), shooting a detailed hillside
a couple of miles across a lake. Images taken with the
lens alone, with one UV filter in either the rear or
front position, or with one on both the front and rear
of the lens, showed *NO* difference in sharpness,
contrast, haze-cutting, ETC. And, yes, I do use a lens
cap or shade to protect the filter...;-)
--
David Ruether
http://www.fcinet.com/ruether
ruether@fcinet.com