There's going to be as much debate about filters as there is over film vs digital. Short answer is, everything has its place.
I got a cheap Tiffen UV for my general-zoom when I got my first (d)SLR. After a few months and a few tests, I got rid of it. I could actually see the difference that it made to lower IQ (not only the vignetting at the wide end).
But then a few years later, I got the new Canon EF 70-300L, and put on a B+W MRC filter. Testing and pixel peeping with and without, there is absolutely no difference to IQ. Not only is it better glass, but it's multicoated (unlike the cheaper ones), and it's easier to clean with some fancy coating.
Sure, lens hoods protect against falls, but lens hoods also tend to prohibit using CPLs (in general, but I hear Pentax makes a nice one with a cutout). And lens hoods just won't protect against sandblasting. Maybe you don't go down to the beach and shoot surfers, but I do. It's dusty and windy and sandy here in Aus.
So if I'm going to shoot surfers or birds on the beach, it's UV and no hood (sometimes with CPL, I've also got a nice KSM CPL for that lens). If i'm shooting indoors on stage (with lots of incidental light from the roof), it's hood and no filter (well, sometimes filter, like I said there's no IQ loss so sometimes I just leave it on. And yes, I know a 70-300L is hardly a fast indoor lens, but if i'm using Delta 3200 there's no harm in going an extra stop to 6400).
Also, see this: http://www.lenstip.com/113.1-article...ters_test.html
tl;dr: B+W MRC are good. Tiffen are junk. Good Hoyas are good, bad Hoyas aren't. Marumi ain't bad.
I would use a UV filter if I felt it would be necessary for exposure control. Example, suppose I felt that I needed the extra precision offered by (also debated at length ... a Zone VI modified light meter). One of the interesting stories that Fred Picker told about the Zone VI modification is that, although he did include an IR blocking filter, he did not modify the meter on the UV end of the spectrum. For this, he said, you use a UV filter on the meter... and a UV filter on the camera. If I didn't want to make Fred turn over in his grave, by gum, I would use a UV filter if I used a Zone VI modified meter.
I've been known to put the odd fingerprint where it doesn't belong, so I sometimes appreciate having an easily cleaned filter in front of my lenses.
Here's what I do with my lenses.
For all of my lenses, I have either NC (no color) or UV filters on them. I only use quality filters and most of them are Nikon branded NC type. As soon as I receive the lens, I inspect it and clean it if necessary, then the filter goes on. They don't come off unless I have a reason to do so.
I'm sure this thread will soon evolve into lengthy argument as it always does. I know what works for me and I stick with that.
I use one to protect my lense if using color. If I'm using B&W I use yellow or orange, red.
In all of photography, I can't think of a subject where so much has been written about such a minor issue. Personally, I use protective filters only in adverse environmental conditions, but doesn't mean that's right for anyone else.
Lens hoods, filters, and insurance each provide overlapping but different types of protection. A lens hood can deflect some incoming dangers, assuming they come in at the correct angle. They can also absorb some energy from a drop, and act as an "early warning" system when you are about to strike an obstacle. But when grit from a dirt bike or salt spray is coming at you, the lens hood isn't nearly as useful. Both hoods and filters work best against small "day-to-day" traumas, but for gear-destroying events, "all risk" insurance is your best bet.
I've personally owned two lenses where I've picked up "cleaning marks" on the front element which a filter may well have prevented but a lens hood did not. The effect on lens performance of the marks is negligible; the effect on resale value much less so. One lens I sold at about a $100 discount off of a copy with clean glass. The other, a Nikon 180mm f/2.8D, went begging at the same reduction in price. Nor does insurance cover such losses; it's rightly considered normal "wear and tear."
On the other hand, quality filters are not inexpensive, and adding even the best filter increases the likelihood of flare spoiling your shots. Compared to a clear protective filter, UV filters also block a small amount of additional visible light in the violet range. My tests showed that adding an B+W MRC 010 reduces overall transmission by about 1.8% and imposes a color shift of about 25 degrees K. These aren't huge effects, but there's no compensating upside unless you:
(I do both, which is one reason I haven't swapped out my 010 MRC's).
- shoot either non-chromogenic B&W film or tungsten balanced color film AND
- shoot either 25+ year old lenses or simple Tessar-like lenses.
In the end, it's your gear, your shots, and your money. If you feel uncomfortable enough using a lens without a filter that you start missing shots, then by all means use them. If, like me, you're willing to accept that lenses are tools, and that cosmetic wear and tear is part of the deal, then don't. No matter how long people argue about it, there's simply no "one size fits all" answer.
I have a $95 UV(Haze) Kenko Zéta on all my lenses (alternates with B+W Kausmann C-POLs). I have never, not ever put a $5.00 filter on a $3,000 lens, as much and often as I observe others doing that. It's much easier to wreck a reasonably expensive filter than to wreck the front element of a lens, that's for sure. That is the guiding philosophy of providing protection, if not function (but a UV filter will reduce the excessive blue at higher altitudes; for everyday use though it has little visible effect and should be there for the protection of the front of the lens, no less). Filters do introduce an additional risk of flare and ghosting that can occur more easily, particularly with aspherical or apochromatic front elements.
Kent in SD
Thank you so much for all your opinions. I wasn't expecting so many posts! I suppose it all depends on the conditions at the time of taking the shot. I just got so used to having the UV filter on all the time that I never considered taking it off, especially as I use rangefinders, so I'd never miss a shot due to forgetting to take the lens cap off! For landscapes on a tripod, I'll take the filter off for the shot in future and see if I can spot any difference.