Quote Originally Posted by conropl View Post
Brant gave a good run down of the filters out there and there uses. One he missed is not really going to help you photos, but is more intended to protect your lens... and that is the UV filter. There is a lot of debate over there usefulness, but they do protect you front element from get bumped, smudged, or sand blasted in heavy wind. I would rather clean my UV filter than have to scratch coatings on my front element by rubbing it.
I'll fill in the missing counterpoint: the debate should also point out that the UV filter impacts the quality of your shots. Every air-glass interface is an opportunity for reflection, distortion, and "loss" of light. Lens makers go to great lengths to figure out the ideal shape of every element, so putting a piece of flat glass in front of those perfect shapes might not be the wisest choice.

Two key data points I feel compelled to contribute:
1) Visit http://www.lensrentals.com/blog/2011...th-bad-filters to see the effect of 50 filters stacked, then to see the effect of 5 bad filters vs. 5 good filters vs. no filter.
2) I can't seem to dig it up with a quick search, but lensrentals.com ran the numbers and determined that the cost of repairing lenses with drop damage costs less than putting a (premium) filter on every lens.

Obviously, I'm anti-UV filter in general, though I do slap them on every lens whenever I go sailing with my dad. I don't want the water spray on the front element. I'd do the same if I shot at the desert.