Originally Posted by
Tannin
Oh, and I should mention that the effect of a good quality clear filter is so small that some of the very, very best lenses money can buy come with what amounts to a clear filter permanently mounted as the first element. Yes, the big white $10,000 and $12,000 L Series primes - lenses like the 400/2.8 and the 600/4 - have a plain glass front element with no optical purpose: it is purely there to protect the (very expensive!) first optical element. If you should be so unfortunate as to damage your front element, the replacement part is worth only a little, where the real front element might cost five or six thousand to replace.
Having argued the case for filters at some length now, honestly compels me to say that, when you get right down to taking pictures, I can't quite bring myself to do something (put a filter on) that I know will reduce my image quality. (Even though I'll never be able to see that difference 'cause it is so small.) This is not logical. So shoot me!