Originally posted by rbefly UV and Skylight filters aren't used much with digital, they aren't needed for the optical correction they lent to film cameras and lenses.
I disagree - they serve exactly the same purpose with digital as they did with film - to cut through haze and filter UV light. They were never used for optical correction. Besides, film-era lenses can, and most definitely are, being used with digital bodies, so the idea that shooting digital has somehow eliminated the need for these filters is moot.
Color correction filters, on the other hand, are no longer necessary with digital.
(as a side note, the sensor in your camera is NOT digital at all - it is purely analog, just like film. The analog values from each cell are converted to digital later by a conventional A/D converter.)
Using UV/skylight filters for physical lens protection is where the debate begins, be it film or digital. I have been in both camps several times, but finally settled the matter (for myself). I use good quality filters in lieu of lens caps. Lens caps take too long to remove, and you have to fumble with them to find a place to put them. By that time, the moment is gone. The filter performs the function of lens cap, and does not need to be removed.
Filters CAN aggravate flare, but you can mitigate this with the placement of your shading hand or your camera position. Lens hoods can help in that regard, too.