The other thing that a UV filter does is help get rid of atmospheric haze, which is not something easily done in post-processing. Keep in mind, though, that not all filters are equal. Spend the money for a good filter from a known brand, like Hoya's pro series, rather than generics. Here is an excellent site that carries many different kinds of filters, explains their uses, and the different qualities of filters available. If you buy a cheap filter without multiple coatings your images can be subject to ghosting and reflections. Which is what happened in this picture:Notice the pale triangle near her arm? That's a reflection from an inexpensive lens filter. Which proves another point... you're better off with no filter than with a cheap one. After all, you've spent hundreds of dollars on lenses, and you're going to put cheap glass in front of that to possibly distort your images? Granted, out of many pictures I have maybe 5 that have noticeable problems because of this specific issue, but why even lose those? Another type of filter that many people keep on their cameras at all times is a skylight filter, or warming filter. They have sort of a pinkish hue that warms up the blueness of outdoor light, and often give pleasing skin tones in very cool light conditions. They're another option, depending on where you're shooting. I hope this helped a little, thanks for your time. 🙂
In one of my very first posts I recommended strongly that you get a UV filter to keep on your lens all the time in order to protect your lens from scratches and damage, also to protect your lens from getting cross threaded. I realize now I probably should have been clearer about what skylight, haze, or UV filters do, and what to look for. Basically, both film and digital sensors are sensitive to UV light that our eyes don't notice. That is why sometimes your outdoor pictures will have a bluish cast. This is usually more noticeable at higher elevations, but also happens near water and is most noticeable on sunny days, even in the shade. With a digital camera you can fix this by fiddling with your white balance, or in post processing, but why waste time messing around with that when you can prevent it with a good filter and some forethought?