A UV filter can be a savvy investment for the vast majority of photographers. As most modern digital cameras come with a UV cut filter on the camera sensor itself, a UV filter which screws into the front filter thread of your lens, like Kenko's Air II UV filter, will have a minimal effect on your images.
So you may think it pointless attaching a filter to your lens which has a minimal effect on your shots... However, having the filter attached to your lens can be a brilliant protective measure to prevent dust, dirt, water or even greasy fingerprints getting on to the front element of your lens. It's also much more cost effective to replace a UV filter which has become scratched or broken than the front element of your expensive lenses.
