Most photographers know the value of a good filter. They can incorporate quick, effortless changes to our photos and save us valuable correction time. They bring out the hidden, emphasize the minute, filter out the unwanted and the over bright.
But perhaps their most important role is that of protector. Filters are a dime a dozen, and though some of them can run to the fairly pricey, they're nothing compared to the camera lens. I discovered only moments ago that my two filters (yes, both of them got the axe it looks like) saved my truly valuable lens from certain death. The impact cracked both filters... a terrible waste, to be sure, but the lens is whole and intact and life can go on. Just a quick trip to buy a (far cheaper) replacement filter and all is well.
This is not subliminal advertising: use filters!