It's often a matter of personal preference, filter or not, hood or not. I use both on everything I own. The hood for flair, the filter for protection. A quick story. At my grandsons 6th birthday party, I took my D1X and a non-VR 24-120 zoom and SB-800. We were at a local chain pizza joint a week after opening. I had the camera sitting on the table, resting on it's back with the lens pointing up. You can see it coming, I'm sure. The new server was bringing a pitcher of cola to refill our drinks, hit the table with the bottom of the pitcher and dumped the entire 3 quarts of cola on the camera. About 1 1/2" of cola was floating on the lens. I picked up the camera, shook the cola off the lens/body/flash and patted it dry. That's it! No damage, no slow AF, no nothing, all three came out unscathed. Try that without a filter on a lens. A close friend was shooting moto-cross and took a rock the size of a golf ball in the center of the lens. Replaced the filter and that's it, no other damage. To me, it's cheap insurance. Just get the better coated filters and everything will be cool.