An accident with some kids at a birthday party a few months ago resulted in my D200 with Nikkor 17-35mm f/2.8 falling 4 feet out of my open camera bag and onto a carpet-tiled floor with concrete underneath (lens front element first). I had the lens cap on, and that pushed into and smashed the UV filter. After some difficulty extracting the filter, and blowing off the glass shards with a hand blower, it was fairly clean. I replaced the UV filter and things seemed OK at first indoors, but then I went on vacation and a lot of my shots were overexposed so I had to do the best I could in the field to compensate. I ended up setting exposure compensation to anywhere from -2 to -5 stops depending on the situation (and sometimes used lower ISOs when 5 stops was not enough). Also, the wide end of the zoom ring (17-20ish) seems a little stiff, but at least it works. I haven't had a chance to check sharpness, but I think it's OK. It appears that the D200 body is metering correctly based on results with other lenses, so I think there is some internal damage to the lens. I saw a recommendation for APS when searching the threads, so I might use them, as I live in Chicago. If you have other recommendations, let me know. However, I'm curious if any experienced folks out there have comments on what might be wrong? I'm thinking something with the aperture mechanism, as the overexposure tends to happen when I'm using f-stops of about 8 or higher. Additionally, if you have other info on internal workings of this lens or lenses in general and where shock may be transferred during a fall, that would be educational as this is is good motivation for me to learn more. Do "pro" lenses have anything inside them to help with protection from damage in the field from drops? I know this is hard, but I'd assume if some basic features for dust protection and weather protection are designed for, maybe this situation is also considered during lens design. Thanks.