A bit of advice beginning photogs often hear is to get UV or skylight filters to protect their lenses. When I started out creating this pile of gear I call a camera collection I always purchased a UV filter with the lens. At some point my photo mentors convinced me that maybe keeping it on all the time wasn't such a great idea, and besides it was getting too expensive to make sure every lens/camera had one, so I stopped buying them, and eventually stopped using them at all. Eight years later, and I have yet to damage a lens in a manner where the filter would have protected it (knock on wood). I don't think it's a right or wrong issue, just curious to see what people think.