Carrying my e30 and Oly 12-60 lens in a Tamron Velocity bag, took a tumble off the car seat onto the pavement, thought nothing of it. It didn't fall hard, just sort of slipped slowly down. A couple days later - shooting into the sun thought there was much more flare than usual... looked down and the filter was shattered. Carefully unscrewed it, tossed it and kept on shooting. $90 filter saved a $900 lens.
ALL my lenses have a protective filter except the kit lenses, which can be replaced for the cost of a filter, and the 9-18 which will vignette with it.
I don't use the lens hood on that lens because it is simply too stiff to take off. Now I need to free up the lens hood so I don't feel as if I'll break the lens in half if I want to remove it.
Olympus e30, e-510, 12~60, 50~200 ED, EC14, 18~180, 14~42, 40~150, 50mm macro, 9~18, fl36