Originally posted by sebberry is the coating on the front element on the exposed side or the inside?
Just wondering how bad wiping the lens down when it gets wet is, esp if there is some dust or salt water spray on it.
The lens elements are coated on both sides. The DA series have an increased anti-reflection coating on the element nearest the camera to reduce somewhat reflections of the sensor to lens. The later ones also have a harder front coating that is supposed to be more resistant to abrasion.
Dust is no problem on the front element of a lens. Just blow it off. If it is really stuck on there, use a microfiber cloth dampened with isopropyl alcohol, and wipe it very gently.
Salt water is extremely corrosive, and should be rinsed off with fresh water as soon as possible. My KX (the film one, not the digital one) and lens were whale splashed at a display. My family laughed their collective heads off as I missed three quarters of the show using cloth and clean water to clean the equipment off, but it survived just fine. If you dunk your camera in salt water it is generally a write off. Perhaps a quick dunk with a k10, k20, k200 or k-7 with weather resistant lens could be rinsed off under a tap without damage to the camera.