Originally posted by F-Stop
Personally I wouldn't waste the extra on WR lenses as the sealing is pretty poor. It's really only good under light drizzle or an infrequent/accidential splash. I had my 18-55 WR out in the rain for only a few minutes and the front laminated elements hazed inside. The front seal is nothing more than a cheap piece of felt pushed in place covered by plastic finishing ring. There's no special rubberized o-rings to keep water out except on the mount. WR lenses are mostly insurance to the body, IMO. I e-mailed PENTAX Canada with photos and asked how to resolve yet never received a reply. I just put the front element in a vacuum sealed container with silica gel bags overnight and it was fine. The DA* line has better sealing yet high priced and limited selection.
Hazing is an indication of temperature change, and thus condensation. If your WR lens was actually affected by the rain, it wouldn't "haze", you would notice water droplets within the lens.
Condensation is a nearly unavoidable effect of temperature change regardless of the lens you use, be it DA* or WR.