That's different - because again, it's not water, but water *vapor*. Vapor is a gas. The DA* 300, 200, and 50-135 will all have the same vapor inside unless you attach the lens before heading into the elements, and then don't detach until you get back.
The main issue is the humidity, and the only way to combat that is SLLLOOOOOOOOWWWWWWWWWWWW temperature adjustment (air conditioned to outside rainforest; cold overnight freezing to indoor heated domecile). I keep my gear in the camera bag for 6+ hours to adjust at a snail's pace - do it too quickly and then you get the "sweating can of coke" effect, mostly on the inside because the air will be warmer than on the len's surface. I notice this most in my distance scale windows.
What happens is the humidity (water laden air) changes into dew (droplets) because of the dewpoint, which is exactly what happens on your lawns, windshields, etc. every morning. This is why it is CRITICAL to allow your gear to 'stabilize' slowly when transitioning between extreme temperature/humidity difference in environments (the two most common I explained above).
Also note that chemically (physically?), warm air has much more ability to retain water, which is why humidity levels in the winter never reach those in the summer, however summer levels can reach very low humidity (which is why 110F/43C in Arizona feels much better than 90F/32C in Florida/Costa Rica or any other place that has typically dreadful levels of humidity. The higher the temperature, the higher the concentration before saturation (actual wetness). This is the same reason why boiling water can dissolve more salt, sugar, etc. than room temperature water.
-Heie
Last edited by Heie; 01-07-2014 at 03:04 AM.