Spots on the inside of my glass
During the trip to Inner Mongolia this month, I discovered water spots on the inside of the glass of my lens (Nikkor VR 600mm F/4G). Inner Mongolia was dry, but I spent five weeks during July and August in Sichuan and encountered much wet weather. Perhaps condensation occurred in the lens during the Sichuan trip and I only discovered the effects recently. I protect the lens with camouflage "skin" and a rain cover. I'll shoot for up to 20 minutes in a drizzle fully protected. I immediately seek shelter in anything more than a drizzle. When it was not raining in Sichuan it was often very humid. I remember at least one time when I emerged from a cool, dry, air-conditioned room into 30-degree C heat and 90 percent humidity. Condensation occurred on the glass that time, but my impression was that the condensation was limited to the outer surface of the glass.
The spots are hardly noticeable, and I doubt they have any effect on performance. Still, I'm worried.
Four questions:
1. What caused the water spots and how can I stop the spots from forming again?
2. How can I remove the spots?
3. What's your modus operandi when rain starts to fall? How long will you keep shooting in a drizzle?
4. Does high humidity ground you the way rain grounds you? Do you fear high humidity?