I was out shooting yesterday and it seems I now have a fogged up viewfinder.
Google has been useless.
I had this happen a couple months ago after walking in the rain, using it, then walking back out a couple hours in the rain.
I removed the lens and sat it in a warm dry spot and it had dried out by the next morning and was back to normal. It did have me quite concerned at the time, but it didn't suffer any further damage.
I was near Nikon HQ so I went in and got a sensor clean and asked the guys. He was concerned that there was moisture in there and said that it might damaged the circuits. His advise was to pop it in a container with a Hippo moisture absorber overnight.
After the clean another guy said that the hippo was going to be fine but not to worry about the circuits as it is a weather sealed body. As of now there is nothing in the viewfinder and the camera is resting with a hippo.
Stop taking Steamy Pics. LOL.
"Google has been useless." Yeap.
Did the viewfinder fog on the inside or the outside surface? this will help you understand whether you have weather in the inside, or just the temp difference causing it to fog?
it was on the inside
all good now.
FYI - I had a similar issue the other day, after leaving my camera in the boot of the car early in the morning until afternoon, I was very distraught to find "fog" in the view finder and lens.
I ended up using a hand dryer in the stadium loo to warm them up. ( not close, just close enough to get the outsides a little warmer).
This cleared it up, and I have not seen any moisture at all return.
Also I've found that placing wet electronics in a bag of rice overnight tends to do a great job at moisture absorption. (thankfully I have not had to do this to the camera yet..)
I have a container with a Hippo moisture absorber so my camera lives in there when not out and about.