Tonight after work the Goldfinches were at the thistles in the horse pasture so I grabbeb the 40D and 400 f/2.8 on a monopod and headed out. The camera and lens were in the house all day and outside it was close to 90 and very very humid. As I looked through the viewfinder the first time I was confused as the lens would not focus and had a momentary heart stoppage as realised the lens was fogged. Thankfully it was just the outside of the main objective lens and after a few minutes when the lens hood off in the breeze it cleared up. But this got me thinking . What is going on inside the camera with this heat and himidity change? Is this something I should be aware of and is condesation happening inside of the camera?