Your Nikons are working correctly. Any pair of binoculars can fog up on the outside. Even a $1,600 pair of Swarovski binoculars will fog up on the outside, when you breath heavy on them. Somemay bead more than others, depending on their coating. Optics being "fogproof" means the inside of the glass, and not outside. It's a big misonception made by a lot of people. I also have a pair of Nikon Monarch's. I think they are the best pair for the money, out there.