Are your lenses always fogging up in the winter?

After so many days shooting in the snow and sub-freezing temperatures this year I thought it might be good to share a few lessons learned about keeping your camera functional and ready to shoot in winter.  

The key to understanding fogged lenses is that it only happens when you bring a cold camera into a warm environment.   Meaning that one never has problems when bringing a camera from the warm car/hotel room out to shoot in the cold.   In Yellowstone several times I pulled out my room temperature camera and began shooting early morning photos when the temperatures were below zero (easily a 70 degree temperature difference with no fogging issues).   But as soon as that camera cooled down and I brought it back to the warm car it would suddenly become a useless foggy mess.   The key is that once your camera is cold you need to keep it cold.  But be sure to pull the batteries out and keep them warm so they work.  

In Yellowstone we kept the temperature in the car just warm enough for our fingers and toes, but never warm enough to affect our cameras (I would take off my parka but leave on my hat, gloves, and fleece jacket).   My guess is that we kept the car around 40 degrees, and we often drove with the windows down while using binoculars to spot distant wildlife.   By keeping the car cold, we were able to leave lenses and cameras sitting out in the back seat ready for use at a moment's notice. 

         Drying my sleeping bag after a cold night, and yes that top number is correct it is 14 degrees at    
                                                                9:28am in the sun.   COLD!

At the end of the day when it is time for me to bring my gear into a warm tent, cabin, or hotel room, I always pack everything away tightly into my camera bags to help slow the warming process.   Not only is condensation a pain because fogged lenses can't be used till they warm, but moisture can also lead to electronic problems.   Some photographers even go so far as to wrap their gear in a plastic bag to keep out condensation until the equipment has reached room temperature. 

So remember, going from warm to cold is no big deal, but going from cold to warm is a BIG DEAL!   Also don't forget to keep that extra battery warm in your chest pocket!