Here is some thing you might not know or maybe have just never thought of.
Have you ever noticed that on a cold morning when you get into your car the windows will have water ( condensation ) on the inside of your car? How about if you have something cold like a glass of cold water and it is a hot day the outside of the glass gets wet ( condensation ). This water build up always happens when you have two things that have very different temperatures because the cold pulls the moisture out of the warm air.
Your camera equipment is no different. Something I deal with on a daily basis here in FL is condensation. My equipment sits in an air-conditioned building over night and the internal temperature of my gear gets down to 75 degrees Fahrenheit. In the morning I walk out the door into 95 degrees and 90 percent humidity. Now the camera being made of metal, glass, and plastic does not change temperature immediately so it is basically like holding that cold glass of water. Condensation builds up fast. You can visibly see the condensation on the glass and through the eyepiece, maybe even feel the water on the metal parts of your gear, but what you can not see is the water that has formed on the components inside your camera like the sensor and circuit boards those are what you need to be concerned about most.
Now for the tip!
DO NOT TURN YOUR CAMERA ON.
Well at least not right away. The best thing to do is to take your camera out of your gear bag and let it sit for a few minutes (I do 15-20 minutes) so the internal temperature matches that of the air around you. It is extremely important not to turn the camera on during this time because small droplets of water my be sitting on your cameras circuit board and making contact across many different circuits. Adding an electric charge could permanently damage your camera. Some cameras have a “CON” icon that will flash on the LCD readout to tell you condensation might be present. Condensation is not only a summer problem so remember that if you camera is not the same temperature as the air around it you will have condensation. If you are out in the snow and go inside a warm house give your gear a few minutes to acclimate to this new temperature. I hope this tip helps protect your investment and keeps you out in the field doing what you love!
Get Out There!