Let’s face it, finding fog or haze inside your lens is heartbreaking. It takes hours for the fog to clear out. While fog has little effect on image quality, it can have a severe effect on the internal elements of your lens.
Fogging essentially means that there is moisture in your lens. If that moisture stays for too long in a cold environment, it may freeze mechanisms in the lens or develop lens fungus. For some cameras, it may also cause unsharp (vignette-like) images around the edges. In other words, a photographer’s nightmare.
So, what is the science behind fogging of camera lenses in cold seasons or regions? It’s simple. Warm air holds more moisture than cold air. The colder the warm air gets, the less moisture it can hold, condensing it into liquid instead of vapor. Inside your house or car is much warmer during cold seasons, thus our camera automatically acclimates to that air temperature.
When you take it out, the air touching the camera body drops several degrees, condensing water all over the camera. The air temperature at which the air will condense is known as the dewpoint and this depends on the humidity of the air. For instance, if the air temperature is 85F and the dewpoint is 84F, your camera will likely get moist.
Therefore, the trick is to raise the air temperature above the dewpoint while preventing warm, humid air from coming into contact with the camera. In other words, it’s about keeping your camera lens at a lower temperature to suit the cold conditions. Read on and find out how to prevent your lens from fogging in the cold.
Related Read: How to Get Water Out of Camera Lens
1. Keep your camera outside
Sounds a bit risky, right? Well, yes, but keeping your lens outside doesn’t necessarily mean leaving it out overnight. It should only take half an hour or less, provided you are in a safe environment. That way, you won’t have to worry about burglars stealing your camera. If your shoot is, say, seven o’clock, you can wake up a bit earlier and place your camera outside as you prepare.
But why put your camera lens outside? Putting your lens outside allows it to equalize with the surroundings, which helps to stop condensation from forming when you need it. The lens fogs up and defogs before you start shooting. There are two safe ways to leave your camera outside.
The first method is to place your camera lens in a camera bag (along with the camera and other gear) and put it outside. Another alternative is to put your camera lens in a zip plastic bag or sealed case and place it out. Ensure the zip bag does not have any air and seal it tightly.
Once your lens has acclimated, ensure you pack it in your camera bag while it is still outside. Packaging it in the house or car will reverse the acclimation all over again in warm temperatures.
If putting your camera outside is not an option, hand warmers are another great alternative to prevent your camera lens from condensing. Handwarmers are small packets that produce heat on demand to warm cold hands. These packets contain a mix of activated carbon, iron, water salt, cellulose, and vermiculite. When they are exposed to air, the iron oxidizes and releases heat in the process.
While inside your house or hotel, strap one or two hand warmers on the barrel of your camera lens using a rubber. Since your camera lens had already acclimated to the warm temperature, the hand warmers will help maintain that air temperature when shooting outside in the cold.
3. Don’t take your camera into warm areas
Once you start shooting in cold temperatures, do not take your camera back to the house or car. Remember switching between air temperatures is what causes condensation to occur. Therefore, you should not take your camera to warm areas in the middle of your shoots.
In this situation, preparation is key. Before you begin shooting, ensure you have the proper gear and tools. That way, you will have everything you need to avoid moving back and forth.
4. Pack up after shooting
It may sound obvious, but this process is essential if you want to avoid condensation. Before bringing your camera inside, put your camera lens in a zip lock or camera case. This is to protect it from ambient air.
While inside your house or hotel, it is inevitable that you will want to take out your camera to charge or transfer photos. Before doing that, take some time(preferably twenty minutes) to allow your camera lens to warm gradually.
Shooting during cold seasons or in cold regions doesn’t have to be complicated by fogged-up lenses. The best way to prevent condensation is to prepare by keeping your camera lens out, using hand warmers, avoiding taking your lens between warm and cold areas, and packing up after shooting.