Avoiding Condensation


Today’s Question: I have often read that you should seal your cold camera in a bag before bringing it into a warm area and wait until it comes to room temperature. Could you expound? How cold? How warm?

Tim’s Quick Answer: If a cold object is moved into a relatively humid environment, condensation can form. That condensation can potentially cause harm to the camera, such as by causing a short circuit. Sealing the camera in a bag, preferably with a desiccant, can help ensure no condensation forms on the camera. My general rule is that if you need a jacket when you’re photographing, and then are comfortable taking that jacket off when you return indoors, it is probably sensible to take extra steps to avoid condensation.

More Detail: The bigger issue here relates to the dew point, which in turn relates to relative humidity levels. Because warm air is capable of higher humidity levels than cold air, in general there is some degree of risk when bringing a cold camera into a warm environment.

Obviously if a camera has been exposed to cold temperatures for any significant amount of time, the camera itself will get cold. When you return somewhere warm, the humidity in that warm environment can quickly condense on the cold camera, causing potential problems. How much risk there is depends on the humidity of the air.

In theory you can use the dew point to inform your decision about when extra care is needed to avoid condensation. In reality this is more complicated than it might seem. The dew point is calculated based on current weather conditions. The closer the dew point is to the current temperature, the higher the risk of condensation. But the reported dew point relates to outdoor weather conditions, and the conditions may vary significantly indoors where there is heating and air conditioning.

Because of these complications, my recommendation is to be relatively conservative, and to employ some simple guidelines. In short, if the weather outside is cold enough that you are more comfortable with a jacket, and if the conditions you will return to indoors are warm enough that you can comfortably remove the jacket as soon as you are inside, then you should put your camera in a bag before going indoors.

The best approach to avoid condensation on your camera is to put the camera into a bag with an airtight seal while you are still in the cold environment. Putting a desiccant into the bag will absorb any existing moisture, helping to further reduce the risk of condensation. Once the camera is sealed in the bag, you can bring that camera indoors and allow it to come up to room temperature. Under circumstances where this approach is most necessary it will likely take an hour or two for the camera to return to room temperature. Once the camera has warmed up to the current conditions, you can remove the camera from the bag.

It is possible to achieve a good result without the desiccant packs, but I prefer to make use of a desiccant to help minimize the risk of condensation on the camera, especially when photographing in particularly cold environments. For example, these desiccant packs provide a good solution for this type of use: