Cold Weather Care
For those of us living north of the equator, winter is just around the corner. Here in the UK that means even more rain and grey skies than usual, and for everyone it means lower temperatures. Like most electronic devices digital cameras are affected by the cold, which is a problem at this time of year because most people like to use their camera outdoors. If you look in your camera's user manual, somewhere you'll find its operating temperature limits, and these will most likely be in the order of 0 – 40 degrees centigrade. While the upper limit is unlikely to be a problem here in the UK for at least a few more years of global warming, the outside temperature frequently drops below freezing in winter, and in more northerly countries this is even more likely. So, does this mean that you have to leave you camera indoors from November to May? Will it instantly freeze into an amusing camera-shaped icicle the moment the mercury drops below zero? And what damage can cold do to a camera anyway?
The answer to these questions is no, no, and not much. The stated temperature limits recommended by the manufacturer are really only there to protect them from being sued by people who manage to melt or freeze their cameras by using them unwisely. They are more like guidelines for optimal performance. In reality there is plenty of anecdotal evidence of people using digital cameras in sub-zero temperatures without a problem. I've personally used a couple of digital cameras on a glacier in Iceland without causing them any damage, and while looking up facts for this article I found accounts from people living in northern Alaska who used digital cameras at temperatures as low as minus 40 degrees, where the main problem was the risk of losing fingers to frostbite.
That's not to say that digital cameras are completely unaffected by cold temperatures. Any device that uses electricity, especially one that runs on batteries, can have its performance altered by the ambient temperature. Several components of a digital camera can be adversely affected, but with a bit of care and preparation it is possible to work around these and still get good performance and results whatever the weather.
All types of batteries use a chemical reaction to produce electrical power, and the speed of a chemical reaction is affected by temperature. As the temperature drops the reaction slows down, which means that the battery produces less electrical power, and as it runs down it will eventually pass the point at which it is no longer producing enough power to run your camera. A 10-degree reduction in temperature can mean as much as a 50 percent reduction in battery performance, which means that your camera will run out of power more quickly when it gets cold. Different types of batteries are more or less susceptible to this effect. Cheap copper-nickel and older Ni-cad rechargeables are affected the worst, but even high-power alkaline batteries and Ni-MH batteries suffer from severely reduced performance in cold weather.
Lithium and Lithium-ion rechargeable batteries are affected the least, which is good news since most digital cameras use this type of battery. If your camera runs on AA batteries I strongly recommend buying Energizer Lithium. Not only do they last up to seven times longer than alkaline batteries, they are half the weight and are much less affected by cold weather.
In order to keep your camera running in cold temperatures, it's a good idea keep spare batteries in an inside pocket under your outer layer of clothing, where they'll be kept warm by your body heat. When the battery in your camera starts to fade, swap it for the warm one and carry on shooting. You'll find that warming up the cold battery will restore it to life, so you can swap the two batteries over several times.
For really cold conditions, separate external battery packs are available to fit many high-end cameras, which can sit in the warmth inside your coat supplying power to your camera via a cable. Some of these require a dummy battery with a power socket to be fitted, but if so it will usually be included.
In extreme cold conditions, you may find that your LCD monitor becomes dark and refreshes more slowly, or even stops working altogether. This is due to the effect of the low temperature on the liquid crystals that make up the display, making them slow and unresponsive to the signals that usually power them, and unfortunately there's not a lot you can do about it apart from keeping the camera warm. The good news is that it has to be really cold (minus 10 degrees C or lower) for this to happen, and once your camera returns to a more normal temperature the LCD will function as before. This is just one of those times when an optical viewfinder is a major advantage.
A major problem facing camera users in cold weather is condensation. Condensation occurs when warm moist air encounters a cold surface. Warm air can hold a lot more water vapour than cold air, so when the cold surface causes a localised reduction in temperature, this water will condense out of the air and form droplets on the surface. If you use your camera outdoors, it will become cold. If you then bring it indoors into a warm room, condensation will form not just on the outside, but possibly also on the inside, where the moisture can cause damage to the electronic components. Even weather-sealed cameras are at risk.
The best and easiest way to avoid this is to find a large airtight Ziplock plastic bag, such as the freezer bags sold in many supermarkets, pop in one of those silica gel packs that come with new electrical equipment, and carry it with you when you go out taking photos. Before you come back indoors, put your camera and any moisture-sensitive accessories such as lenses into the bag and seal it up. This way, when you come inside the condensation will form on the outside of the bag rather than on your camera. Leave the camera in the bag for at least twenty minutes, until it has returned to normal room temperature. The silica gel should be enough to absorb any moisture that gets inside the bag.
Wrap up warm
OK, so we've made sure your camera will survive the weather, but please also make sure that you keep yourself safe as well. The countryside of Britain may look very innocuous, but I used to be a member of a mountain rescue team, and I can tell you from first-hand experience that it's possible to get yourself into a dangerous situation just twenty minutes drive from a major city. If you're going out taking photos in any location where cold is likely to be a problem, take a few sensible precautions. Wear several layers of warm clothing, especially a hat, scarf and warm gloves, and take some waterproof clothing. If you're going out for the day take a thermos flask with a warm drink, and possibly some high-energy snack foods. A torch is probably a good idea too, since it gets dark surprisingly early at this time of year. Always tell someone where you are going and when you expect to be back, and if you have a mobile phone take it with you. I love all my readers dearly, and I’d hate anything bad to happen to any of you, so make sure to stay safe this winter.