Hints that winter is on the way, falling in parts of Maine last weekend, provide a not-so-gentle reminder that it’s time to think about keeping your camera running when you’re out there having fun in all of that cold.

Every year about this time, an article in some camera magazine tells folks that the way to do that is to keep their cameras under their jackets and only bring them out to take a picture.

That’s partly because camera batteries generally perform less efficiently or not at all when exposed to freezing temperatures. It’s also partly because the writers of those articles aren’t as active as the readers of this column.

Anyone who snowshoes or cross-country skis know that when you travel under your own power, you work up a sweat. What do you think happens to your camera if it’s under your jacket with all that moisture? And what do you suppose happens when a wet camera meets cold winter air?

You cannot avoid exposing a camera stored beneath your jacket to some moisture if you are an active person. On the wrong day, that moisture can freeze up your zoom lens, screw up your autofocus, or fog up your lens surface.

An even worse problem might develop if you shove a camera that’s been out in freezing temperatures under a warm jacket or into any other warm place right away. Condensation collects immediately on the body and the lens’ outer surgace and – worst of all – might even form on the inside of the lens barrel itself. Little green things that can etch glass might someday grow on the inside lens surfaces from moisture trapped in the lens barrel.

So how do you keep your camera going when you’re out there “going for it” in winter? It’s easy. Just keep your camera outside your jacket and let it become as cold as the outdoors.

Most modern 35mm cameras will operate just fine, even in sub-zero temperatures, as long as their batteries continue to provide power. Your focus – pun intended – should be how to keep your batteries working, not how to keep your camera warm.

Several ways exist to do just that. The easiest and cheapest method is to keep a spare set of the batteries that your camera requires in a pants or shirt pocket. Be sure to wipe off any moisture before you put them in your camera.

You can also buy batteries that perform better in the cold. Lithium or nicad batteries are available for many camera models. Lithiums perform better longer in lower temperatures. I have a set of lithium batteries reserved for the coldest days, as well as several sets of AA-size nicads, the type that you can recharge, for the average Maine winter day. I always keep a spare set of the nicads warm in a pants pocket when out on a cold winter’s day.

If it’s really cold, say below zero, I also take the full battery clip out of my camera and keep it warm in a pocket until it’s needed for shooting. That method – developed out of necessity while on a six-mile hike in 20-below zero weather in Baxter State Park last winter – gives you two chances to keep your camera going.

And if your camera dies because the batteries got too cold? Take them out and warm them up in your pocket. If you have an all-manual camera that has only a tiny battery to operate the meter, you can sometimes warm that battery up by rubbing it between your hands for a few minutes.

You should always bring your camera up to temperature gradually when you’re done enjoying the winter.

If you’re getting in a car, put your camera gear in the back seat and cover it with something to protect it from the heater. I put my cameras inside a waterproof plastic case so that they’re not exposed to condensation as they warm. A tightly-sealed plastic trash bag works just as well by collecting condensation on the outside of the bag.

Next month we’ll review how to get great exposures despite all of that snow that’s trying to fool your camera’s meter. Then you’ll be ready for a white Christmas. Until then, keep shooting and catch them in the good light.