Viewing the Aurora Borealis (or Aurora Australis for those of you in the southern hemisphere) is an absolute thrill, and I consider it to be one of nature's most amazing spectacles. Capturing a photo is also a thrill, and to do so you need a combination of the right gear, a little bit of knowledge, and a massive amount of luck. I've been out in both the spring and fall for aurora, and learned a fair bit along the way. Here are some of the key items:

- Check the aurora activity. Visit spaceweather.com for aurora forecasts and maps. It is typically possible to get 2-3 days warning of an impending spike in aurora activity, although I have also had great shows on 'quiet' nights. The website is filled with lots of scientific explanations for the aurora, which really appeals to the geek in me. We are near the maximum right now on the 11-year solar cycle, although it is not a particularly strong maximum this time around. Nevertheless, from now until spring the viewing opportunities are going to be very good up north.

- Plan your trip. For me, the easiest place to go for aurora watching is Yellowknife, Northwest Territories. A 2-hour direct flight from Calgary puts you right smack under the aurora oval. You don't have to go far from town to get away from the lights, and the landscape is flat so you have a nice big sky. There are plenty of lakes to give you opportunities for reflection shots in the fall. Yellowknife has a relatively dry climate and the chance for clear skies in the spring and fall are reasonably good.

- Timing. I timed both our spring and fall trips around the new moon. However I've seen plenty of aurora shots taken with the moon out and they also work very well. Spring and fall are the best times to go. In the summer there is too much daylight, and in the winter it is just too darn cold. Even spring was a tad on the chilly side... our first night there in March was -37 C (without adding in the wind chill).

- Camera. This is one area of photography where good gear does make a big difference. A full-frame sensor is the best bet, since it allows higher ISO before noise becomes a problem, and can take advantage of a fast prime lens like the 24 mm f/1.4. If you own a 1DX or a 5D Mark II or III, you'll be extremely pleased with what they can do. I'm sure the 6D will also be excellent for aurora.

- Lenses. The 24 mm f/1.4 prime was pretty much made for aurora photography, in my view. It offers the speed and sharpness you need, and has a wide enough angle when coupled with a full-frame sensor. Often times an even wider angle view is useful, in which case you could add the 14 mm f/2.8 (if money is no object!). I rented that lens once and like it because it doesn't curve the horizon when you tilt it upwards. Personally I'm not too fond of fisheye-type lenses for that reason. Zoom lenses are a very reasonable alternative to the fast expensive primes. The 16-35 f/2.8 is great, and you can even use the 17-40 f/4 quite successfully. In all cases, be sure to remove the UV filter from the front of your lens. Otherwise you will get weird circular patterns on the sky that you can't remove in post processing.

- Tripod. A good steady tripod is a must, and a ball head is ideal. I use the Really Right Stuff L-plate system which allows me to quickly shift between horizontal and vertical orientation, which is very helpful as the aurora changes shape. A leveling indicator is also very useful, if not essential. I used the built-in level on my camera body, but you could also get by with a bubble level on the camera hot shoe.

- Accessories. A cable release is very beneficial, and essential if you plan to make time-lapse movies. Bring a spare battery, and keep it in your pocket if you're shooting in cold weather. The oversize battery on my 1DX lasted just one hour in the -37 C weather, but once I warmed it up it was good to go again. If you're shooting in warmer weather, make sure you have a lens hood on. Otherwise dew can form on the lens and wreck your whole evening. Bring a headlamp, ideally with a red filter on the light. You'll need it as you fumble around for the buttons on your camera. In cold weather, bring a big zip-top bag that you can put your camera in before going indoors, to prevent condensation.

- Image settings: Aurora can move quickly, so it's often best to get as fast a shutter speed as possible. Choose the highest ISO that you can tolerate (trial and error is your best bet here). If you are using a fast prime like the 24 mm f/1.4, I'd suggest stopping it down to f/2.0 to reduce coma and improve sharpness all around. It will still be plenty fast. For f/2.8 or f/4 lenses, I'd suggest going wide open. Then in manual mode, use the histogram to pick your shutter speed. Aurora brightness can vary quickly and tremendously... one minute you can be nailing the exposure, and the next it is completely blown out. Pay close attention to the green channel on the RGB histogram. You want to make absolutely sure that you are not blowing it out (i.e. touching the right side of the chart). Adjust your shutter speed accordingly. For my recent trip to Yellowknife, my most common settings were ISO 1600, 8 seconds at f/2.0. When we were there in the spring, the aurora got so bright on occasion that I could use a 2 second exposure. That was quite handy because the brighter the aurora, the faster they move. Long exposures would produce a big green fuzzball in those circumstances.

- Focusing: It is essential to use live view to get the focus right. Zoom to 10x magnification and adjust the focus until the smallest stars are sharp. Then lock the focus in manual. During the night I would re-check the focus several times to make sure I didn't accidentally bump it.

- Composition: Aurora photography offers great opportunity for generating creative compositions. I've seen awesome shots by other people where they incorporated trees, old buildings, and other such features into their shots. Use your spare time during the day to identify some interesting locations. And be sure to try vertical compositions as well as horizontal.

- Making movies: A fun thing to do with aurora is generating time-lapse videos. It's a piece of cake, really. Just set the camera on continuous drive, and lock down the button on your cable release. I use QuickTime to splice the images together, and a rate of 6 frames per second seems to work reasonably well. You should try to get at least 20-30 minutes of real-life images to create a decent time lapse. A wider-angle lens is often a better bet for time lapse photography, since the aurora can move across the sky rather quickly. The 14 mm f/2.8 prime would be a good one for this.

- Cold weather gear: Shooting at -37 C was outrageously challenging, especially with trying to keep my fingers warm. I found that the best solution was to use chemical heat packs, by the dozen. I had two layers for my hands: A thin glove inside a big fat overmitt. I tied the mitts together through my sleeves so I could pull them off without having to drop them. I used heat packs inside both the thin gloves and the overmitts. It was the only system that worked, but I still had to move very quickly when I pulled off the overmitts to adjust the camera. Taking photos in the fall with temperatures above freezing was so much easier. However we had terrific aurora shows in the spring, and I certainly don't regret going then.

- Post processing: In Lightroom, I might make a minor change to white balance, and add a bit of noise reduction. I also use the clarity slider to make the aurora pop a bit, and sometimes add a small touch of contrast. I don't add vibrance or saturation... I personally think that's cheating.

- Odds: So you've decided to head north (or way south) to see the aurora... what are the chances it will work out? On our trip in March, we saw great aurora on 2 of the 4 nights we were there. One night it was cloudy and one night was just really quiet. On our trip this month, we had a fine show on 3 of the 5 nights, with two of the nights being cloudy. And of the 3 nights that worked, two of those had zero wind so I could get the reflection shot that I so greatly coveted. So I think if you're going to be out there for at least 4 nights, your chances are pretty good you'll see something.

I hope that covers the major points... feel free to ask any questions if there's something that I've missed.