The amazing spectacle known as the Northern Lights is an experience you will never forget and if you use your camera correctly you will be able to share your experience with others.
The Aurora Borealis occurs in the North and the Aurora Australis occurs in the south. We are talking extreme north and extreme south close to the Arctic and Antarctic circles. The majority of activity forms a kind of halo at both ends of the earth.
Camera – almost any DSLR is suitable. The deciding factor is the ability to open the shutter for long periods. Check to see if your camera has a bulb mode and maybe invest in a cable. A tripod or any other means of keeping the camera still for long exposures is essential. Lens – if you are dedicated, choose a lens with a super wide aperture. I use a f1.4 lens although I rarely go past f2.8. Wide angle is best … quite simply, wide angle improves your chances of getting a shot and also the stars start to trail much later on a wide angle.
To increase your chance of a successful aurora hunt, you need to be aware of the weather. If it is cloudy on earth, your chances of seeing the aurora grow weaker. You can increase your chances again by eliminating light pollution. A really strong Aurora can be seen in the city, but you really need to get far away from the city lights to improve your chances. The moon can also work against you. If you can see stars you have a chance, if you can see the Milky Way, you have a good chance.
Get your camera set up so that it is easy to handle. I would suggest chest height. Using a flashlight make sure your cable is connected, your lens is set just short of infinity and the camera is level. Then turn off the flashlight and let your eyes adjust to the darkness. Then wait. You can use the waiting time constructively. You can practice with your bulb and find a good composition. Set your camera to f2.8 (or as wide as possible) iso 800 and take some test shots for 30 seconds. Do this in all directions but mainly due north (Aurora Borealis). You may start to see a green hue on your pictures near the horizon. This is a good sign and this is the part of the sky you need to watch.
As the aurora starts to get brighter you need to start adjusting your settings accordingly. Start by bringing down your iso. Always check the brightness of your image on the histogram and never rely on the camera preview screen. Your eyes have adjusted to the dark so an underexposed image will look fine – until you get it home!
If the whole sky explodes and the Aurora casts a shadow, you need to be quick to adjust your exposure times. The best Aurora shots occur during these brief moments. A faster shutter of 8 – 20 seconds will preserve some of the details of the display.
Sometimes you cannot avoid star trails if you don’t trust iso 800 and your lens stops at f4, you might be exposing for 2 minutes with a weak aurora. Generally it is preferred to expose for less than 30 seconds to prevent noticeable star trails.