The end of summer means many things to those living in northern climates, but one of the more exciting is the perennial return of the northern lights. That's not to say that the lights haven't been active all summer, just that it's been too light to see them until now.
Here are a few tips to make the most of a late-night photo excursion.
First, pick a spot away from city lights. If it's a clear night, it doesn't even have to be that far away from town. Some of my favorite spots in Southcentral Alaska are the Old Glenn Highway along the Knik River, Turnagain Pass and Hatcher Pass. Pick a spot that offers a clear view of the sky, ideally looking to the northeast.
Once you have a general spot in mind, take out your widest lens, and remove any filters you have on it. Many filters can cause concentric rings to form on the image when capturing long exposures at night.
Next, choose a foreground element to include in your photo. Photos that capture only the sky can be great when the aurora is very active, but oftentimes including a foreground element like mountains, a tree branch, or a river can provide an important sense of scale, making the aurora feel bigger. Make sure whatever foreground element you choose is low in the frame, allowing most of the photo to be filled with sky.
With your camera on a tripod and the scene set in your viewfinder, the next step is to focus the lens. At night it can be nearly impossible to use your camera's autofocus feature. Be sure to turn off autofocus, and instead rely on manual focus. Find a distant bright object, like a far-away streetlight, or the north star, and slowly change focus until it is as sharp as you can get it. If you have a newer digital camera that offers a live view feature, that can make this process much easier.
By now you should have your camera nearly ready to start making pictures. Begin by running a few tests to dial in the exposure. A good place to start is at ISO 1600, 10 seconds at f/2.8. The shorter your shutter speed, the more distinct the aurora's ribbons will be. An equivalent exposure with a shorter shutter speed would be ISO 3200, 2 seconds at f/1.8. I generally leave my white balance set on the daylight setting, but if you prefer a bluer sky, try putting it on tungsten.
Now that you have everything dialed in, prepare to be patient. If you have a cable release, set it to continuous mode and let it run for a while. If they are faint, the northern lights can be tough to spot with the naked eye, but they can show up on the back of the camera. If you don't have a cable release, see if your camera has a self-timer. The goal with either technique is to minimize any camera shake that can add unintended blur to your photo.
Do you have any tricks that have worked for you? Any favorite spots to view the northern lights? Leave them in the comments.