How to Photograph Aurora Borealis (Northern Lights)
Photographing auroras can seem like a daunting task. Planning to shoot this phenomenon can require combining a little bit of astronomy with meteorology.
You will need some clear skies. Looking at a basic local forecast, you wouldn't want to see more than 50% cloud coverage. If the forecast looks clear, get an aurora map and you will be good to go.
Clouds can offer a challenge. You won't see auroras through with overcast conditions. To view current cloud conditions, you will need to use infrared satellite. Visual satellite only works during daylight hours and since we will be shooting at night, it is of little use. Intellicast offers a good IR satellite page. You can click the map to zoom into regional views. The brighter the white, the thicker the cloud cover.
With my experience shooting Northern Lights, their timing was pretty predictable. I watched the map each night for a couple weeks before my trip and noticed the earth simply rotated through a similar pattern each night. When I was in Iceland, this held true with what my eyes saw and the map showed. I used the My Aurora Forecast App and it was very useful. It gives you a visual map of where the auroras are peaking. The app uses your location to generate a custom aurora forecast including current and future KP index, cloud cover, and probability of seeing Northern Lights. Do note this app does not factor moonlight. I suggest shooting with less than a full moon. With strong auroras it probably wouldn't make much difference, but it definitely will wash out weaker displays.
The KP Index runs from 0.00 to 9.00, with 0.00 being no activity and 9.00 being a massive solar storm. Ideally I would want a KP of at least 3.00, but if it's lower it is still worth going out as aurora prediction is far from an exact science. Some of our best nights in Iceland had a KP of 2.00.
If you want to dig deeper into learning about the KP index and forecasting auroras, here is a great site to get started.
Location, location, location!
The closer you are to the poles, the better your chance of seeing auroras on and given night. Occasionally, powerful coronal mass ejections will send the lights further towards the equator, but if you want these types of shots, think about a trip to Alaska, Canada, or Iceland. Be aware of the amount of darkness available during your trip, as the summer months at locations near the North Pole see little to no darkness.
Light pollution must also be taken into account. While auroras can and are sometimes seen in cities, it takes a very active night to overcome city lights. Here is a good light pollution map to help you find some nearby dark skies.
Unless it is a massive solar storm, you are going to need a camera capable of long exposures. Whether it be a DSLR, mirrorless, or a smart phone, it needs to be capable of exposures of a few seconds or more. Better and newer cameras tend to handle low light photography better as technology continuously improves, with sharper and cleaner images. I shot the images on this page with a Canon 6D.
Of course, you will need something to balance your camera on, preferably a sturdy tripod. A remote trigger to prevent camera shake is also beneficial. Alternatively, you can use your cameras self timer function.
If your camera has interchangeable lenses, you will want a wide angle to capture more the sky. A "faster" lens has a wider aperture, which allows in more light, helpful when shooting in low light. Look for a lens with a minimum aperture of f/2.8 or f/1.4. I used a Canon f/2.8 L series lens for the images on this page.
Settings are going to vary considering the strength of the auroras, amount of light pollution, and the ability of your camera.
APERTURE - You will likely want to use the largest aperture (smallest number) your lens is capable of. If you are dealing with light pollution, the moon, or an incredibly bright auroras you may need to stop down (larger number) to allow in less light. While shooting in Iceland, I most often used f/2.8.
ISO - Your minimum ISO will probably be around ISO 1600. If your camera can shoot at higher ISO's with low noise levels, push it further. I most often used ISO 3200 to ISO 6400.
SHUTTER SPEED - While you will need to use a longer shutter speed, it won't be as long of an exposure as shooting the Milky Way. Auroras are much brighter than celestial objects and move rather quickly. You can see the green color and their movement with the eye, especially when they are more active. For bright pillars and bands near your location, you will need an exposure of 5 seconds or less. Faint aurora, called "Deepcloser to the horizon may require a little longer exposure of 10 to 15 seconds.
If you expose too long, it will cause the auroras to blur and appear as a wash of color in the sky of your image. Too long of a shutter speed could even cause the auroras to blow out (be too bright and appear white). Consider these unedited, straight out of camera jpegs. The left image was shot at 4 seconds. I took the right image immediately afterwards with an exposure of 25 seconds, to assure I had enough foreground detail for my final image.
FOCUSING - You will need to be focused at infinity on your lens. Be sure you are switched to manual focus, as autofocus will throw you out of focus. If you do not know where infinity is on your lens, turn the preview on your LCD screen and use the controls (not the lens) to zoom in on the screen. Rock the focus Be sure to have any camera or lens image stabilization turned off.
IMAGE QUALITY - Be sure to shoot your images in RAW format if available. This enables you to alter the color balance after the effect with no quality loss. If you do not have RAW as an option, set your color balance to "Fluorescent".
Making Better Aurora Pictures
Find a compelling foreground. There are countless aurora images made by incredibly talented photographers. Do something to make yours stand out. A person in the foreground or a great landscape will add interest to an already dramatic image.
Finally enjoy the experience. Viewing auroras is an incredible phenomenon. Try not to get too caught up in taking pictures and enjoy the moment!