How to photograph northern lights

northern lights in turku archipelago finland — Northern lights in Turku archipelago, Sony A7 III, Samyang 14mm f/2.8, 5sec, ISO640, f/2.8

Northern lights photography

Photographing northern lights can be challenging, but rewarding. They are hard to predict accurately and the conditions are usually less than optimal for photography. It’s dark and cold. You’re tired. You see that faint green arch in the northern sky that has been there for hours already. Then you notice that it starts rising higher in the sky. It’s getting brighter. That’s when things start to get interesting.

But how did we get to that point?

When there will be northern lights?

Without going too deep in to the science of northern lights, they are caused by solar wind disturbing the earths magnetosphere. Here in southern Finland (60 degrees latitude), where I live, we need more than just the basic solar wind that is blowing all the time. We need sunspots, coronal holes and coronal mass ejections (CME) to give that solar wind a boost.

So how do you know when that happens? There’s satellites in space that are constantly monitoring the suns activity and lots of great websites that report what those satellites measure. I’ve put some links of those sites at the end of the page.

When predicting a good night for northern lights you can use the KP-index forecasts found on most of those sites. They aren’t that accurate, but definitely better than nothing. When that night finally comes, when there should be northern lights, you can use those same sites to follow the solar wind speed, solar wind density and Bz-Bt -values. Basically you want high speeds, high density and negative Bz. It takes some time to learn to interpret all those readings, but once you get a hang of it, it helps a lot in planning and timing your photoshoot.

Obviously weather forecast is as important. If it’s cloudy, you need some other reason to go out that night.

Where to photograph northern lights?

You want a location that has as little light pollution as possible. If you can’t get to a place that is totally dark, try to find a location on the north side of the worst light pollution, ie a north side of a city. Unless you are somewhere up in the arctic circle, northern lights usually appear above the northern horizon. The stronger the solar storm, the further south the northern lights spread.

So you want a dark location with a good view to the northern horizon.

Camera gear

Even a modern smartphone can capture the brightest northern lights, but for good pictures you want a camera. Preferably a full-frame or APS-C camera with fast and wide lens. Tripod is essential like in most kind of night photography. Remote shutter release is helpful to reduce camera shake.

My recommendation for lenses when photographing northern lights is fast (f/2.8 or faster) and wide (20mm or wider) lens. Of course it depends on what kind of images you want. If the whole sky is lit up and you want to capture everything, you probably need a fish-eye lens. But sometimes it’s nice to zoom in on details with something like 35mm lens. Just remember to adjust your shutter speed when zooming in to better stop the motion of those northern lights.

Check out my gear page to see what lenses I use for northern lights photography.

northern lights in southern finland in winter — Northern lights

Sony A7 III
Samyang 35mm f/1.8
1,3sec, ISO640, f/1.8

Focusing

This is basically quite simple. Manual focus to infinity and leave it there. It may be a little bit tricky to find the infinity point, but try to focus on some bright star or radio tower in the horizon with magnified live view and you should be good to go. Take some test shots and double-check your focus. And remember to be careful so that you don’t bump your focus ring after you find the right spot! It’s something you don’t want to find out afterwards…

Shutter speed

Shutter speed varies with the situation. Sometimes when the northern lights move slowly, you may get away with 5sec exposure or even more, but when things speed up and you want to catch those rays, you want to stay in the 1-2sec range. It also depends on the lens you’re using. Wider lenses allow little longer shutter speeds, because the movement on the frame seems slower.

Good starting point for different focal lengths is:

5sec @14mm
2.5sec @20mm
1,3sec @35mm

If you are using a smaller sensor camera (APS-C, MFT), divide the shutter speed by your cameras crop factor.

ISO

ISO depends on camera. Modern cameras look fine at ISOs up to 3200 - 6400, but it’s best to take some test shots and decide what is the maximum usable ISO in your own opinion.

I would rather recommend to use larger ISO and shorter shutter speed than other way around. It’s easier to remove noise from your photos than it is fixing motion blurred northern lights.

Good starting point for ISO is 3200. (unless you’ve got an ISO invariant camera, but that’s a topic for another day)

Aperture

Aperture is simple. Go wide open. You want all possible light hitting your camera sensor. Depth of field is not usually an issue, if you don’t try to frame something close to you in to the same photo. The possible softness of your lens wide open is not that obvious in these type of photos.

If you frame something tighter with longer lens, then you may have to close down your aperture or do some focus stacking magic.

Summary

Northern lights are fascinating subject to photograph and it’s another good way to enjoy the great outdoors. Just remember these things to success:

Follow northern lights forecasts
Look for a dark location with views to northern horizon
Get to your location early so you have time setup your gear and think of compositions
Use your widest and fastest lens wide open, set shutter speed and ISO accordingly
Manual focus to infinity
Use tripod and remote shutter release

Check out my gallery for more photos!