The night sky is an incredibly rewarding subject for photos; the aurora is even more so, since it captures both the stars and the elusive and breathtaking phenomenon that is the northern (or southern) lights.
One big difference between shooting the night sky and shooting the aurora is that the northern lights are an incredibly dynamic subject. Sure, the stars move over time, and sometimes the aurora is quiet enough that you can only barely see its movement; in this case, similar settings to a standard night sky photo will get you quite a nicely exposed shot. However, if the aurora is flickering and dancing across the sky, sometimes in the matter of seconds, you’ll have to be able to adjust your settings on the fly to ensure your photo doesn’t just turn into a blob of brilliant green.
Hopefully these tips will help you feel a bit more confident with anything the aurora throws at you and show you how to capture images that make you feel like you’re back under the night sky, gawking at the crazy show above you.
Preparation & Choosing Your Gear
The more preparation you do prior to heading out into the (often cold) night, the better off you will be. I’ve compiled a full list of preparations you can do — from knowing the space weather forecast, to having an up-to-date weather forecast, to choosing the compositions you’ll use — on my previous post Preparing for a Northern Lights Shoot.
As mentioned in my preparations blog post, you will want to shoot with a camera with manual mode that allows you to adjust shutter speed, aperture, and ISO. All dSLRs and mirrorless systems will have this option.
In addition, you’ll want to have your widest possible lens so you can have a longer shutter speed and include as much of the sky as possible. If it’s very cold outside, you’ll want to mount it on the camera prior to the shoot so you’re not fumbling with it with gloved hands.
Unlike you have for subjects like the Milky Way, there are no magic settings that will give you a well-exposed shot. That’s because the aurora is an amorphous subject that can be so dull that its colour can’t be seen with the naked eye or so bright that it makes the snow underneath it look like it’s radioactive.
You should generally keep your aperture as wide open as possible — that is, one of the smallest f numbers — when shooting at night. For instance, if your lens is f4, shoot at f4. If your lens is f2.8, shoot at f2.8.
This goes against what you’re often taught about landscape photography, which is that you need to keep the aperture narrow to ensure a deep depth of field. While this is useful during the day, a wide open aperture allows your camera to gather more light at night without having to increase the ISO, which increases noise. It will also help the stars behind the aurora appear brighter.
Plus, you’ll often find that the shallow depth of field is not terribly noticeable since you are focusing on infinity, and most of your foreground will often be far enough away that your camera treats it as infinity as well. (On most wide angle lenses, anything beyond 3 meters away will be treated as “infinity.”)
Your shutter speed will vary immensely over the course of the night; as an example, my shutter speeds have varied between around 2s during the biggest storms to 30s for the slow-moving, less colourful shows. 15-20s is a good starting point, but as we’ll discuss below, it’s important to adjust this based on what you’re seeing.
Your ISO will usually vary between 800-3200. Because a higher ISO will add more noise to your photo, you’ll want to use as low an ISO as you can (although sometimes the show is faint enough that dropping the ISO too far will result in a very underexposed image). 1600 (the middle of the range) is a good starting point.
In short, a good starting point is around f4, ISO1600, and 15s. If this is too dark, lengthen your shutter speed or increase your ISO. If this is too bright or gets rid of the definition you can see with your eyes, decrease your shutter speed.
Then…Changing Your Settings
As I’ve mentioned before, the aurora is a dynamic subject that is constantly moving — and more importantly, constantly changing its brightness. While some nights may have fairly stable conditions that allow you to shoot with the exact same settings throughout the night, they will be the exception, not the rule. You’ll need to be ready to change your settings, and you’ll need to do so quickly.
If the lights start to move quickly (i.e. you are starting to see waves all across the sky), you should decrease your shutter speed. The reason you want to change your shutter speed and not any other setting is to do with the movement you are capturing. If the lights move too much across the sky during your exposure, you will end up with a photo with an entire sky of green that has little to no definition. While green is a nice colour, it’s much better to have textures and signs of movement in your photo, since this is what makes the northern lights as spectacular as they are.
If you decide you need to shorten your shutter speed to get more definition in the aurora, you will need to increase your ISO to maintain the same exposure. The reason you have to adjust the ISO rather than the aperture is because your aperture is likely already wide open, so you cannot adjust it to let in any more light.
Alternatively, if you are shooting a bright show that suddenly dims, you will need to choose whether you want to lengthen your shutter speed or increase your ISO to brighten your image. Lengthening the shutter speed will help you capture green in more areas of the sky as the aurora moves, but you will lose some definition. Increasing the ISO will add noise, so try to avoid going over ISO 6400 if at all possible. Noise performance has improved greatly on newer models of cameras, but beyond 6400 you’ll start to see noticeable noise regardless of your camera.
Getting the scene in focus is by far the most frustrating part of shooting at night. Your camera focuses best when there is contrast at the focal point; at night, you generally don’t have any contrast around you because everything is just varying levels of black. Therefore, if you try to use autofocus, you’ll generally find that the camera will try to focus, fail, and leave you with a scene that is even more out of focus than when you started.
There are three common ways to focus at night:
- Use a flashlight to light up an area enough that your camera can focus. If you are shooting with a wide-angle lens, your camera will treat anything further away than ~3m as “infinity.” This means that focusing ~4m away is the same as focusing on the mountains in the distance or even the stars. Practically, this means that you can shine a bright flashlight on a nearby tree and focus on it rather than struggling to focus on foreground elements in the distance. Aim your camera at the tree, press the shutter down halfway, and then switch to manual focus. Just remember that if you zoom in or out (or knock your focal ring), you’ll have to do this again!
- Use live view to zoom in on details and manually focus on them. Sometimes your focus will still seem a bit off, even when using method #1 above. That’s where live view comes in handy. While live view is not great for general use at night, it can really help with determining if you are truly in focus. To do this, turn on live view and locate the magnifying glass buttons on the back of your camera (you won’t use the zoom ring on your lens as you’re just working with digital zoom here). Magnify the scene until you find something clear enough to see (which could be a tree lit up by your flashlight as in method #1). Then, turn the focal ring on your lens until your foreground element is crisp.
- Know where infinity is on your lens and set it manually. All lenses are different and their ‘infinity point’ may be smack on the infinity label on your lens, or it could be slightly off. I recommend testing during daylight by auto-focusing on items in the distance, then checking your lens to see the exact distance it has focused on (which you can see on a display similar to the one pictured above).
Once you’ve got your focus sorted using any of these methods, it’s crucial to make sure you choose manual focus on your lens. Otherwise, the next time you try to take a shot, your camera will try to autofocus and you’ll have to go through this whole rigmarole all over again.
Things to Avoid
There are two things that can cause subtle issues in your aurora photos that you may not notice until you get home: image stabilisation and filters.
When you are using a tripod, you don’t need image stabilisation as your camera is already on a stable surface. The addition of image stabilisation can actually make your photo slightly blurry as the camera tries to stabilise an already steady shot.
As mentioned in my preparations post, filters can cause some very interesting artefacts in aurora photos, commonly seen as a series of concentric circles created from reflections of aurora light within the filter. These are unremovable (unless you’re willing to sink hours into each photo), so it’s best to just remove all filters and leave them in your bag for the night.
Now that you know how to plan and execute a northern lights shoot, remember to not spend the entire time looking through the viewfinder. Sometimes it’s best just to learn back and stare up at the sky in awe rather than fiddling with settings and missing what is happening above you. You won’t regret that uninterrupted time at all, even if it means you have a few less photos to show for it.
Finally, I can’t guarantee that, even if you follow all of these instructions to a T, that you’ll get perfect photos. Aurora photography is not that exact of a science. Hopefully this will give you a good starting point so you can adjust accordingly and get some fantastic photos to remember your time in the north seeing one of nature’s most stunning phenomenons.
Is there anything I didn’t cover in this post series? Comment below or get in contact with me here.