DWVPhotoworks' Guide to Northern Lights
Aurora borealis, or the Northern Lights, often synonymous with spectacles and phenomena are visual displays, as elusive as they are breath-taking.
I have been shooting them for several years now and I figured that I would share some of the things I have learned along the way. Some of it has been through endless reading and studying, most of it has been through trial and error. Hopefully, I am able to help bridge those gaps and make things a little easier for you.
Preparation:
This is the most important part for getting quality aurora photos and also the most frustrating. The biggest determining factor for getting a good shot of the northern lights is whether or not they are active. Don't get me wrong! You can drive out of town, set up, and get lucky. I have done it before, but your chances are usually fairly slim.
You will want to select any variety of aurora alerts, which you can find readily available online through a myriad of different services; some of them are paid, some of them are free. I use Aurora Alerts by SoftServeNews.com. I don't subscribe to customized alerts, I just follow their official Twitter account, @Aurora_Alerts. They will tweet any time that there is predicted aurora activity.
Now that you know what to look out for, the next step is understanding it. You will need to know the "Kp Number" relative for your viewing area. This is a strange concept but I will try to explain it for you:
@Aurora_Alerts tweet showing that in 45 minutes, the aurora are predicted to be active at level 4 Kp.
The higher the Kp number, the farther south the aurora will be visible. By using the satellite image below, you can roughly tell that the Kp required for southern Saskatchewan aurora-viewing is roughly about 3-4 Kp.
Your location on the map will indicate which Kp level is appropriate for your area. The higher the Kp level, the further south the aurora will be visible.
The next thing to consider is the Ovation map. As with finding the appropriate Kp value for your area, seeing where the current aurora plane is in relation to your area is important. This one might take some time to learn through your own experiences.
I notice that for south Saskatchewan, the ideal time is around 22:00-02:00 CST where the aurora oval is closer and gives you a greater chance of seeing activity. To further this example, around the same time in Iceland (local time) is when the oval is over that area of the earth.
Luckily, the Ovation map has been developed and you can get a very decent depiction of the current position of the ring. In this example, the aurora ring is in a decent position for my area so there would be a good chance of seeing something.
Once you know there are aurora predicted and that the aurora ring is in position, it's almost time to hit the road. Hopefully you already packed your gear so you can leave quickly. There is usually only about 30-60 minutes once a prediction is made so you need to be quick.
There is one last thing to check: the sky. Hopefully, it is clear or has minimal cloud. If it is overcast, then you are not going to have a good time. If it is clear, or perhaps even partly cloudy, then hit the road.
Equipment:
- Camera with manual settings (preferably a DSLR)
- Sturdy tripod
Some of the following things, while not considered fundamental, can be very beneficial to getting a better image:
- Intervalometer or cable release (if need be, 2 second delay works in a pinch)
- Star-tracking app
- Headlamp/flashlight (preferably with a "red" setting)
- Wide-angle lens (preferably with focus indicator window)
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Location shopping:
Ideally, you already have a location that is a combination of the following elements:
- Far enough outside of urban areas that it is as dark as possible. I use a service called Dark Sky Finder: http://www.jshine.net/astronomy/dark_sky/
- Contains foreground elements. Your images will have a much better result when they contain some compositional elements and aren't just photos to prove that the aurora exist.
- Easy to get to. My default location is a quick 15 minutes from my home, 20 if I need to get gas.
Dark Sky FInder | I usually find that if you can't get all the way into the shady grey area, the blue, or even sometimes green will be dark enough for great photos.
If you don't have a location already in mind, you will want to be less picky with your location and just try to work with what you can see in your area, quickly. I recommend shooting from an area of lower elevation, such as a valley. If there are any other lights, cars, or highways nearby, they will be masked by the change in elevation and will not be a distraction on your image.
Setting up:
Setting up is fairly straight-forward. I have included my recommended go-to settings below for aurora and astro-photography as a whole.
20s @ 11mm f/2.8 ISO 800
You will want to make sure to set up on a level area, perhaps out of the wind, or somewhere comfortable. I have ranged from being in the comfort of a sleeping bag while reclining in a lawn chair, to being buried waist-deep in snow while on thin ice. While I do not highly recommend doing anything on thin ice, I do recommend exercising caution when exploring. That being said, some of the best shots come from getting right out of your comfort zone.
As I mentioned above about the importance of foreground elements, there are many things that you can find. My personal favorite is water. The beauty with water is the reflection and how it behaves through long exposures. If you don't have any water near you, or it's winter, then look around your area for old buildings, fences, tractors, etc. Opportunities are endless, you just need to find them and frame them facing north.
I am using my 11-16 mm f/2.8 in this example, so I am opening up the aperture as much as I can to gather as much light, as quickly as possible, without being too noisy. As I mentioned, I usually start here but depending on the conditions, you might need more light, or even less in some situations.
Northern lights simple a single streak across the sky. Note the light foreground from the nearly full moon and the shadows cast by the fence.
If you need more light, there are some things you can do:
Increase ISO: Increasing ISO will increase exposure but it will also introduce more noise. You need to know your camera and how it performs in low light situations. I know that for my 70D, I start to draw the line with maximum ISO topping out at about 3200. Any higher and you just end up losing too much detail when reducing the noise in post.
Wider aperture: This value is often defined by the limits of your hardware, however, if you happen to be able to open wider than 2.8, do it! Not only are you letting in more light, but you are not introducing any more noise as the ISO is the same. This is the main reason why fast lenses are so expensive!
Exposure time: Another way to increase the amount of light in your exposure is to lengthen the amount of time your shutter is exposed for. As with increasing your aperture, exposing longer doesn't necessarily introduce more noise but there is something else you should be aware of.
Free some space and store spare memory cards inside your body/lens caps.
Based on the focal length (lens size: 18-55mm, 11-16mm, etc.) of your lens, there is a point that stars will start to visibly streak. With my aurora shots, I'm usually almost always using the 11mm focal length. Based on the "500 Rule", take 500 and divide it by your focal length and that will be the maximum time (in seconds) that you can expose before stars will begin to trail. I wish it was that simple, but it isn't. As I mentioned, I'm using a 70D, which is a 1.6 crop sensor as opposed to full-frame. So previously where the equation was 500/11mm, it now becomes 500/(11mm x 1.6). The magic number here is 28.4s.
Additional tips:
Focusing can be tricky depending on the hardware you plan on using. I made the choice to go and buy a wide-angle lens mainly for landscape photography and astro-photography. I decided to get the Tokina 11-16mm f/2.8 for a few reasons. It gets really wide, and it's fast at 2.8 all the way throughout the zoom range. It is also really easy to focus to infinity on it; simply turn the focus ring all the way to the right.
Tokina 11-16mm f/2.8 | Note the focus window and infinity symbol.
*If your lens doesn't have a window to see the focus indicators, it might not be as easy. A method I use is to use "Live View" and zoom in as far as you can (on the screen) and adjust your focus manually. Try cranking your ISO almost as high as it can go. It doesn't need to be clear, you just need to see enough to focus.
When out hunting for aurora, you need as much darkness as possible. Once you are in darkness for about 10 minutes, your eyes adjust to the conditions and you can see much better. It can be difficult keeping your eyes adjusted for low-light when you have other light sources around such as the dashboard or headlights in your car, high-powered flashlights, headlamps, or even the LCD on your camera.
I always forget to adjust the LCD brightness, myself. When I go out shooting aurora, I find my eyes settle down, then I take a photo and the screen is so bright that it takes a few minutes to adjust back down. Turning the screen right down low, or even disabling completely, will help with keeping your eyes adjusted to the environment.
Petzel TIKKA PLUS 2 with "red" setting.
Another tip is to use a headlamp with a "red" setting. Something about the red wavelength makes it less aggressive on your eyes yet really helps you see things in the dark. Always turn it off when your shutter is open and turn on as needed and your eyes will take less time to re-adjust to the darkness.
I won't go too far into detail with the next item. I find that it is fairly straight-forward and equally as essential: toilet paper.
It may seem overwhelming when you consider all of the things that I deem necessary before heading out on an aurora adventure. I have chipped away over the years to come up with a routine that seems to yield positive results and is also very rewarding.
There are many times when the alerts come at the most inopportune moment and it takes a lot of effort to get up and go. Other times, it can just be purely coincidental and painless. The key to harnessing these opportunities is to be prepared. The less things that you need to do to be ready when the aurora hit, the better.
Every now and then, there are predictions for solar storms. These are the activities that cause aurora activity and are usually predicted anywhere from 6-48 hours ahead of time. The solar storm watch will usually indicate what levels are expected, such as Kp 4, Kp 7, etc., when the storm is expected, and how long the watch lasts for.
Usually solar storm watches are in effect over several days and often have a peak or climax where the aurora activity is at its maximum. Once you get into the higher Kp levels (Kp 5+), that is when you start to see very erratic spires and many different colors, all across the sky.
G1-level magnetic storm outside Regina, Saskatchewan | February 2014
