How to Chase and Shoot the Aurora

From the Editor:  Award-winning landscape and nature photographer Carl Johnson has been living in Alaska for almost 20 years and is an expert on shooting auroras.  On Friday, August 17th, at 2 PM EDT, he will present a NANPA Webinar, “Chasing & Photographing the Aurora Borealis.” This webinar covers the science behind the aurora, the tools available to predict and plan for it (including websites and apps that provide real-time and forecasting information), tips on when and where to photograph it, and what gear and techniques to use. For more information or to sign up, click here.

 

by Carl Johnson

www.arcticlight-ak.com

Summer days are long in Alaska, whose nickname after all is the “Land of the Midnight Sun.” For aurora chasers, this can be frustrating. As we watch our friends from the northern states of the Lower 48 post summer images of the aurora borealis, we ignore our automated aurora alerts and wait for the darker nights of Autumn.  Understanding the timing and locations where the aurora can be viewed is 90% of the work in photographing it. Once you do get a handle on that, and the technical aspects of photographing the aurora, then you, too, can join the long list of nature photographers for whom this has become an obsession.

When to Go

Certain times of the year are better for chasing the aurora; you can’t effectively go aurora chasing when it is not dark. (You could go in the daylight if you are a sucker for quixotic pursuits.) I know, it seems crazy to mention, but a lot of people ask me when the best time of year is to see the aurora, or they ask if it has to be cold for the aurora to come out. My answer is that the best time is when it is dark and in Alaska, that more likely than not means cold. Sure, it starts getting dark enough to see them in August (I have photographed it near Anchorage as early as August 2), and you can still see them in the first week of May (the latest I have shot is May 8), but most of the time during those months in between, it is cold outside.

The aurora is most active around the fall and spring equinoxes. Scientists know that there is a breach in the earth’s magnetic field during that time that allows more energy to come through and create active aurora borealis displays. The most active month is March, followed by September and October. While these are the best times for viewing and photographing the aurora, although I have photographed some good displays in August, November, January, and February.

Another consideration is the phase of the moon. I rely on the U.S. Naval Observatory website as well as The Photographer’s Ephemeris (desktop version and mobile app) to check the phase of the moon and when it will rise and set at a particular location. Unless you are planning on using silhouetted trees as your foreground, a new moon is not the best time to capture the aurora. A little bit of moonlight will bring some detail to the landscape and make your photo more interesting. With a dim aurora, a full moon will provide too much light and overpower the aurora (but with a strong aurora, it doesn’t matter).

Preparation

Unless you live north of the Arctic Circle, you can’t just head out on any clear night to photograph the aurora borealis.

There are certain conditions that produce auroras strong enough to be seen farther south; and they are not always present. So, you need to know how to interpret the space weather as well as the Earth weather, and get a read on current conditions.

First, you can’t see the aurora if it’s cloudy where you live. In Alaska, the best source for weather information is the NOAA Alaska Region website. You can get detailed regional forecasts and examine real-time satellite imagery of cloud cover in your area, including six-hour loops. That way, if it is cloudy where you are, you can use satellite imagery to look for holes in the clouds. Your best bet for nighttime imagery is to go with the “Thermal IR” or “Infrared” images. If you want to check for clear skies as sunset and dusk approach, an excellent resource is the FAA Aviation Weather Cameras website. It provides live snapshots of the skies in key flying areas of Alaska – these cameras are all over the place! In most cases, they provide views in all four directions, and at the least, three directions. Look to your local agencies to see what they have to help you find clear skies.

Second, you need to know if the space conditions are going to produce an aurora in your area. The first indicator is the strength of the forecast for that night. The best forecast service I have seen is from the NOAA Space Weather Prediction Center. You can subscribe to a variety of email alerts, but I recommend the 3-day forecast. You can also view the 3-day forecast for geomagnetic activity directly on the NOAA Space Weather Prediction Center website. It is updated at least twice a day and has been quite accurate since I started using it. NOAA also has a 30-minute forecast. Other short term forecasts include Soft Serve News. Look for what “KP Index” or “Planetary K-index” is predicted. The higher the number, the further south the aurora will reach, and the more active the aurora will be. For example, a KP3 aurora can reach overhead Anchorage, while a KP7 aurora can reach overhead Seattle.

Your best bet for obtaining and understanding the data necessary to determine if there is going to be an aurora is to visit Spaceweather.com and SolarHam. Look for discussions on when a CME (Coronal Mass Ejection) is expected to hit the Earth’s magnetosphere, as well as the speed of the Solar wind (look for increasing winds, better than 500 km/sec) and a southerly Bz in the Interplanetary Magnetic Field. The higher that Bz (south) number, the better. For the St. Patrick’s Day 2015 display, which produced a Kp 8 storm, it was over 20. You can also see the current and anticipated KP Index. Additionally, you can sign up for text alerts on Spaceweather for a nominal monthly fee ($5).

Third, if you are an apps user, there are a ton of aurora apps out there. The one that I find most useful, and tracks most consistently with the websites upon which I rely, is the My Aurora Forecast Pro app. It provides two different views of maps for best current locations, provides short-term and long-term forecasts, viewing and cloud cover probabilities, and more. It is not a free app, but it is not expensive, either. If you are a regular aurora chaser, it is worth the nominal cost.

Finally, in addition to the real time data on Spaceweather and NOAA POES Auroral Activity, sometimes it’s nice just to be able to look and see. There are two aurora cams that are worth bookmarking on your computer and smartphone. For Alaska, you can’t go wrong with Ronn Murray’s Alaska Aurora Cam, housed at Sirius Sled Dogs in Fairbanks. For Canada (even though I know of many Alaskans who follow it), keep an eye on the AuroraMAX aurora cam in Yellowknife. For Facebook reports, join the Aurora Lovers and Aurora Borealis Notifications pages. I also follow the @AuroraMAX and @AuroraNotify Twitter feeds, which provide real time updates.

Ready for the Road

Most people who are experienced and prepared drivers in Alaska have a winter survival kit in their car. I have one of those. But I also have an extra set of gear in the back of my car to provide some additional comfort in my aurora hunting. I have a bag that contains a MSR Whisper-Lite stove, a MSR bottle of white gas fuel, a Ziploc with snack bars, instant Starbucks coffee, hot chocolate, and plastic eating utensils. There is a bag of Sailor Boy Pilot Bread and a container of creamy peanut butter to go with it. I also have a small cook kit and a kettle for boiling water, and a travel mug for drinking hot liquids. This bag, along with a few camping chairs and a -20 F sleeping bag, stay in my car at all times.

In my office, I keep a camera bag fully-loaded and ready to go for running out after the northern lights. Having the gear ready eliminates the frustration and stress of running around packing while panicking that you’ll miss the aurora. And, I avoid forgetting something important in the chaos of a quick departure.

My bag contains my Nikon D850 and three lenses: Nikkor 14-24 f/2.8 AFS, Nikkor 24-70 f/2.8 AFS and the Nikkor 70-200 f/2.8 AFS VR. I also stock an assortment of XQD and SD cards, spare batters, lens cloths, Lee GND filters (in case there is a great aurora display over some artificial lighting, like the city or a cabin, or to balance exposure involving a reflection), battery charger, and AC inverter to plug into my car “cigarette lighter” outlet. Sitting next to it is a one-gallon jug of water for making coffee or hot chocolate.

Before heading out, you need to make sure you are dressed for the long haul., You will not see me wearing cotton! It has to be either synthetic, or wool, or fur. Cotton, when wet, takes longer to dry and does not retain heat very well. For my head, I take a seal/beaver/otter hat handcrafted by an Inupiat artist, a thin hood layer, and a mask. I wear two layers under my jacket, and a pair of thermals under a pair of snow pants. If it’s really cold outside, I trim back the upper layers and instead wear my traditional Inupiat Eskimo parka with wolf and wolverine ruff. For my hands, I prefer a thin liner glove underneath a set of fingerless gloves with a mitten flap. On my feet, a pair of wool socks and a set of Baffin polar industrial boots. Sometimes I wear moose hide Steger Mukluks or Baffin boots, depending on how cold it is or how much snow depth there is, or if I anticipate possibly having to step through shallow water. (One of the advantages of shooting the aurora in Southcentral Alaska is that, even in the coldest months, you can find open water.)

Where to Go

The conditions are right and you have the gear ready. Now, you need to decide where to go. What makes a good location? If you don’t want city lights in your photo, get out of the city and out to a location with an open view of the sky to the north. That is not to say it is impossible to photograph the aurora within a city. I have four locations in Anchorage, a city with a population of over 300,000, where I know I can go and successfully photograph the aurora.

While sometimes the aurora can be awesome enough to stand on its own, a flat foreground generally leads to a flat photo. Try to find a place with some foreground elements to add interest—look for a location with water, trees, distinctive mountains, maybe some sort of structure (like an old bridge or building).

Taking the Photos

At first, it may seem like you’re adjusting a lot of settings but, once you get familiar with capturing the aurora, they’ll become second nature.

Lens selection and focus. I prefer a lens no slower than f/2.8 and as wide as 14mm. Shooting at f/4.0 or slower will often produce too long an exposure to get the brilliance you need for some of the less vibrant, but still lovely, displays. The longer exposures required by an f/4 lens will create undesired star trails at anything longer than 30 seconds, sometimes even 15 seconds, depending on the focal length. Having that wide focal length of 14mm is key to capturing phenomenon that encompass the whole sky. On a typical night, I will start the evening with my 24-70mm lens, then shift to the 14-24mm as the aurora gets more active and covers more sky.

Disable your automatic focus and use manual focus; then set the focus point near infinity. If you place your focus point right at infinity, you will get slightly-out of focus images. Use your initial waiting time to take several test photos. Move your focus a little bit in each direction and check the focus by zooming in on the stars on your LCD display until you find the right setting. If the moon is out and bright, I will actually turn on the auto focus, focus on the moon, and then switch back to manual focus, locking in that setting. You can also use Live View mode to zoom in on a focus point and manually focus on that. Once you have your focus set, strap a thin piece of Gaffers tape across the focus ring to ensure it does not move the rest of the evening.

Filters. Remove all filters from your lens. We all like to put UV filters on our lenses to protect them from damage. But a screw-on filter of any kind will create a distortion, represented by concentric circles, in dead center of your image. Somehow, the light of the aurora bounces back and forth between the lens elements and the filter during long exposures to create this undesirable effect. However, I have used graduated neutral density filters (square filters in a bracket attached to the lens) to darken a brightly lit foreground or to balance the exposure of the aurora with its reflection on a water surface.

Camera functioning. The key to keeping your camera working in the cold is batteries. I always take at least three spare batteries with me when venturing out into the cold. I keep them in a quart-sized Ziploc™ bag, tucked inside the layers I wear to keep myself warm. As your battery power starts to wane, simply replace the cold battery with a warm one. One thing I will sometimes do if I have my vehicle nearby is run my camera directly on A/C power, running a power cable through an A/C inverter that is plugged into my car’s “cigarette lighter” plug.

Be mindful of condensation. At extreme colds, your breath will fog up and frost the back of your camera, including the viewfinder and LCD display. Hold your breath when composing. And be careful when you take your gear from a warm to a cold place (and vice versa)—give it time to adjust. To prevent fogging and frosting of your lenses, either keep your camera and lens together in a camera bag when bringing them back into your vehicle (and keep the bag away from a heat source), or simply remove your battery and leave everything outside. If leaving your camera outside for extended periods of time in the cold, you may also want to cover your lens to prevent frost buildup.

Settings. With your aperture set at f/2.8 (or whatever is the widest opening on your lens), set your exposure mode to manual. Then, set your exposure at 8 seconds and ISO at 1600. This is a good starting point, but, depending on the intensity of the aurora and the brightness of the night sky (if the moon is out), you may need to adjust your shutter speed and/or adjust your ISO. My most common settings are ISO 1600 at 6-10 seconds, but I have used ISO 400 at 2 seconds for a really bright aurora and ISO 3200 at 30 seconds for a really dim one. If your exposure need to be longer than 30 seconds, use a higher ISO instead. If your camera has it, enable High ISO Noise Reduction. You may also want to enable Long Exposure Noise Reduction, but remember that you’ll have to wait longer between exposures for it to do its job. Set your white balance to Auto. Finally, make sure you are shooting in RAW.

Tripod. Of course, the basic rules of long-term image stability sill hold: tripod, cable release, and using the mirror lock up feature. One of the more challenging aspects of composition for an aurora shot is ensuring that your horizon is level. This can be accomplished by using (a) a bubble level for your hot shoe, or (b) using a digital level function within the camera (if you are lucky enough to have one; the newer Nikon cameras do).

Now You Wait

Now that you have suited up, geared up, checked the latest data on geomagnetic activity and found a good location with clear skies, it’s . . . time to wait . . . and be patient . . . and wait some more. On a good activity night, you won’t have long to wait, as the aurora can hit as early as dusk. If it’s good and looks like it’s going to remain bright and busy all night, don’t stay in one location! Move to somewhere else and capture other images. I like to diversify my shooting locations so that all of my aurora borealis photos don’t look the same. Diversity is one way to make your aurora images stand out from others. Just like any other landscape photography situation, it’s important to vary compositions, lens focal length, and orientation (horizontal or vertical). If you feel like you have captured “the shot” for the night, keep shooting anyway! Try a few new techniques and compositions. When I can, I like to set up and capture images for creating a time lapse movie. I take along a second tripod and camera (or even a rail system) to capture the time lapse so I won’t have to worry about missing a good still capture.

A short night for me is typically about three hours. Several nights, when the display was particularly spectacular, I was out for eight hours or more—and could have stayed out longer! On those occasions, I decided to call it a night between 4:30 and 6:00 a.m., feeling I had captured a lot of really good images and could go to bed satisfied. Coming back with some great aurora borealis images is exciting, but it can’t begin to capture the thrill of just being out there, witnessing this amazing phenomenon.

 

Carl Johnson is an award-winning landscape and nature photographer based in Anchorage, Alaska. In 1999, he moved to Alaska and, in 2015 founded Arctic Light Gallery & Excursions. He has been Artist-in-Residence at three national parks, has received grants and fellowships for his work, and his photography has been received numerous awards.  His first book, Where Water is Gold: Life and Livelihood in Alaska’s Bristol Bay, was awarded a Silver Medal in the 2016 Nautilus Book Awards and a Gold Medal in the 2017 Independent Publisher Book Awards.