Photographing the Aurora Borealis
Aurora and Sodium Vapor, Reykjavik 20 seconds f4, ISO 2500
I recently led two photo tours to Iceland to photograph the Northern Lights, and our groups each had the good fortune to experience several nights of clear skies and brilliant displays of aurora. The Aurora Borealis, as the Northern Lights are also known, occurs when electrically charged particles from the sun are carried by solar wind towards the Earth, and collide with gases in the upper atmosphere. Those gas particles—most commonly oxygen (green aurora) and nitrogen (pink aurora)—are “excited” by the collisions, and release photons of light. The Earth’s magnetic field deflects most of the solar particles, but the field is weakest at the poles. This is why the aurora is mainly seen near the polar regions. Solar activity peaks and falls on an eleven year cycle. The winter of 2012-2013 was the peak of the cycle, which was the best chance to see auroral activity for the next decade. In general, the chances of viewing the aurora are best at latitudes above 55 ° N, and between the months of October and March. Historically, October and March are the best months for aurora viewing. The frequency of clear skies is a big a factor in seeing the aurora as well, but broken cloud cover can add a lot of visual interest in aurora photographs. The aurora can appear at any time it is dark, but the best viewing times are typically 10 pm to 2 am.
Iceland lies between 64 and 66 ° N, and is ideally suited for viewing and photographing the aurora. Despite being so far north, it’s position on the gulf stream keeps the winters relatively mild compared to other good aurora viewing places like Scandinavia and Alaska. During my two tours in 2013, we had good viewing conditions and good sightings for 9 out of 17 nights, and really spectacular displays on three of those nights.
Warming Hut, 20 seconds f5.6 ISO 3200
Photographing the aurora is relatively straight forward once you understand the basics. The remainder of this article is intended to provide the basic information required for aurora photography.
Photographing the Aurora
Prepare for the cold
It’s obvious that you’ll be photographing in cold weather conditions and there are a few things you can do to protect yourself and your equipment from the cold. Dress in layers, making sure that you innermost layer is synthetic rather than cotton. Synthetic fibers wick moisture away from the body, keeping you warm and dry. Dress as if it will be colder than it really will be. Standing around for hours on end will make you feel much colder than if you were active, or only outside for a short while. Heavyweight merino wool and synthetic blend socks, insulated boots with wool or sheepskin liners, long underwear, lined pants, and wind pants or long underwear with ski pants are best. Make sure your neck is covered, and find just the right hat. Flip-top mittens with chemical hand warmers and possibly thin, form fitting glove liners are the best bet for your hands. If you’re going to Alaska, or somewhere truly cold, extreme cold weather clothing can be very expensive, but is essential.
As far as camera gear, you’ll want to keep your extra camera batteries close to your body in an inner pocket, as they will not last as long in the cold. You will want at least one extra battery. Remove any filters from your lenses, and be sure to use your lens hood, which will help minimize frost or condensation buildup on your lens.
Camera gear for aurora photography
Photographing the aurora tests the limits of our equipment, so this is a case where the best equipment possible really makes a difference in the quality of your images. Cameras with full frame sensors are ideal as are fast, ultra wide angle lenses. Cameras such as the Nikon D800 and Canon 5D Mark III are particularly well-suited to this work. If you are shooting with an APSc sensor camera, newer camera models that perform better at high ISOs are the next best option.
Fast, wide to ultra wide angle lenses in the 14-24mm range for full frame sensors are the most useful lenses, and those manufactured by Samyang under the brand names of Samyang, Bower, and Rokinon offer a great value for about 1/3 the price of the comparable Canon and Nikon lenses, and they suffer less from coma at wide apertures. It’s recommended to test these lenses thoroughly after purchase, as quality control is notoriously inconsistent. The Zeiss 21mm f2.8 is a great option, albeit a very expensive one. The best zoom lenses for this type of photography are the Canon 16-35 and Nikon 12-24. As previously mentioned, a lens hood or shade is helpful not only in preventing flare, but also for protecting the lens from frost and condensation.
A sturdy tripod is essential of course, and those with three leg sections are generally more stable than those with four or five. Insulated leg sections are easier to handle, especially on aluminum tripods. Ball heads are better suited for this work than traditional pan tilt heads because they can be adjusted quickly to track quickly changing aurora. Since exposures are generally thirty seconds or less, a remote release or intervalometer is helpful, but not required. The cables can freeze and break in extremely cold weather, so if the temperature is below zero degrees Fahrenheit, you’re better off without one. If you are working without a remote release of some sort, be sure to use the 2 second delay on the self timer to avoid camera movement when depressing the shutter button. The only other equipment you’ll need is an extra camera battery or two, and two flashlights: a dim or preferably red one for finding things in your camera bag or adjusting your camera, and a very bright flashlight to use as a focusing aid.
Well Head and Aurora, 30 seconds, f4, ISO 3200
Ambient Light and Aurora Photography
Ambient light from towns and cities will obscure all but the brightest aurora displays, so make sure you are well away from urban areas. That said, the distant glow from streetlights, the the last glow of a fading sunset on the horizon can add another element of color to your photographs. Sodium vapor streetlights reflecting off of low clouds is another possibility to add contrasting color to aurora photos. Lunar phase, and lunar elevation in the sky both have a profound impact on night photography in general, and aurora photography in particular. Photographing without any moonlight will mean primarily silhouetted foregrounds, and longer exposures at higher ISOs. Photographing under a full moon will mean much brighter foregrounds, especially if there is snow on the ground, shorter exposures at lower ISOs, and fainter aurora in your photographs.
You can photograph the aurora at all phases of the lunar cycle, and the results will vary fairly dramatically; it’s just a matter of what kind of images you are looking for. My own personal preference is to photograph between the first quarter and waxing gibbous phases as there is sufficient moonlight to illuminate the landscape without overpowering the aurora. The first quarter moon rises around noon, sets around midnight, and then rises about 45 minutes later each day until it is full. It rises about sunset and sets about sunrise. If you include interesting foreground elements, you may want to add light painting to your foreground, especially when there is little or no moonlight present.
Aurora and Sodium Vapor Clouds, 20 seconds f3.5, ISO 3200
Camera Settings and Exposure for Aurora Photography
Aurora photography pushes the limits of even today’s best DSLR cameras. Because of the low light levels, and the need to keep exposures relatively short due to the moving nature of the aurora, you’ll be photographing at the highest useable ISO of your camera, and the widest aperture that will yield sufficient sharpness and depth of field. Determining your highest useable ISO is simply a matter of testing your camera by making a series of low light exposures at increasing ISOs, and then scrutinizing the shadow areas of each exposure, preferably by making final size prints of the images. Determine which is the highest ISO that gives you image quality that is acceptable to your standards. For me, 1600 is the highest ISO I use for print quality images, and 6400 for web quality with my 5D Mark II. Similarly, you’ll want to test your lenses for coma at wide apertures by shooting starry skies at maximum aperture and then stopping down in 1/2 or 1/3 stop increments until you get to f5.6, and then looking at the resulting images at full magnification for signs of coma. A form of optical distortion, coma causes stars to appear as if they have “tails” like a comet, or sometimes like a bird in flight. It’s generally found near the edges of the frame in images shot at or near maximum aperture. The Canon and Nikon 24mm f1.4 lenses both suffer from fairly severe coma problems.
Exposures for aurora photography range from approximately 30 seconds at f2.8, ISO 6400 for faint to average aurora on a moonless night, to 4 seconds at f4, ISO 800 for bright coronal aurora on a full moon night. The intensity if the aurora itself can vary dramatically; sometimes it’s barely visible to the naked eye, but shows up nicely in photographs, and sometimes the aurora itself can be so bright as to illuminate the landscape itself. Determining exposure is accomplished by a combination of the RGB histogram and blinking highlight indicator. At a minimum, you should have a histogram that shows no shadow clipping—it may be a left biased histogram, but the histogram should not be touching the left edge of the graph. Images with more exposure will have cleaner shadows with less noise. Ideally, you should not have to lighten your image in post processing. Use the highlight indicator to make sure that you are not overexposing the aurora itself, or any highlights created by light painting. Use the LCD image preview primarily for confirming composition and focus.
Key camera settings
- Set Quality to RAW
- Use your camera’s Highest Useable ISO setting, hopefully between 1600 and 6400.
- Set White balance between 3700K- 4100K for Moonlight, 4000-5500 if there is no moon..
- Set your camera’s Long Exposure Noise Reduction to Auto (if available) or on.
- Enable your camera’s RGB histogram- primary exposure determinant in natural light.
- Enable the blinking Highlight indicator—make sure you do not clip the aurora.
- Set the LCD brightness to “auto” or reduce it manually to almost the lowest setting.
- Set Exposure Mode to Manual.
- Set focus to Manual.
- Turn off IS/VR lens functions
- Use flashlight assisted magnified Live View, or conservative, well executed hyperfocal distance for focusing.
Download the pdf: Basic Camera Settings for Milky Way and Aurora Photography for more information and a complete list of camera settings.
Taking a Moment, 10 seconds, f4 ISO 2500
As with any type of photography, you’ll get better results with experience and practice. It’s very helpful to have a basic understanding of night photography, and to be completely familiar with your equipment before departing for the North. Simply working in the cold and darkness complicates photography exponentially, so do your homework, and be prepared. Don’t expect to get perfect results on your first attempt. Photographing the Northern Lights can be like photographing a close friend or family member’s wedding: you’re so focused on the task at hand that before you know it, the event is over and you’ve completely missed out on the experience! Make sure that you take some time to simply step back, look up, and enjoy the magnificence of this special phenomenon.