What tips and advice do you have for photographing the Aurora Borealis?

Question

A friend has been kind enough to lend me a DSLR for a few months. It's my first foray into DSLR photography, or indeed any kind of photography beyond simply aiming my Canon IXUS at something and clicking the button.

Over the last few weeks, I've been busy studying, practising and trying to learn as much as possible ahead of a planned trip to Norway where I hope to see, and get some photos of, the Aurora Borealis.

I currently have:

• Canon Rebel Xsi (450D)
• Canon 50mm f/1.4 L
• Canon 18-55m kit lens
• Aluminium full height tripod with ball head
• Cable release
• Spare battery & memory cards

I'm prepared to spend the night wrapped up outdoors, in the hope that they will make an appearance. I'd like some advice on how to get the most out of this kit for the trip:

• How should I go about setting up to get pics of the Aurora?

• How might I achieve optimum focus?

• From what I've read, I'll need to use the tripod and cable release, with IS turned off, on continuous shooting mode with long exposure times. But I'd like some more specific tips in terms of which aperture and ISO settings might work best?

• Should I use one of the lenses above, or would it be worthwhile renting a better, wide angle lens; if so, which would you recommend?

Answer 1

I've never attempted to photograph the Aurora Borealis myself however the following advice applies to most celestial photography:

You will want the fastest (biggest aperture) lens you can get your hands on. The 50 f/1.4 is ideal, though the focal length is quite long for this sort of thing. It's good because it will let in about 5-6 times as much light as the kit lens! Fast wide lenses are a rarity for crop camera bodies such as the 450D. If you need to go wide you might get away with a Sigma 20 f/1.8, the other alternatives are not cheap: the Canon 16-35 f/2.8L would be better than your kit lens, but I'd personally go for the 24 f/1.4L even though it's not as wide.

• In terms of focussing, for the lights themselves you'll probably want the lens set to infinity (i.e. as far as the focus ring will go) or occasionally just short of infinity. Given that the lights are very far away (i.e. the upper atmosphere) your depth of field at this focussing distance will be huge. If you want to get some foreground in for scale / composition, then obviously you need to set focus for that distance from what I can tell the Aurora are kind of fuzzy anyway to it wont matter too much if you have to focus closer. AF probably wont work in that sort of light so you focus by trial and error or maybe use live view to focus.

• Shutter speed is a compromise between letting more light in to minimise noise, and avoiding motion in the images. I don't know how fast the Aurora move but this will probably limit your shutter speed. Noise can also increase with shutter time due to the sensor heating up however this might not be a problem where you're going! Multiple short exposures are generally better than one long one.

• To reduce noise you need to get as much light down the lens as possible, and then set the ISO as high as possible (without overexposing). This sounds counter intuitive so I'll explain a bit more. High ISOs don't cause noise and actually exist to reduce noise. Noise comes from the sensor electronics, but also from the random nature of light itself. So it's not high ISOs that cause noise, it's low levels of light. The confusion originates from the fact that using a high ISO in auto mode will allow a faster shutter speed and result in more noise, however the noise is a result of a fast shutter letting in less light. If you're already letting in as much light as possible, then lowering the ISO will reduce the amplification on the sensor, and when the values are read out they will be lower and thus the readout noise will be higher in proportion. When you correct the exposure in post you amplify this readout noise. When you use a high ISO, the analogue signal is amplified before readout occurs so you don't end up amplifying the readout noise. If you still need convincing, check out this example of an underexposed ISO100 is far noisier than a correctly exposed ISO1600 shot. For the settings used, increasing the ISO, even to 1600, decreased the noise: http://www.mattgrum.com/ISOcomparison/ISO_100_vs_ISO_1600.jpg

Generally when working at night stacking is the way to go. This means shooting many shorter exposures and then combining them on your PC to produce a single image. There are many pieces of software that will do this for you, Deep Sky Stacker is one of the best. The software is designed to cope with the movement of the stars, it may be able to cope with the aurora moving as well, or you might get some ghosting.

Other things to bear in mind are that cold dramatically reduces battery life, so keep one battery in an inside pocket close to your body and swap them often. This probably wont affect you but if you're shooting exposures around 1/2s you should use the mirror lockup function to avoid the mirror slap causing vibrations which can show up in the image.

I would also recommend searching flickr for photos of the Aurora, most of the images will have the EXIF information still attached so you can see what camera settings / lenses other people are using.

Good luck!

Answer 2

Here is the exif info.

I think is quite light, but I'm working on it :). If the aurora is strong than is not quite so difficult, probably a 5-10 seconds exposure will do it. I do my photos with 25-30'.

Answer 3

From my own experience, I can make the following recommendations.

• You should practice handling your tripod and camera in dark conditions. This will help you to set up the camera and tripod quickly or to change camera settings when your hands are slowly going numb in the ice cold conditions. The problem here is that when handeling the camera, you need to use gloves that are more flexible than the standard gloves that you normally would use in this sort of weather but your tripod will be at deep freeze temperature.

• You need to experiment with your camera what the best setting are for long exposure. I disagree a bit with Matt's answer on this point. A higher ISO setting means that you have higher analogue amplification of the signal and that brings with it more amplifier noise. The camera has different noise suppresion settings and you need to know what works best. E.g. I took my pictures with an ISO 400 setting and used exposure times ranging from about 10 seconds to about 40 seconds. Then some cameras also have a noise reducion for long exposure, this doesn't affect image quality unlike the high ISO noise suppression. You can also use the image stacking software that Matt mentioned above or do this yourself by e.g. exposing 4 times 10 seconds instead of 40 seconds and then combing the 4 pictures digitally by throwing out outliers of every small area in each of the 4 pictures and replacing them by the avergage of the other 3. You then add up the 4 pictures.

• For focussing I put the camera on manual focus and focussed on stars. I used the focussing aid which magnifies the picture 13 times. You can then also monitor the vibrations of the image due to the shaking of tripod. This gives you an idea of how long you need to wait before the shaking has damped down to not cause significant motional unsharpness.

• I choose the highest F/2.8 aperture of my lens but you need to make sure the deformations at the edges of the image due to the lens imperfections are acceptable for the highest aperture setting.

• You need to shoot everything in RAW or RAW + Jpeg to get the most out of digital processing.

• As Matt mentioned, you need to have at least two fully charged batteries. In the cold the batteries won't last long.

• You need to be able to stand in the cold for a long time. The last thing you want is to get outside for an hour to test the best setting for the camera, to get cold feet and then have to warm your feet and shoes up for a long time when the aurora appears. I found that while good sweaters and winter jackets are easily available, good trousers and winter boots are often not available in shops. What you need are thermal underpants, thick down filled trousers and on top of that a windstopper. I found out that the ski pants I had bought were not working well for me and I had to improvise with putting a rain trousers over that as a windstopper.

Then the boots need to be the two component boots comprising of an outer and inner boot with the inner boot well insulated from the outer boot. Normal one component wintershoes, even expensive ones, won't work well if they sink a bit into the snow. The problem is that you are not moving a lot so your feet are not producign a lot of heat. You may not notice much after even quite some time but as time passes you can slowly feel that your feet are getting cold and then it will take a long time to heat up your ice cold shoes to a more comfortable temperature before you can get warmer feet.

You need to have both flexible gloves for handling the camera and tripod and thick gloves to keep your hands warm. You need to be prepared that your thumb may go into cramp from exertion in the cold. You can try to prevent this by alternating the use of the right hand and left hand thumb right from the start.

Some pure examples (no digital porcessing applied here):

I have more pictures uploaded here.

Answer 4

Beyond the technical aspects of setting up your camera(which has already been covered by Matt Grum quite well in another answer), the atmospheric conditions are an important component that you will want to understand.

The Kp Scale, Kp Index, or NOAA G Scale are reasonable ways to summarize the global level of geomagnetic activity. The Kp Index can range between 0 to 9, with 9 indicating the highest amount of geomagnetic activity. Typically to achieve a good aurora images, you would want a Kp Index of 4 or higher.

This is my favorite website to check the current Kp Index: Spaceweatherlive.com But also worth checking out are: Spaceweather.com and SolarHam.com

Your distance from light pollution is very important when capturing auroras. I would recommend using the Dark Sky Finder (USA only) and trying to be at a minimum darkness of the blue areas of the map. This means that almost the entire eastern United States is not a great place to photograph auroras! You could still do it, but it just won't be optimal with all of the light pollution. The lights only occur from about 50-400 miles above the earth's surface, so light pollution isn't quite as impactful as star photography, but it still plays a role.

Another option to assess light pollution is the Blue Marble Navigator, which works worldwide.

Answer 5

Things that's catch you out, from recent experience and echoing some of the above. As all the photographic setting's side has been pretty much covered... This is primarily assuming your going to be shooting somewhere quite cold and a remote dark location.

Take a second camera! Beg, Borrow, Hire a second camera, if anything like me you travel thousands of miles to Norway specifically to photograph the Aurora and your camera dies you'll be devastated! Don't think "It'll never happen to me" I had two cameras with me on the shoot. A great show of the lights in Alta, Norway about 3/4 of the way through the shoot the D700 (which has a very low shutter count) died with "Error" possibly due to cold. Thank goodness I'd packed the D300 too! Take a lot of batteries they die considerably quicker in the cold. Keep them in a pocket next to your skin, so your body warmth keeps their temperature up. Buy more than you have already, you will kick yourself if your batteries die before the Aurora does.

Working at night! Take a headlamp and modify if required with a red lens (this can be done with repair tape for car tail lamps) Make sure its simple to operate (Big On / Off buttons etc.). Why red light? Well red light helps your eyes recover quicker than from a show of white light. Also take a torch (with coloured lenses if you have them) and lots of spare batteries for torch and headlamp. Remember to turn the lamp off when you're shooting. You can also use a torch for light painting the foreground if required. Take a couple of chemical glow/light sticks in case of emergency, if your torches are flat by the time you come to pack up and walk back, you'll be stuck without a light source.

Take a 3ft or so, square of brightly coloured Rip Stop nylon (or similar), when you get to your location put it on the ground (Snow) to put your camera bag & kit on. This keeps your bag drier and gives you somewhere to place items when you take them out of your bag less chance of loosing something.

Working with your kit on, go out at night and practice photography at night up front, especially if you have never shot at night before. At night everything is different, Looks different and operating a camera wearing 6 or 7 layers is very different. Know your camera inside out and where all the controls are... Set up the camera to the basic night photography (Aurora) settings before you set out.

As per other answers, get really good boots and thermal socks, and don't just believe some salesman that says their good! Remember you are likely to be stood in the snow probably for hours. If your anything like me you wont want to leave your cameras and go and warm up somewhere, so your effectively rooted to the spot. Test your boots and socks BEFORE your trip. The cold will kill your trip stone dead if your freezing and cant stand the cold any more, and that would be a disaster if the Aurora was still in full flow. Many Togs around me packed up because they couldn't hack the freezing -21 temperature.

Get some GOOD gloves, flip top mitts that leave the top of your fingers free to operate the camera, I used Lowe Alpine Turbine Convertible Mitt with pure silk ultra thin liners underneath, with the option of snow mitts to cover the lot if it got serious cold.

Take some hand warmers not only can you use these to keep your hands warm, they can also be used to stick in your socks, or keep your batteries warm, and stop your camera freezing up. Get a spare fleece snood! Once your camera is set up you can put the snood over the camera and still be able to access the controls. This will help to stop it freezing and if you slip a hand warmer inside this will help too.

Don't forget to take some food and drink! Chocolate, energy foods, and if you have the option hot soup and or drink in a thermos flask or take a camp stove.

Check your tripod. If its not got an insulated leg or legs then wrap at least one of the legs with foam particularly if its Aluminium. Use pipe insulation wrapped over with something like a tennis racket handle grip tape or similar. On my second camera the Ali tripod leg froze to my hand when packing up! You might want to make sure you have spikes on your tripod feet for better stabilisation in the Snow.

Take your UV or lens protection filter off for the duration of the shoot, this stops condensation getting trapped between the front element of the lens and the filter. Don't try and take this off halfway through the shoot it will be difficult and might have frozen to the lens threads. Use your Lens hood for additional protection and help stop the front element frosting.

Be careful with remote releases (Also remember spare batteries for this). Remember in extreme temperatures the cables can become brittle and break at the plug. If your planning a extremely cold trip perhaps insulate the cables. In fact anything plastic could be subject to becoming brittle that includes Camera socket covers, plastic parts on a tripod etc.

Regarding your proposed location... If its possible to recce your shooting location in daylight its a real help, things look very different at night and if you are out in a remote dark location setting up some landmarks or placing some markers can really help you when you return in the dark. This also gives you the opportunity to get an idea of composition for the shoot. Its also sensible from a safety point of view, a recce could prevent you setting up on a crust of thin ice over 2ft of snow. You usually only find this out when you stab the feet of the tripod into the ground and you drop 2ft into the snow!

After your shoot, introduce your camera back into warmer temperatures gradually, don't just wack it straight into a hot room. Leave it in a cool lobby in the camera bag so that it gradually reaches room temperature, perhaps moving the bag gradually into a warmer place. If the camera was subject to frosting up (Mine were white!!) I wipe them down with a microfiber cloth then I put them in a sealed bag containing a large bag of silica gel to take some of the moisture away.

Hope you find this useful Regards Steve