Here is a simple tutorial on how to make a photo of an aurora and what do you need? As for start first I have to explain the basic.
What is the Aurora?
Auroras, sometimes called the northern and southern lights are natural light displays in the sky, particularly in the high latitude (Arctic and Antarctic) regions, caused by the collision of energetic charged particles with atoms in the high altitude atmosphere (thermosphere). The charged particles originate in the magnetosphere and solar wind and, on Earth, are directed by the Earth’s magnetic field into the atmosphere. In order to see an Aurora, one usually needs a dark sky (no bright moon, no city lights) and relatively clear weather. Auroras usually occur near the magnetic poles of the Earth and by the statistics most often during the equinoxes. The auroral zone is typically 10° to 20° from the magnetic pole defined by the axis of the Earth’s magnetic dipole.
There are 3 most important things that you need for making photos of aurora, so I will try to stick and explain more about them, but also include other “less” important stuff that you need to take with you.
- Camera (much better to have some DSLR) and mostly I will speak about this cameras;
- Wide angle lens.
The main requirement is a tripod. Your exposures will be at least 10 seconds but mostly even more, there is no way to hand hold the camera and get decent results without blurring the phtoo. It is preferred to have a sturdy tripod that you can easily operate and won’t make vibrations due to ground movement or wind. Of course this kind of tripods are much more difficult to transport, especially since everybody will come by plane, so the best recommendation is to have a normal tripod, but fairly stable and easy to transport in the baggage and also around where we will go to make the photos. Don’t take the small pocket tripods as they are not suitable for DSLR cameras and usually require an elevated position to put them on, so you will be able to look through the viewfinder.
Any good DSLR that is capable of relatively low noise long exposures will work well for the task. Many other digital cameras will work as well. If you’re not sure if your camera will suffice, take it outside at night and take a few tests photos with exposures at ISO 1600 or more (if your camera has) and make an exposure of around 30 sec. Pretty much all DSLRs on the market are known to work well for long exposures.
Wide angle lens technically refers to anything under 50mm of focal length. Essentially this is what enables you more field of view when you look through the viewfinder or LCD screen of your camera.
It is possible to work with 50mm but I recommend having a lens that has a focal length of 35mm or less. You also want to use the fastest wide angle lens you own. Most consumer wide angle zoom lenses are f/3.5 or f/4.0. A f/2.8 or f/2.4 is much better, but not everybody has this ,let’s say, professional photo gear, so any kind of wide lens will be ok. If you still have an old 50mm prime lens laying around, dig it out – it will probably be the fastest lens you own. The problem with a 50mm lens is that it isn’t wide enough to capture the full band in most auroras. Serious aurora photographers usually own at least one f/1.4 wide angle prime lens. These can be somewhat expensive, and very specialized.
Now to explain why it is good to have a fast, wide angle lens? Auroras usually last for longer periods (minutes, hours) so even with a slower lens and longer exposures you will get it on your camera. The trick here is to catch the fine details that occur in the auroras due to the magnetic field. The faster the exposure the less blurred this details will be. Of course, sometimes also longer exposures can get the beauty out of the aurora. So don’t despair. If auroras will be on the sky and you have some DSLR camera for sure you will catch it.
Focusing your shots
One of the first things you need to do. Forget auto focus once you start photographing in the darkness. It is time to set your focus on ‘M’ for manual setting. The subjects you will be shooting are too dark for the auto-focus to detect them. Since you main subject will be the very distant aurora then you need to set your focus on infinity. This is done by either having lens that has a really accurate focus scale or better to focus on infinity during daylight and mark that setting on your lens with a pen.
In some cases you will have distant bright subjects visible from where you shoot such has distant farm house, the moon or some other artificial light. You can point your camera towards this light and use auto-focus to focus on it. After your camera has focused switch your lens back to manual and use this setting. Be careful not to touch your focus ring or to tilt your lens to much downwards as this can change the focus setting. After you shoot your first shots make the focus check if it is accurate on your camera preview of the image. Nothing is more frustrating than a series of great but out of focus images. Believe me about that. You do a lot of photos in the night and when you see them on the computer they are out of focus. Every astro-photographer has got this treatment at some point of his life.
The idea behind using a fast lens is to reduce the shutter speed by as much as possible. Auroras can have lots of interesting details in their bands and rays, but these details are largely lost with exposures in excess of 30 seconds – the wonderful color is still there, but longer exposures turns the details in to blobs of colors.
So you are almost set up: you have a tripod, lens opened all the way, ISO set high, focus at infinity – now you are ready to start shooting. Probably should start at about a 20 second exposure and adjust from there based upon what I’m seeing on the histogram. Exposures can really vary widely depending on the brightness of the aurora and moon. The proper value depends on your camera/lens performance and the light that it will get from the aurora, moon or any artificial light.
Speaking of the moon, a moon lit night can be very helpful at lighting up the surrounding countryside so it will create better composition possibilities. It is much better when you have not to many contrast in lightness between the landscape and the sky. But the problem of the Moon is that reduces the beauty of the aurora due to the light. During our trip the Moon should not so much intervene with our aurora search since the events are set to be when the moon is in the lover fazes.
Too many Aurora images focus too much on the Aurora display itself. There are a lot of Aurora images out there so to make your image stand out you will need to add interest to it by having something interesting in the foreground. Including a mountain, tree or other subject matter can help aurora photos. It is nice to have a reference point for scale. Experiment, horizontal and vertical, include the moon and leave it out, including the surroundings, even shoot straight up, anything goes.
Other useful tips
Be aware that usually when you want to make photos of the aurora you need to go in the middle of the night in some frozen landscape at the far north or the far south so you will need good winter clothes. We will be in Finland in the middle of winter. Still haven’t been there, but my guess is that you can expect temperatures of -15 to -30 even -40 degrees centigrade during the night. Dressing warm is essential. And get yourself mentally prepared to wait out the night. I have spent a lot of nights under the sky, and even in summer at southern European latitudes as it is in Macedonia you are starting to get cold, so winter conditions are on the extreme. If you get cold try to move as much as possible to better your blood circulation. Good winter boots are critical. Make sure they do not fit tight. They should have a substantial base depth to them since you are often standing on cold ground in one place for long periods. In my experience the cold first gets from your feet, so the better insulation you have for your feet the better.
If you have a remote shutter for your camera it is also good to take it. Prevents camera shake and allows for exposures in excess of 30 seconds. (Some wireless remotes only offer exposure options of 30 seconds. Make sure to check the version you have if you plan on using a wireless remote).
Batteries. Your camera will be out in the cold. Cold reduces the battery capacity by few times. Have a few batteries at your disposal. Keep on warm inside your pocket the spare ones. Not to drain out the batteries a good practice is to have at least 2 and to switch them once you see the one you are using gets to the low levels. During you are shooting with the other one warm the other as much as possible.
Almost every DSLR has a built in noise reduction setting. Should you use it? My recommendation is not. There are some nice programs that can get the noise level really down on your long exposure files. What does the noise reduction setting do, is taking another exposure with the same time as your previous with just the curtain down. During this time you can miss some interesting detail in the Aurora. Also you can make dark frames before or after you finish shooting with the same exposure as your light (aurora) photos and after use them to take the noise out. Also try to shoot in RAW (uncompressed file) as will give you more opportunities to process the photos later.
Suggested Camera Settings (as mentioned before this can vary a lot)
Daylight White Balance
Lowest F value you have. If F/4.0, 30-40 seconds or F/2.8, 10-15 seconds
Low LCD brightness
Of course this are some predetermined good values, but there can be lots of variables that can change so you will have to readjust the camera values. Today’s cameras have one advantage than the old SLR (analog) cameras that you can see the photo just after you take it and if you are not satisfied with the results you can adjust the settings and take another shot.
Note about the point and shoot cameras
While it is not impossible to photograph the aurora with a little point and shoot digital camera, it is challenging indeed. The models are constantly changing, and perhaps in the near future it will become easier. A few of the basic limitations of most point and shoot cameras are:
If you have camera with some advanced features, read your manual and see if it looks usable for aurora. You want:
400 ISO, preferably 800 or higher
Manual focus option
Self timer release
Wide angle lens
Hope this will help you to prepare your photo gear for the trip to Finland. Of course there will be additional photo lectures and at the spot practice to make sure that you will get the best possible results of your aurora shots with the camera gear you have.