Photograph the aurora: the camera
To understand which camera is best for photographing the aurora, it is essential to know what we need to do. When photographing at night it is necessary to get the right amount of light to the sensor without the photo being too noisy to do so, we have the following 3 elements available:
I will not stop here to explain the meaning of these three parameters assuming that you already know them well and therefore you know that in order to act on these elements the camera must be able to have manually adjustable exposure times up to 30 seconds, a lens capable of collecting as much light as possible and a good behavior using high ISOs.
There is also another important element to consider, the sensor. This must be of good quality but does not mean, however, that it must necessarily have a greater number of pixels.
That said, since our aim is to photograph the Northern Lights, we must choose cameras with low noise and high ISO and, as I said before, they must have long exposure times and a fairly bright optics.
The choice therefore necessarily goes to reflex or mirrorless.
I shot both with a Fujifilm GFX50S and with a Nikon D810 and with a Sony 7RII but nothing prevents you from shooting with an entry level.
– A stable tripod
– a bright wide angle lens
– spare batteries
– a remote control
– an eyepiece cap in case you use a reflex
– a flashlight
Do not underestimate the tripod, we shoot with a shutter speed greater than one second so it needs to be very stable also because the wind in those parts does not joke and can play tricks.
It is therefore essential to photograph the Aurora.
If it has rubber knobs it is better, the tripod becomes very cold at those temperatures and also make it easier to grip. Another useful accessory is the spirit level but not essential as now all cameras have one.
Since we have to photograph the Aurora, or a landscape, we need to use lenses with short focal lengths, wide-angle lenses as they have a wide viewing angle
There is no better focal length, it depends on personal taste, but keep in mind that the wider it is, the more there is the possibility of introducing distortions, especially on the edges. I have used from 14mm up to 23mm in medium format. Lenses with an aperture equal to or less than f / 2.8 should be preferred as they must let as much light as possible pass through in the shortest possible time.
The cold is the enemy of batteries and their duration is directly proportional to the temperature, the lower it is, the shorter their duration will be. In the Nordic countries, temperatures are around -20 degrees Celsius and therefore the batteries will suffer a lot.
Obviously you need a backpack suitable for carrying all your equipment to photograph the Aurora. Make sure it is waterproof because you will place it on the snow. It can also be useful to hang on a tripod to allow for greater stability. A tip … Leave your backpack in the car when you return to the hotel, bring only your memory cards with you. Unfortunately, the sudden change in temperature creates condensation on the lenses and on the camera and makes it unusable for a long time. Leave it in the cold without problems and do not be afraid of thefts, they do not steal from there.
In order to have still images you need to prevent vibrations and pressing the shutter button can ruin a wonderful image. Therefore, equip yourself with a remote shutter release or, alternatively, use the camera’s self-timer.
If you are using a reflex camera, it would be advisable to cover the eyepiece to prevent the light from confusing the sensor. If you don’t have a black ribbon, that’s fine too.
To photograph the Northern Lights you need to be in the dark and therefore it will be very difficult to set up your camera. A headlamp may be in your car but make sure there is the possibility of having a red light otherwise you will be blinded by the glare of the white light.
As a basic configuration you can use these parameters:
Auto focus light: OFF
Vibration reduction (if present): OFF
Noise reduction: ON
White balance: 2900-3200k (but this can be changed later in post-production
File saving: RAW
ISO and shutter speed
As already mentioned above, the ISO must be as high as possible, but avoiding the loss of detail. To start, a value between 800 and 3200 should be fine. The shutter speed must be long but not so long as to have those boring streaks of stars.
There is a simple formula to find the maximum shutter speed and it is the rule of 600 (on full frame or 500 in the case of APS-C). It consists of dividing 600 by the focal length of the lens used, so with a 20mm lens on full frame the maximum shutter speed will be approximately 600/20 = 30 seconds. It should be borne in mind, however, that the effect of the rotation of the stars is lower near the North Star and greater at 90 degrees from it. So let’s start with the ISO values sector from 800 upwards and shutter speeds from a few seconds to a few tens of seconds.
If the aurora is very intense, you can go down with the ISO to have greater clarity or go down with the shutter speed to better fix the movement of the aurora.
Some photographers instead of manually setting the shutter speed leave this task to the camera, shooting in “aperture priority” mode by rectifying the exposure on matrix or multizone.
However, it is necessary to do some tests because very often it will be necessary to adjust the exposure compensation to negative values. You can better control the correct exposure by lowering the brightness of the display and checking the histogram. The latter will give us information on the distribution of shadows, midtones and highlights within our photo.
The histogram is a graph that shows, starting from the left and going to the right, the amount of dark pixels, with low light, with medium tones and with highlights. A correctly exposed photo should have an even distribution without dark or overly saturated pixels.
However, it is not always possible to have such a situation because the range of light that the camera is able to capture is limited compared to the real world. If in a photo there are areas of strong shadow and strong light, inevitably you will have to give up on viewing one or the other correctly.
More about exposure
Dark or saturated pixels cannot be modified in post production and therefore in the final photo we will have burnt areas, completely white or completely black. This means that it will not be possible to restore a shaded area or one that is too bright.
A useful technique for exposing correctly is that of right exposure, that is, making sure that the histogram reaches the right end without going beyond it. For my personal choice I prefer to straighten the camera manually to have a certain consistency in the shots.
If you like startrail it may be useful to increase the exposure time beyond the limit that allows you to have pinpoint stars. You can achieve this effect with a single photo with a long exposure (30 minutes) or add a large number of shorter exposures. In the first case, I recommend that you close the aperture to f / 8, f / 10 and lower the ISO because with long exposures you risk saturating the background of the sky which in the end will be too bright. The second option instead allows you to keep the sectarians seen so far and take advantage of a software like Startrails to add up the sequence of photos.
It must be said that startrails with the aurora can only be achieved if the latter is very static, otherwise you risk having a totally green image.
Opening the diaphragm
You know what a diaphragm is, the more you open, the more light enters. It is also true that at maximum aperture the objectives do not perform excellently, so it would be advisable to close them by one or two stops. Evaluate the situation to understand what is best to do. On a full moon night it can be useful but with a completely black sky it is not.
This is a delicate topic and requires a lot of attention, but don’t worry because just a little practice is enough. The first thing to do is to set manual focus, both on the lens and on the camera. Then a bright subject is needed at such a distance that it can be considered infinite. A street lamp or even the Moon can do for us. In extreme cases, it is necessary to aim for the brightest star.
Exercise before trying your hand at the dawn, any evening can be fine. Or, better yet, try it during the day so you can learn the technique better so you don’t have problems with low light. However, use a tripod, even during the day (and disable lens stabilization).
Focus and more
Activate live view and zoom in on the framed object to focus (remember to disable autofocus). Rotate the focus ring slowly back and forth until you find the right focus. Take the picture and check that the focus is correct. The lens should indicate the exact distance that corresponds to the focus at infinity, mark it and possibly use a piece of tape to make a mark on the lens to get the correct measurement. Normally the indicator should stop just before the infinity symbol but this is not always the case, especially with zooms.
Check the focus often because it can also be influenced by the external temperature, so a quick check before shooting is advisable. If you use very bright lenses, that is, below f / 2.8, the situation becomes complicated as the depth of field is very low and distortion problems can arise at the corners of the frame.
Low temperatures can create a lot of problems for your equipment. Care should therefore be taken. Never ever approach the lens with your face, your own breath is enough to leave a layer of ice on the lens. The breath condenses and freezes immediately. The cold is also harmful to the liquid crystals of the monitor which stop working at low temperatures but as long as the machine is switched on there will be no problems. However, if you keep it off for a long time or if the temperature drops below -30 degrees centigrade, you will notice a slowdown in the display.
Protect your camera, perhaps with a scarf. Another serious problem that can arise is the formation of condensation when returning to the heat after finishing the photo session. The abrupt transition from cold to hot inevitably brings water droplets to the lens. I usually leave the equipment in the machine carrying only the memory cards with me so I avoid condensation problems that would make the machine unusable for a long time.
Another problem you will have in cold weather is battery life. At low temperatures they do not last long so bring some spare batteries.
The Aurora is unpredictable, or almost … Photographing the Aurora is a privilege. Fortunately, there are some very efficient tools in the Nordic countries for monitoring weather and solar activity.
I use these which are very reliable:
- www.yr.no for weather forecast (never wrong)
- www.n3kl.org/sun/noaa.html for solar activity
The latter shows a graph that gives information on the current magnetic activity detected by the Trømso magnetometer.
Just follow the activities of the lines to get an idea of the power of the aurora (measured in kp which is the aurora index)
There are also some apps for the smartphone but they are not as reliable as the sites I mentioned above.