The Aurora Borealis – The Naked Eye and the Camera
There is an interesting phenomenon going on with the Aurora Borealis or Northern Lights which I like to explain. Not that I’m an expert on the matter, in fact, I recently witnessed my second ever Aurora, so you can safely call me an amateur. Witnessing the Aurora was a lifetime wish for me and when my family moved to Scotland last year I was quite excited about the fact that there was a possibility for me to observe the Aurora in all its glory. The many stunning images on the internet with the amazing colours looked so beautiful, I just HAD to see it. I know many others have the same desire and in recent years the number of folk going to countries like Finland and Iceland to see the Aurora had increased considerably. You might wonder what the reason behind that is? Perhaps the increasing number of stunning Aurora pictures on the internet?
On Tuesday the 17th of March 2015 I received alert after alert warning me of a possible visible Aurora over Scotland. As the day progressed and the weather forecast started to look better the excitement builded up. With a cloudless and cracking clear sky we started the evening and I had found myself a nice and very dark viewing point near Foreland House on the Isle of Islay. Around 8.30pm I noticed a faint white and green(ish) glow on the horizon as well as overhead. A kind of pillars of faint white(ish) and green(ish) light in the sky. As I had my camera and tripod with me I tried to take a picture with a large exposure and I noticed that it showed more than the naked eye could see, that was quite a thrill for me. After a few more images I took one with a much longer exposure and when I released the shutter I noticed an amazing colour display which stunned me. That was not what I had seen in the sky but the camera picked up colours which I apparently could not see. Later that night, around midnight, the Aurora was very active and I noticed wave after wave rolling and pulsating overhead in the sky, I also noticed beams of light flickering, it was an amazing and unforgettable sight, but still almost nothing of the colours I had seen in the pictures were visible to the naked eye, they were there though in my camera. It turned out I took some amazing pictures while enjoying the fascinating light show.
The day after the Aurora Borealis event I did some research on the internet to try and find out why these stunning colours were not as visible to the naked eye as on the camera. As it turns out there is a logical explanation. “Human eyes can’t see the relatively “faint” colors of the aurora at night. Our eyes have cones and rods – the cones work during the day and the rods work at night. Cone cells, concentrated in the fovea in the central area of vision, are high resolution and detect color in bright light. These are the main cells we use for vision in the daytime. Rod cells, concentrated in the periphery around the outside of the fovea, can detect much fainter light at night, but only see in black and white and shades of gray. So the Aurora only appear to us in shades of gray because the light is too faint to be sensed by our color-detecting cone cells.”
As the human eye views the Aurora Borealis generally in black & white, modern DSLR camera sensors don’t have this limitation. If you then take into account the long exposure times and other settings on modern cameras you understand that the camera can pick-up much more of the amazing Northern Light than we do. To show you roughly what I saw in reality and what my camera picked up I have captured two images below. On the left the Northern Lights as I roughly saw them with the naked eye, without the movement of the sky of course, and on the right the picture from the camera of the same view with a long exposure.
Now does that mean that watching the Aurora Borealis was a disappointing experience? Certainly not, it was amazing to see the light swirling over my head, pulsating and flickering, and I enjoyed every moment intensely and it even exceeded my expectations, despite the lack of the amazing visible colour display. I must admit though that I was very happy that my camera showed me what I had missed making it an extra special experience. And perhaps, when you are further near the arctic, you do get to see a bit more of the amazing colour display but it will never be as in a DSLR picture. Like I said, I have witnessed the Aurora only twice so I’m far from an expert, but it was an event I will never forget and I wish you will be able to see it for yourself as well. Don’t forget your camera!