Photographing the Northern Lights: The Ultimate Background
Northern lights photography is all about capturing the heavens, right? All that information about photographing the Northern Lights teaches you how to work with large apertures and high iso settings to capture the essence of the dancing light show above your heads. If you get it right, it is the aurora that will make the image and dominate the frame. All good photographers should know that a background complements a subject and a foreground compliments a background. The Northern Lights are one of the ultimate backgrounds. This article considers 2 techniques to make more of the foreground in your Northern Lights scene.
[Related Reading: Exposure Balance In Landscape Photography – What To Do To Get The Perfect Exposure]
This photo was taken on a really dark night at Vestrahorn Mountain. It was so dark because it was a new moon and the only light was from these weak auroras in the distant North. This is one of many shots as we were waiting for the lights to become more active. The shutter speed for this shot was 38 seconds. I am only allowing 20 seconds exposure on the sky, then cover the top half of my lens with my Magic Cloth to prevent any more light coming from the sky. I am shooting in ‘bulb’ mode so now that the sky is exposed, I can take as much time as I like to carefully expose the foreground as long as my cloth is moving around the bottom half of my lens systematically. But, like most things photographing, it is not that simple. I have to keep my attention on the sky while I am doing the magic. If the aurora activity picks up, I have to stop the current exposure and start again… 20 seconds on the sky then hopefully some minutes on the landscape. In the shot above, the landscape has twice the exposure of the sky, but it is still far too dark to communicate the shapes and forms in the foreground. I was thinking that I need an extra minute on the foreground to get usable details. This is the Magic Cloth Technique one of the best Night Photography filters.
[Related Reading: Many Have Photographed The Aurora Borealis, But Who Has Photographed STEVE?]
My shutter was open for 98 seconds for this shot, so that’s 20 seconds on the sky and the foreground was exposed for most of the time (I am moving the cloth up and down over the bottom of my lens so nothing is getting the full 98 sec). The photo has been processed to lift the shadows, but it is clear that I wouldn’t have got this detail with a 20 second exposure.
Editing The Multiple Exposures
Because the night photography exposures can be so long, it is better to have a ‘Merge Multiple Exposures’ mind set than a ‘HDR’ mindset… IMHO. I would suggest an exposure for the sky, then an exposure for the foreground and leave some room for post-processing. Here is a foreground exposure of 225 seconds at the Grotta Lighthouse in Iceland. I was with Canon 10-22mm at f/3.5 on a crop sensor and 640 iso.
The sky exposure was 25 seconds. In Adobe Lightroom, I boosted the shadows. Hopefully this will match the foreground exposure and the blend will be more natural. I am going to blend them manually in Adobe Photoshop.
In photoshop, I have both images in a stack with the sky exposure below and the foreground exposure on top. Then use a channel selection technique to select the brighter pixels in the foreground exposure. On a PC, hold ALT+CTRL+2 which selects the luminosity channel. In this exposure, the sky, the lights, the sea and brighter parts of the landscape are selected.
A simple click on the ‘mask icon’ turns the selection into a mask. See the black and white thumbnail on the second layer? This is the mask created from the selection and it is allowing parts of the sky exposure through. In the black areas, you see the image beneath and the white areas, you see the image on top.
Both techniques have a similar downside that you can miss a lot of good photographs during the foreground exposures. Time, opportunity and patience is the solution to this drawback.
Have you shot the Northern Lights before? Have some Aurora shots and techniques you’d like to share? Let us know in the comments below!