Jan 29

Written by:
Sunday, January 29, 2012 

This week's entry is all about the Northern Lights. Over the past two weeks, there have been a number of large solar flares... and if you monitor various websites, muddle through strange dials and calculations, and cross your fingers for clear skies, these flares can translate into wonderful light-shows over our Canadian skies. If the stars align and you're lucky enough to be outside late at night (or into the wee hours of the morning) and the lights apear, then as a photographer you have another challenge... how to get what Mother Nature provides, captured on camera for posterity.

Tuesday evening and on into Wednesday morning we planned to head out to try just that. So in the 24-48 hours leading up to the shoot (about how long it takes for any solar flares to reach earth), I decided to do some research into getting better captures. I've shot the northern lights a few times before and it always seems to be trial and error.  This time, as part of my project 52, I was determined to find those master shots out there and learn how they managed to get their results.  This was what I learned:

• Tripod and Remote Shutter Release are essential: As you are doing long exposures, the camera needs to be mounted on a tripod and a remote control used to trigger the shutter.  Without these items, the shake would be too much and nothing would be in focus.
• Remove All Lens Filters: Most photographers will keep a UV or clear filter on all of their lenses.  This is really standard practice to protect your investment in your equipment. Dust, dirt, sand, a drop off a tripod (*shudder*) are all instances where filters have protected that expensive glass from the elements (or clumsiness.)  Not to say filters will protect all, but better something than nothing and I was thankful I had a filter on my lens just this summer when I noticed a deep scratch across the front of it on one of my lenses.  Thankfully the filter was a whopping $50 so I could remove it and put on a new one and not be out the entire cost of a lens.  *whew!* BUT - for northern lights captures, you MUST remove all filters from your lenses that you're using.  If you don't, you'll have concentric rings appear in the center of every one of your images and they are next to impossible to remove in post.  I spent a whole evening and on into morning one summer on a beach shooting auroras but whoops... forgot to take off the filter.  When I got home to process, the entire set was useless. So take OFF your filters before you try to capture northern lights.
• Use a fast lens: To shoot Northern Lights, all the "experts" seem to agree that you MUST use a fast lens. f/2.8 or faster being ideal. You can shoot auroras with a slower lens (my wide angle is an f/3.5) but then you have to expose for longer to acheive proper exposure.
• High ISO: They also suggest using a high ISO setting in order to decrease the length of time your shutter must be open for... this allows you to capture more of the formations rather than just a solid green band in the sky that all blends together.
• Shoot Wide Open: Shoot with your lens wide open (seems a bit off to me as lenses are usually sharpest at a stop or two below full open but hey... they're the experts, right?)
• White Balance:  Here the experts all seem to have different opinions.  Many suggest daylight white balance will give you the most accurate colour captures, but in a few other locations, it was suggested that using Cloudy or even Flourescent were the way to go.  As I shoot in RAW I set mine to Daylight and figured I'd adjust in post as needed.
• Get Away from Ambient Light Pollution: The darker the better but definitely more than 100km away from any city lights.
• Don't Forget about your Foreground: Pay attention to foreground detail in order to give some sense of scale to your auroras and try to bring additional visual interest to your composition.
• Focus: Ensure you have proper focus... seems obvious but this is a lot harder than it looks when you're trying to focus on something you can't see in the dark. Its helpful to shine a bright flashlight on the object in your foreground you want crisp, lock your focus, and then turn off the light and take your shots. Be sure to re-do your focus if you move locations and even if you don't, check your results periodically as its really easy to bump the focus ring and have 4 hours of shooting end up wasted. Bring a GOOD flashlight with fresh batteries (and try not to drop it on the ground... really hard to find later.) The ideal focus is to set the camera to infinity, but on some bodies/lenses, this isn't quite right... try a shot at infinity and if the focus is off, bring it back from infinity in small increments until you find the sharp focus you're looking for.
• Basic Recommended Settings: The average settings recommended generally were ISO 800-1600, wide open (f/2.0-2.8) and a shutter speed of 8-10 seconds... but adjust as needed. Its always important to remember that the aurora borealis is constantly moving across the sky.  In order to capture those beautiful spikes and swirls, your shutter can't be open for too long.  The longer its open, the more blended the lights become.  That makes for some wonderful captures as well, but I personally prefer the definition in the lights so I agreed with this assessment.

Tuesday evening rolled around and, my head filled with settings, tips and tricks, I went out with a group of photographers try to implement these strategies.  But did they work...?

Our first shooting location was a parked train on tracks... this was earlier in the evening at around 10 PM so the auroras weren't very active (they dance best after midnight, usually.) We were not a long way outside the city (only a 10-15 minute drive) but far enough that the ambient light didn't seem to interfere. I put on my 25mm prime lens (not the widest I have but one of the fastest at f/2.8) and tried some test shots. I set the camera to infinity for focus and shot.  The sky really wasn't lit up very well at this time so I upped the ISO to 800 and tried again.  These were the results.... not so good but some green there. The biggest problem for me... the foreground was boring.

Shot at ISO 400, f/2.8, for 30 seconds	Shot at ISO 800, f/2.8, for 30 seconds

Our group decided at that point that the location wasn't quite right and since we were starting to see some more activity emerging, we needed a better foreground.  We headed down the road to an old abandoned farm yard with a barn and outbuilding that proved to be a great foreground for the bands of NL we were seeing. Not a crazy amount of activity in the sky but definitely noticeable. I determined that in order to capture the composition I wanted, my 25mm (50mm in 35mm equivalent terms) just wasn't going to be able to get what I needed in the frame. So off came that lens, and on went the 14-42mm, set to 14mm. I just broke my first rule - to use a FAST lens.  This one is only f/3.5 at its fastest so I shot with it wide open and hoped for the best.

The first test shot was done at ISO 800, f/3.5 for 30 seconds... Still pretty dark.	So up went the ISO to 1600 with the same settings as before. Though the exposure here seems to be much better, I was not happy with the noise produced.

Sometimes its hard to tell (with just your eyes) where the auroras are displaying, but with the longer exposures of the camera, you can pick up the green that your eyes miss.  We had a bit of a lull in activity in the sky, so I decided I'd move to a new location and run a test shot to see if any green could be found elsewhere... and had the happy occasion to capture a plane flying by during the time the shutter was open. I exposed for longer on this shot as I was trying to find any hint of green. Normally, unless you are looking to capture the movement of the earth's rotation, 30 seconds is about the max exposure before you start to lose those pin-pricks of light and instead get the trailing lights of the stars as the earth moves.

ISO 800, f/3.5 for 60 seconds
As you can see, the NL were only visible where I was shooting previously and no auroras were evident elsewhere.

I played around with a number of different locations, compositions and camera settings over the course of the night, finally settling near the end with a long-exposure startrail as the auroras just didn't reach the predicted activity levels we were hoping for. Following the various forecasts for auroras is helpful, but just like the weatherman, they aren't always accurate.  

I set up very close to my original location, put the camera in bulb mode, and just let it run for 8 minutes straight. I forgot to drop the ISO down (should have been around 200-400 for that long of an exposure) so the resulting image was very blown out, but thanks to shooting in RAW, I was able to pull the exposure back in post.

f/3.5, ISO 800, 480 second exposure at 14mm

Well there you have it.  I broke almost all the rules of shooting auroras: We were within 100 km of a city, I did NOT use a fast lens, I exposed for a lot longer than recommended, and the ISO they suggested was too high... who would have thought that this would be my favorite capture of the night!  I know that all the tips I learned will be immensely helpful on another night when Mother Nature decides to give us a real show, but in the meantime, it just goes to show that you can learn all you like about shooting a particular subject and be prepared to follow all the rules, but in the end you shoot what's in front of you and make the best of it.