With a host of people heading north this winter/spring to photograph the aurora, I thought it might be of some interest to talk a little about the process of shooting photography at night; I know a lot of people have little experience with that, and it really can be a challenge at times. Particularly on a cold frozen night in Alaska when the northern lights start going crazy overhead.
So, the first thing I’d suggest, if you haven’t already, is read over my 3 part article on shooting the northern lights. There’s a downloadable PDF at the end of that article you can keep for future reference.
So, now that you’re prepared, consider the moment. It’s dark. It’s cold, maybe minus 20 degrees F; cold enough that your hands start to really feel it after a few minutes. It’s dark. You have a headlamp on, and that gives you a little bit of vision out to maybe 30-50 yards or so. After that, you can’t see too much at all. The aurora starts to fire up, and you want to shoot it.
You can’t see your foreground and composition. Its dark. You don’t even know if the foreground is worth shooting. It’s dark. You can’t walk around all over and use your headlamp to see, because (a) there isn’t time, (b) there are other people trying to shoot, (c) you don’t want to track up all the snow by stomping around in it. So setup your test shots. This is probably the most important part of the process. Set up and do your test shots.
Increase your ISO. I feel pretty good using either my D700 or my D600 at ISO 1600 for northern lights photography. That’s a pretty good ballpark to start with. So, for my test shot, I jack the ISO up all the way; whatever it goes up to; ISO 6400? ISO h1, h2 h3? On my D600, it’s HO2.0 – 4 stops higher than 1600. I turn Noise Reduction off. And I crank DOWN my shutter speed; if the correct exposure is, say, 1/15th second at HO2.0, I’ll add maybe 2-3 stops .. so let’s just say 1/2 second. That’s way over what the correct exposure should be.
But … the brighter image that results helps me review the LCD more closely for the test shot. I’ll take a shot.
Review the Scene
I’ll use the test shot method to discern whether a location is even worth shooting. Driving down the road at night, the aurora kicks on, and I’ll pull over at the first available location to shoot it. I’ll do a test shot or 3 to review whether the scene works or not. I don’t worry about fine tuning focus here, my first priority is ‘does this scene work for me?’ If not, I’ll take one more shot to make sure; can I turn around and shoot further to the left, right, etc? No? Then back in the vehicle and move on. There’s no point shooting a scene that doesn’t work for you (unless the aurora is so absolutely mind numbingly amazing right then and there that I have to shoot it anyway, of course).
So I drive down the road and find a nicer location, maybe with some nice spruce trees in the foreground, or a cool mountain ridge beneath the sky. Stop, test shoot, and review the scene.
Is it sharp? No? Fix my focus. I don’t care how crooked my horizon is if my photo is out of focus. So I’ll fix my focus (read the article linked above, closely, for info on focusing at night time). Shoot another test shot. Is it sharp? No? Then fix my focus. Repeat. When I’m confident my focus is on,
I’ll check things like the horizon. Is it level? No? Fix it. Shoot another test shot. Is it level? Yes? Awesome.
Now I fine tune the composition. Is the composition something I like? No? Then change it. Don’t fix it, change it. More than likely, it’s not right. So adjust it. Get rid of that weird branch coming in from the side, the footprints in the snow in the foreground, the dead tree sticking up into the frame. Remember moving my location will mean I have to check my horizon again, and possibly my focus as well. But get it right, don’t stay in one place and shoot simply because that’s where you stopped and set up.
Now, my image is sharp, level, well composed? Awesome. I’ll start figuring the correct exposure. I’ll bring my ISO back to the ballpark I want it to be in (approx. 1600, usually). Adjust my shutter speed and fire another test shot; review the histograms. Historgam”s”? Yes .. the RGB histogram, Red Green and Blue. Don’t waste your time looking at the single luminosity histogram; you NEED to review the RGB histograms (this is one of the most common mistakes I see photographers make). Do I need to touch it up? Probably. Tweak it, test shot again. Get that histogram correct.
Now that I have this epic histogram, I know my exposure is where I need it to be. Do I need to turn (long exposure) Noise Reduction on? Well, maybe. Some folks I know say no. Some say yes. A general rule of thumb is exposures over 4 seconds might require NR turned on. The problem can be that it effectively doubles your exposure time between shots, turning a 4 second exposure into an 8 second shot, and so on. If you’re taking 30 second exposures, that means one minute between shots. That can mean not shooting an awful lot of photos.
On the other hand, some folks say that temperatures in the vicinity of 0 degrees F and colder, NR really isn’t an issue, because the sensor doesn’t heat up enough to yield noise anyway. This is somewhat camera dependent, so do some tests on your gear, if you can. I generally leave NR on if my exposure is over 10 seconds, but it also depends on how active the aurora display might be.
Now, take my final test shot. This photo should be right on it. Focused, well composed, level, correct exposure; I’ll review it closely to make sure I got it right. Good? Yes. So I leave everything as is, and shoot and watch the sky. I’ll review things as I shoot them, but be careful not to move anything, or adjust any settings, etc. Even bumping the tripod can mess up the horizon.
Now, I want to switch to a vertical shot? Move a little to my left? I go through the entire process again. Always, always, always shoot those test shots.
Remember -it’s dark. Don’t waste your time trying to capture what you can’t see. Use your camera and shoot the scene to get a view of what’s in front of you. Shoot those test shots. You’ll be glad you did.