It’s that time of year up north here in Alaska, the aurora is putting on a show again. The other night Cree and I watched the northern lights over our house, and this week they should be visible far to the south in the lower 48. We can’t wait for aurora season, and with fresh snow on the ground, let the night photography begin!
We just had a question from a friend who was trying to figure out how to focus at night for the northern lights. Before mirrorless with DSLR cameras focus often required finding the infinity focus on your lens during the daytime, gaffer tapping the lens so the focus wouldn’t change, and using this preset in the dark at night. But mirrorless technology, specifically lens focus by wire (mirrorless lenses), have changed things for the better.
Mirrorless lenses focus using an electronic signal rather than a direct mechanical function to move elements in the lens. On many mirrorless cameras there is a setting that will default your lens to infinity every time you turn it off. So if you have a setting called ‘recall focus position’, make sure to turn it off for aurora photography (you might want to recall focus position for other situations). This means when you turn your camera back on your lens is set to perfect infinity focus. The next step is how you engage autofocus. I use back button focus, so when I touch the shutter this will not change my focus from infinity….focus only occurs if I use my back button. It you use your shutter button to focus, then you need to switch this off or possibly turn the autofocus off using a hard switch on the lens.
So how do I focus a -40F in the dark with big mittens on? It is real simple…I just turn my Nikon Z9 off and on, and I know my lens is set to infinity focus. I’ve shot thousands of aurora photos this way, they are tack sharp. Just make sure your shutter doesn’t engage autofocus, and your ‘recall last focus position’ is turned off in your menu. Nikon, Canon and other systems all can focus this way.
Of course you can still zoom in on a star and focus, or use the moon or a bright object nearby. And if you use a DSLR then you will still have to find infinity focus on the lens and gaffer tape it down. But with mirrorless cameras it can be as simple as turning your camera on and off. We just had one spot open on our northern lights trip to the arctic next February, come join us!