I just returned from helping lead an incredible trip with AlaskaPhotoGraphics in the arctic of Alaska. Patrick and I met over 20 years ago guiding photo workshops in Alaska, and it was great to finally get to teach together again. Patrick has lived in Fairbanks for 30 years, and has shot aurora longer than most. His ebook is the definitive guide on northern lights photography.
During our daylight hours we processed the northern lights images we had taken during the night. And one thing became very obvious with photographing the northern lights; it’s all about the green channel. Since many of the aurora displays are green, you need to turn on your RGB histogram and evaluate the green channel for proper exposure. To avoid blown out highlights, you need to be very conservative in how close the green channel approaches the right side of the histogram. We found that if the green channel even touched the right side (bright) of the histogram, the aurora was too blown out when we opened it in the computer. Even though technically the channel wasn’t blown out, the green was too bright, and didn’t look great after you toned down the highlights. For the best results, we left a small gap between the green channel and the right side of the histogram. Often the image looked very underexposed in the field, but mid tones and darks were easily brought back up in LR or PS.
If you want to learn more about this, and tons more on photographing the aurora, I highly recommend reading Patrick’s ebook on photographing the northern lights. And if you want to photograph the northern lights, join me in Iceland this September. Last year’s trip had great displays!