Generally, I like to limit my photo editing. I like that my camera captures a little slice of reality. However, when it comes to the aurora, the camera distorts reality somewhat as it is. All but the brightest aurora are visible to the naked eye as a faint green smudge. Most of the time, you'd miss them outright. But the camera, by virtue of being an integrating sensor, records detail I could never see. Imagine the header picture five stops underexposed, and that's what I saw when setting up. Composition is a guess. Because of this, I like to take more liberty with my editing of the night sky in an effort to bring it out and make it everything the sensor can see. Here's how I do it.
This is the original image. I shot it on a Nikon D7000 with a Tokina 11-17mm lens at 11mm focused at infinity. F/2.8, ISO 640, 5600K WB, 20s. The ISO is a bit low because I forgot to set it, so the image is a bit darker than I prefer. But it'll work. I'll be processing with Lightroom CC and elements from the Nik Collection (Sharpener 3, Dfine 2, and Color Efex Pro 4).
The first step is the most dramatic. I import the RAW into Lightroom, and then...
- Exposure +1
- White Balance to 5300, correct the color of the sky
- Lens profile correction
- +10 dehaze to minimize errant power plant exhaust
Next up is a round of sharpening with Sharpener Pro 3. I use 50% adaptive sharpening, and leave the rest alone.
The D7000 is not a clean camera noise-wise. It's fine at high ISO indoors or where there's actually light, but point it at the sky and it's all crap. ISO 1250 is the highest usable ISO for this, which is just sad. Even at ISO 640 there's a fair bit of noise, so I run the image through Dfine 2's automatic noise reduction. Usually it does a good job without any input from me.
After that, it's into Color Efex for some tweaking. Here's the detail extractor run at +4, with 0 contrast and 0 saturation.
Next is tonal contrast, +0 highlights, +4 midtones, +8 shadows.
Finally, the brilliance/warmth filter. 0 saturation, +12 warmth, and +8 perceptual saturation to activate it. The only problem is that it gives the whole sky a purple cast...
...So once back in Lightroom I bring the temp to -10 to fix it. Notice that the snow is still red, but that's from the red lighting on the buildings around me.
Overall, it's quite an improvement from a series of small tweaks. It's possible to really go nuts with the edits, but I don't like that look. I save everything here (except the exposure correction and crop) to a preset, and use it as a starting point for aurora images. I hope this is of some use, or if not then at least interesting.