What color is the night sky? It’s a fascinating and fun question to contemplate and discuss. The problem is that what our eyes see and what the camera sees can be completely different, and the image the camera captures is totally dependent on the settings of the camera, primarily the color temperature.
Here is an excellent discussion of the scientific basis behind the color of the night sky. The problem is that we can see the night sky in this way.
Please bear with me for a few minutes. It took me a long time to come to a conclusion on how I wanted to present the night sky.
There is a difference between:
1) What physics says is the color of the night sky (we cannot see the real colors because our night vision is mostly in B&W). Please see the article above.
2) What we perceive the night sky color to be. Our eyes are poor light receptors at night, and we see primarily in black and white. Our color receptors do not work well in dim light. Also, what we actually perceive may not be what we remember. By the way, different people have somewhat differing ability to see color at night.
3) What we remember the color of the night sky to be. For events that we see repeatedly, like looking at the night sky (or going to the beach, etc.), it has been shown that we do not remember every detail of every instance. We may remember the meteor we saw that night, but our memory fills in the background details, like the color of the night sky, the smell of night air, the feel of chill on your skin, etc., with a mixed memory of all the night swe have seen. When you replay the memory in your mind you remember the unique details, and the background is filled in from averaged memories.
Most people never even see really dark night skies. It is estimated that over 80% of all people have never seen the Milky Way. So most people never even experience truly dark skies. Most people see night skies in light polluted places or with a moon in the sky, both of which make the sky lighter and bluer. The moon is above us more often than not, and lightens the sky, and that is what we mostly remember, a dark slightly bluish sky.
When I first started out I thought the darkest night skies would be black. When I got to the really dark places, it was not black. Now I see photos with black skies and they do not look real to me. The night sky also never looks brown to me but in fact the sky can have warm tones. The sky mostly looks “dark” in away that is hard to explain. To my eyes, the darkest skies look like a very dark, very desaturated navy blue, for lack of a better description.
Another question is just what can people identify with? I have processed these images in many different ways. When you make the Milky Way warmer and yellowish brown the background sky, especially near the horizon frequently turns brownish. This can be true to physics but it can look unnatural.
Adding to the confusion is that the camera sees many more colors than our eyes. These are frequently wildly beautiful. Airglow, and light pollution can create colors we never dreamed were present.
So what do you do? Do we try to reproduce what we see, or what the camera sees, or what physics sees? Well, the answer in photo circles seems to be you do just about anything you want. Once I got in a discussion with a respected photographer about the color of the sky. At that time I was arguing sky should be a warmer color. I finally asked “ so what color is the night sky”? His answer was “any color I want it to be”. That answer bothered me at first, but now I see that it holds a lot of wisdom.
Do you want to make a photo that is true to physics, true to your eyes, or simply try to make a work of art? Since there is no general agreement, it is a question each person has to answer for themselves. That's what makes it so interesting, a freedom of expression that does not exist in many other realms of photography.