While spending a winter season in the mountains, I came to observe the evening sky a lot.
Daylight, from sunrise to sunset, is composed out of three primary colors which can be perceived by a human eye. Red, green and blue are fading from the first to the last sunbeam over the open sky. Our human eye can not always differ them one from each other, as daylight is a complexe mixture by the three of them.
However, there are light phenomenon where we can perceive them precisely, like in a rainbow or the simple reflection of red light on a mountain face while sun is setting. Those phenomenon can by explained by the refraction of light, once our sunbeam goes from one physical environment to another. This happens when sunlight enters our atmosphere.
I observed, that some time after sunset but before nightfall, all the three primary colors of the light spectrum are fading over the sky within more or less 45min. I‘m talking about the last sunbeams which are caressing our hemisphere just before giving birth to a new day on the other hemisphere.
So I tried to catch this phenomenon on film....
...and was surprised how nicely it worked out.
These photographs have absolute no photoshop color correction. Just adapting curves while scanning and dust off.