HDR SkiesHDR environment maps created entirely in Blender
They’re really not hard to create! It just takes very long to render volumetrics.
All of these were eyeballed with one lighting reference so their physical accuracy is questionable at best.
old.exr is an old HDR sky from September 2018. It uses the old Volume Scatter shader for the atmosphere. The camera is located on the surface of a sphere inside the atmosphere. Note how both the sun and surface could use a subdivision surface modifier.
Due to the fact that indirect lighting was actually a huge pain to render with volumetrics in a reasonable amount of samples, this setup does not actually use the white sphere for lighting, but instead a regular point light inside the sphere.
nebula_sky.exr is a whole lot of star particles plus some texture painting with noise to create some sort of stylized night sky.
Daylight Cycle Series
These environments are all the same except for the position of the sun, and background brightness.
The setup uses nebula_sky as the world background, the same sun as in the old setup, and a Principled Volume shader with a light blue base color and an orange absorption color as an atmosphere.
Note that the sun might be a little too close for proper sharp shadows.
night.exr (note the preview image above has +5 exposure)
twilight.exr (note the preview image above has +5 exposure)
dawn_unadjusted.exr (note that the stars are maybe too bright)
dawn.exr (fixed star brightness)