I have been trying a few ways to get these really intense atmospheric gradients I see in night photos sometimes without much success. It kind of looks like in this one there are maybe a couple cities in the background providing this beautiful orange-ish glow:
https://ychef.files.bbci.co.uk/976x549/p0blm65q.jpg
I tried to reproduce this by setting up a night scene and placing a generic light source with a really high strength in the background. Tried with and without the "glow in atmosphere and clouds" box ticked.
I attached the best I've been able to achieve so far. There is a "city" on the right of this image, and it does give an ok atmospheric glow, but its not very intense. In the photo above, the gradient is a very rich color that is different from the rest of the sky, and also it dies off completely a pretty short distance from the light source. I can't seem to change the color much in mine from the whitish blue I have or it just looks like a weird dull version of the color I chose without having any nice brilliance or "glow" factor. Also if I increase the light strength, my gradient extends too far outward and doesn't die off like the photo. Any tips on achieving something like this?
This example is over exposure. So you need to up your contrast and probably exposure in the camera. A haze layer close to the ground to capture light as well would help. High scalar value for direct light modulator, most likely (since it's a darker scene and just want the glow). Adjust sun glow amount on the haze layer will spread the glow captured from the sun.
The only issue with this approach, is the lighting glow is from exposure, of a camera, which TG just can't do. So the shadows from the terrain which are mainly gone in a over exposure, are very prominent in TG. To try and defeat those horizon shadows, you may want to mask the scene to around 0,0,0.
If you are using the standard renderer you can also up the strength of surfaces lighting in the enviro light shader.
I've got exposure cranked up to 40 for my image, I guess I could try like reducing the star luminance and cranking it even more. When you say "up your contrast", is that a setting somewhere I should tweak? I'm going to need to study up on the haze stuff I guess, there is a lot there I still don't understand. Are you saying I should add a new haze layer, or lower the one in my existing atmosphere node?
You need to capture that light below the horizon with some haze that has higher lighting settings too. Strength on surfaces in Enviro Light will help getting light on the terrain too.
It does seem you are looking high into the sky though, where this effect wouldn't really exist.
"you are looking high into the sky though"
Hmm, this is a good point. Now that I look again most of the photos I'm seeing with this affect do have it happening on a fairly flat horizon. I'm going to do some searching/experimenting later...
Here is a quick example doodle.
Wow controlling the glow with a cloud layer like that is genius. Thank you!