Ice-boy - some things to think about:
- Simulating a photo would also entail simulating the white balance selected by the photographer. What I'm getting at is that if I have my photo white balance adjusted in various ways, the same photo can be blue or orange or neutral. I once made a few test photographs (not a render) of snow at night lit only by a sodium vapor lamp. Sodium vapor produces a very distinctive orange light. In one photo I left the white balance on "auto" (let the camera decide) and the snow was orange, like the fruit. Then I manually adjusted the white balance for the colors actually being produced, and the snow was white as ... snow. Same scene, same light, totally different outcome. What are you trying to achieve? I can get blue or orange shadows in a photo from the same real-life setup.
- Depending on conditions, the direct illumination from the sun can be anywhere from 4 to 10 times brighter than the ambient illumination from the sky, and as much as 100 times the ambient illumination from the local environment. Which scenario are you working on? For example, in one of my recent aviation renders, the sky was mostly bright clouds, but some clear blue sky. I built an IBL from my sky panorama and set it to 40% intensity. My sun (infinite) was white at 280% intensity.
It is possible to do the slightly yellow sky, slightly blue IBL thing and then white balance it in post, just like you would with a badly taken photo. This will measure whatever the combination produced for the bright parts and make them neutral, even though you may have started with too much blue or too much yellow. The shadows would be blue in any case.
Personally, I like to assume my "camera" is supposed to be white balancing for the strongest lit things in the scene. So I put a white or very close to white infinite, and a lower intensity blue IBL and it generally comes out right.
Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)
