It says in the manual that even though ambient occlusion is just an approximation and faster than the option Full Indirect Lighting, it renders a more realistic light. I never really tried to figure out the concept of indirect lighting until now so just too what happended, I flicked on the ambient occlusion with the fedault settins and rendered my scene.

I couldn't really see any difference at all. I loaded various scenes and tried the same thing, still no visible difference in my renders. So I increased the ambient occlusion radius to 8 and tried again. Well, darker areas got even darker but not really something I've would have noticed if I didn't know to look for a difference. I cranked it up 25, yet again the darker areas got even darker and perhaps now there was a difference anyone could see. But darker areas? That's it? I could have made that postwork in two seconds in Photoshop.

So I was wondering, when does ambient occlusion take effect? Do I have to flick on sky lighting for it to be meaningful? Or put it this way, if I only have the basic default ambient light (set at 20%) and let's say two spotlights, will ambient occlusion make any sort of differences worth speaking of? Or is the ambient occlusion close connected to sky light and atmosphere?

Basically, how do I take advantage of ambient occlusion in Carrara? I just had big expectations when they started talking about realistic light and ambient occlusion in the manual. What should I think about when I set up lighting? Do I have to crank up the ambient light first?