Also, if you turn on Gamma correction it helps. The manual says the Gi takes into account the gamma adjustment. I am testing that now. I am rendering some without gamma and then with gamma. Then I am going to adjust gamma in post on the non-adjusted render and see if I can match the Carrara adjusted image. If so, then the gamma correction is just that, simple gamma. If not, then it truly does take into account the gamma when calculating the GI. I know I get a lot cleaner renders with it on. It is much easier to set it in Carrara. Otherwise I have to render, then adjust it to see if is right. I prefer doing it in Carrara and it doesnt add much to the render time.