Thanks for the comments but I did have a specific idea in mind I thought GI would be good for. That's why I bought C2 in the first place. However as you can see from the streaks in this test render it seems Carrara is unable to cope with global illumination. Eovia reports that this is yet another bug in the renderer which "they will fix in a future release". Yeah and charge me another few hundred dollars. I've sent them 2 bug reports in as many weeks they should be paying me. Quirky programs are the name of the game but if in the end you can't produce then it's all just a waste of time. Feeling peevish... ED