>>My main aim is to master radiosity so I can slowly replace Lightscape<< Have you looked at Mental Ray, Angela? It seems a bit more forgiving of modeling issues. MR still has a steep learning curve to make it productive and doesn't have any tools to measure light quantity (not that that has any bearing on the image in radiosity), but it seems to be where things are headed. It's not where I'm headed right now though, I'll leave that to others! :) Good luck Ted