I meant to mention in my last post, that I'd made a mistake in describing the tweaking in my 'Cornel Box' pic. When I went back into the file to explore a bit more, I noticed that all my settings were actually consistent. It was in the journey to that file that I'd messed about with all the settings; rotated primitives; and tried meshes instead of primitives; and all sorts. The 'fix' in that image is the use of a large ambient/diffuse light source behind the camera to add to the illumination in the scene. This is providing more light than just another plane wall would. The consistent settings I used were wrong, though. I used too much ambience. At that stage I was using 100 percent, but nowadays I use less. Going back to Len's images, I have a concern with the second one. The sphere has transparent and reflective attributes. This may be deliberate, but it happens to also look exactly like the problem I was having with transparent objects picking up a weird reflective attribute even when no such setting was applied. I'd like to see an image something like the one I attempted showing one purely reflective sphere beside one purely transparent sphere. And I'd also like to see a render of an organic mesh model under PRO-RENDER settings to demonstrate how mesh smoothing looks. And speaking of meshes, I've been surprised at how many look bad under True Ambience. Many surfaces render black. What the hell, now I'm in request mode, I'd like to see a PRO-RENDER of a Bryce primitive boolean interaction. One of the default ones from the library should indicate whether PRO-RENDER has overcome the nasty experience I had with booleans under True Ambience.