the top scene is lit by two area lights, one in the middle of the room the other right behind the left sphere. Render time was 18 hours, mostly due to caustics. Global illumination can be seen in the color bleeding across the walls.

The bottom scene is lit by two area lights. one backlighting the spheres, the other front lighting them. A procedural texture is applied to the foremost sphere. Global illumination was used two create the color bleeding on the reflective ground.