Image1: 3 spheres (diffuse, specular, specular+refractive) in a box with coloured walls. lighting is received from a sphere light (note the soft shadows).
Image 2: 9 spheres (3 diffuse, 6 highly specular) in a box with gray specular + light-diffuse. Features a very high number of reflections. The black line in the center is because rays hitting the exact corner. (a little offset should have removed that, however the image took 7 hour to generat so i left it this way).
Image 3: several cylinders in a box with coloured walls. Contains 4 spheres (3 shiny, 1 diffuse). Columns + walls are diffuse. This image presents the ability to move objects (columns)