Corrected entry: When Christof touches the huge screen with the image of Truman sleeping, his hand casts a shadow. However, the only light source in the control room is the screen itself. This reveals that the scene was composited using a blue screen.
rabid anarchist
4th Sep 2003
Correction: The screen is not the only light source in the room. There is actually plenty of light in the room. You can even see a bit of light reflecting off Christof's head. In the wide shot of the control room you can see the light for the musician and light illuminating the walls.
Lummie ★