The Amazing Wall Shadow Clock by Time Vision Back in the day we used the shadows to tell time. By watching the sun elongate the tree shadows on the ground to using sundials to pinpoint the precise minute, shadows have been helping us keep track of our days forever. The wall shallow clock uses shadows and the entire wall to illuminate the time. No face or numbers only the simple interplay of shadow and light. A conventional light bulb and clock movement are all it takes to bring this amazing concept to life.