There are 18 red LEDs in the main observatory (6 each on West, North & East walls) and another 6 in the Control room. They are all controlled from a control box that provides variable brightness control. The electronic control circuitry was designed and installed by Anthony Lewis (of Lewistronics fame). The LEDs were ground flat on their tips to provide more spread / diffusion of the red light. They are mounted about 800mm off the floor, and provide illumination of the floor / wall boundaries without a direct view of the LEDs themselves.