Illusion with half-silvered mirror.
A single square array of small lights has a full-silvered mirror in back and a half-silvered mirror in front. A long black box placed in back of the infinity mirror appears to have many rows of lights in it until it is removed! ◙◙An interesting sidelight is to use this gizzit to indicate the dynamic range of the eye. Each successive row of lights has an intensity of slightly less than 1/2. Twenty rows of lights can be seen, so the dynamic range of the eye is at least as great as 2^20 or 1,048,576 to 1 (actually greater on the bright side)!