Light & Color

Fluorescent Rods

The UV lamp is run alternating current which goes on-off 120 times per second. your eye doesn't detect this fast flicker, but you do notice its strobe effect. The picture looks interupted because you see the rods only in certain positions, depending on how fast the rod spins when the light flashes on. These many flash pictures persist in your eye, adding up to the "composite" fan.