Arc lights or arc lamps are the general term for a class of lights that produce light by an electric arc from two electrodes, typically made of tungsten and some carbon, which are separated by a gas. The gas contained in the bulb; including neon, argon, xenon, krypton, sodium, metal halide, oxygen and mercury often names the type of lamp. The fluorescent lamp is actually a mercury arc lamp. Most common arc lights for film and video are HMI’s and fluorescent lights.