A high-powered source of light produced by means of a discharge between two electrodes. An arc light, for example uses a discharge between two carbon rods which are manually or automatically fed together as they are burnt up. The use of this type of lighting is restricted to non-dimming applications such as followspots and projection, where dimming is achieved by mechanical means. Many of the new generation of moving lights use discharge lamps and dichroic filters. See Ballast, CSI, CID, MSR, HMI, HTI, Xenon, MBI.