 Continuous , short @-@ arc , high pressure xenon arc lamps have a color temperature closely approximating noon sunlight and are used in solar simulators . That is , the chromaticity of these lamps closely approximates a heated black body radiator that has a temperature close to that observed from the Sun . After they were first introduced during the 1940s , these lamps began replacing the shorter @-@ lived carbon arc lamps in movie projectors . They are employed in typical 35mm , IMAX and the new digital projectors film projection systems , automotive HID headlights , high @-@ end " tactical " flashlights and other specialized uses . These arc lamps are an excellent source of short wavelength ultraviolet radiation and they have intense emissions in the near infrared , which is used in some night vision systems . 
