Abstract: A low pressure metal or metal halide vapor lamp for photocopying applications. The low pressure sodium vapor lamp is operated in a continuous mode and provides illumination of increased brightness and of a color (yellow) which is optimum for providing a copy which is an accurate representation of the original. An auxiliary heater is formed on the lamp to both decrease the warm-up time of the lamp and to control lamp temperature for optimum light output, an electrical control circuit being coupled to the heater to control the current therethrough.