Abstract: A discharge lamp comprises a discharge vessel 20 defining a sealed inner discharge space 22 with two electrodes 24. A filling consists of a rare gas and a metal halide composition and is free of mercury. The discharge vessel 20 comprises outer grooves 36 where the electrodes 24 are embedded, arranged at a groove distance Ra between them. The discharge vessel 20 further comprises an inner diameter ID. In operation of the lamp, an arc discharge is formed between the electrodes and the metal halide composition is partly evaporated. After operation of the lamp, the metal halide composition forms a film on the inner wall of the discharge vessel 20. This film has a surface area AS measured in mm2. The metal halide composition is provided in such an amount within the discharge space 22, that a matching quotient Q, calculated as Q=Ra×ID/AS has a value of 2 or more, such that a high color temperature is achieved.

Abstract: A discharge lamp comprises a discharge vessel 20 defining a sealed inner discharge space 22 with two electrodes 24. A filling consists of a rare gas and a metal halide composition and is free of mercury. The discharge vessel 20 comprises outer grooves 36 where the electrodes 24 are embedded, arranged at a groove distance Ra between them. The discharge vessel 20 further comprises an inner diameter ID. In operation of the lamp, an arc discharge is formed between the electrodes and the metal halide composition is partly evaporated. After operation of the lamp, the metal halide composition forms a film on the inner wall of the discharge vessel 20. This film has a surface area AS measured in mm2. The metal halide composition is provided in such an amount within the discharge space 22, that a matching quotient Q, calculated as Q=Ra×ID/AS has a value of 2 or more, such that a high colour temperature is achieved.

Abstract: The lamp, particularly the high pressure discharge lamp, comprises a socket (10) made of an insulating material, a burner (12) for emitting light mechanically connected to the socket, and a backlead wire (14) connected to the burner (12), wherein the socket (10) comprises a color with a weighted absorption of <50% and/or a ceramic dielectric (16) arranged around the backlead wire (14) is provided, wherein the ceramic dielectric (16) comprises a color with a weighted absorption of <50%. By using colors for the socket (10) and/or the ceramic dielectric (16) with a low absorption it is possible to increase the luminous flux of the lamp significantly without increasing the power of the lamp.