Lamp apparatus and methods with the illuminant device

The invention has for its object to propose an illuminant device that achieves a predetermined light intensity in a region surrounding the aircraft at the same time a low power consumption. It is proposed an illuminant device 1 which is arranged in a plane to illuminate a surrounding region 2, with at least one light-emitting diode 3, wherein the at least one light emitting diode 3 for illumination of the surrounding region 2 for emitting illumination light (BL formed as a light emitter 3, wherein the at least one light emitting diode 3 for measuring ambient light UL formed as a light acceptor 3b, wherein the illuminant device 1 is formed for generating and maintaining a predetermined light intensity in the surrounding region 2, at least to adjust the illumination light BL of the a light emitting diode 3 to the measured ambient light UL.