Device for light emission with a) at least three light sources (2 1, 2 2, 2 3), b) means (3 1, 3 2, 3 3) for powering the light sources (2 1, 2 2, 2 3), c) a sensor for detecting a measurement signal that corresponds to the light emitted from the light sources (2 1, 2 2, 2 3) in its entirety, and d) a control unit for controlling the means (3 1, 3 2, 3 3) for powering the light sources (2 1, 2 2, 2 3), wherein the control unit is designed to, - so control the means (3 1, 3 2, 3 3) for the power supply in a calibration phase that a measuring signal (S1, S2, S3) is respectively detected in a sequence of at least three measurement periods by the sensor, wherein the light emitted from the light sources (S1, S2, S3) is reproduced in each measuring period and the individual brightness (L1, L2, L3) of each individual light source (2 1, 2 2, 2 3)is calculated on the basis of the measuring signals (S1, S2, S3) detected by the sensor, wherein each of the measurement signals (S1, S2, 33) of a plurality of the light sources (2 1, 2 2, 2 3) detected by the sensor originates in at least one of the measurement periods, wherein the light emission of each light emitting light source (2 1, 2 2, 2 3) remains constant in each measurement period, and wherein the light emitted from the respective light sources corresponds in its entirety to various combinations of light emissions from the light sources (2 1, 2 2, 2 3) in the various measurement periods, and wherein the control unit is designed to so control the means (3 1, 3 2, 3 3) for the power supply, - that exactly one of at least three light sources (2 1, 2 2, 2 3) is dimmed to a level in each measurement period of the at least three measurement periods, or - that the at least three light sources (2 1, 2 2, 2 3) are dimmed to a level in such a way in the at least three measurement periods, that - none of the at least three light sources (2 1, 2 2, 2 3) is dimmed to the level in a first measurement period, - a first light source of the at least three light sources (2 1, 2 2, 2 3) is dimmed to the level in a second measurement period, and - the first light source and a second light source of the at least three light sources (2 1, 2 2, 2 3) are dimmed to the level in a third measurement period, characterized in that, this level lies below a threshold value that is detectable by the sensor. a) at least three light sources (2 1, 2 2, 2 3), b) means (3 1, 3 2, 3 3) for powering the light sources (2 1, 2 2, 2 3), c) a sensor for detecting a measurement signal that corresponds to the light emitted from the light sources (2 1, 2 2, 2 3) in its entirety, and d) a control unit for controlling the means (3 1, 3 2, 3 3) for powering the light sources (2 1, 2 2, 2 3), - so control the means (3 1, 3 2, 3 3) for the power supply in a calibration phase that a measuring signal (S1, S2, S3) is respectively detected in a sequence of at least three measurement periods by the sensor, wherein the light emitted from the light sources (S1, S2, S3) is reproduced in each measuring period and the individual brightness (L1, L2, L3) of each individual light source (2 1, 2 2, 2 3)is calculated on the basis of the measuring signals (S1, S2, S3) detected by the sensor, - that exactly one of at least three light sources (2 1, 2 2, 2 3) is dimmed to a level in each measurement period of the at least three measurement periods, or - that the at least three light sources (2 1, 2 2, 2 3) are dimmed to a level in such a way in the at least three measurement periods, that - none of the at least three light sources (2 1, 2 2, 2 3) is dimmed to the level in a first measurement period, - a first light source of the at least three light sources (2 1, 2 2, 2 3) is dimmed to the level in a second measurement period, and - the first light source and a second light source of the at least three light sources (2 1, 2 2, 2 3) are dimmed to the level in a third measurement period,