Abstract: A method, configuration unit (100), and control unit (160) for configuring a lighting system (101) with respect to light other than light emitted from an illumination device (103) are provided. The lighting system comprises the at least one illumination device arranged in an illumination plane (104) to illuminate a workspace plane (110). The method comprises the step of obtaining a first contribution of the light other than the light emitted from the illumination device at a first location (113) in the illumination plane based on a first signal representative of a total light intensity measured at the first location. Furthermore, the method comprises the step of obtaining a second contribution of the light other than the light emitted from the illumination device at a second location (121) in the workspace plane based on a second signal representative of a total light intensity measured at the second location.