1. A sensor unit for ascertaining control information for use in daylight-dependent light control, comprising: an image sensor for capturing digital image information and a controller for evaluating the image information and generating a brightness signal which represents the daylight, wherein the controller is configured to take into consideration to a greater extent image regions of the image information that is captured by the image sensor which are influenced to a greater extent by the daylight when generating the brightness signal; wherein the controller is configured to independently identify image regions that are influenced to a greater extent by the daylight; wherein for generating the brightness signal, brightness information, in particular brightness values of individual image regions, is/are multiplied by a weighting factor, wherein the controller is configured to independently ascertain the weighting factors for the image regions; wherein the controller is configured to determine the weighting factors for the image regions within the context of an optimization algorithm: wherein the brightness information of two images that have been captured in temporal succession are compared to one another in the context of the optimization algorithm; and wherein, in the context of the optimization algorithm, the controller a) increases the weighting factor associated with an image region if the temporal change in the brightness information of this image region is similar to the temporal change of the overall brightness of the image, b) reduces the weighting factor associated with an image region if the temporal change in the brightness information of this image region is not similar to the temporal change in the overall brightness of the image.