In the context of indexing of video data bases, the future standard MPEG-7 will provide descriptors for motion, shape, texture and color to characterize and identify video scenes. This report presents a descriptor, which has been proposed to MPEG-7 recently, for effects caused by the scene illuminatio- n. The proposed descriptor addresses temporal changes of object shading, of cast shadows and of the global illumination intensity by one single scalar. It is based on temporal changes of image luminance along motion trajectories. Further, an automatic, noise adaptive method for the extraction of the illumination effect descriptor from a video sequence is presented. A performance analysis and sample retrieval experiments show that extracted descriptor values are sufficiently precise and sensible to distinguish video sequences with different scene illumination.