Dependence of the optical light leak on the Sun direction: SRG is located at the center of a sphere, which illustrates the orientation of its principle axes (SRG_ X, SRG_ Y, SRG_ Z). The circular map on this sphere shows how the observed event rate in TM5 depends on the Sun direction. This map covers the full range of angles between Sun direction and SRG Z axis. This map, which was derived from all-sky survey data, indicates that sunlight enters primarily from the lower right. The camera platform at the bottom shows where TM5 is located.