A foldable reflector screen includes a flexible, cloth-like reflective element having an inside and an outside, a supporting and tensioning structure arranged to support the reflective element on the outside, and a carrier element including at least one lamp and mounting the supporting and tensioning structure. The reflector screen has an open state in which the reflective element forms an essentially rotationally symmetrical body having an axis of rotation and has a light outlet opening. The reflective element comprises at least two reflective sections. The two reflective sections have in each case a different geometrical shape in a section containing the axis of rotation of the reflective element.