With ceiling illumination, either light is shone to illuminate the ceiling in its own right or the ceiling is merely used as a reflector for general lighting. The ceiling is primarily emphasised, when it has an intrinsic communicative value, e.g. due to architectonic structures. Illuminating the ceiling to provide indirect general lighting requires it has a high reflectance. It should be noted the ceiling will then be the brightest surface in the room and will therefore be emphasised.