The motion detector recognises whether someone enters a dark room or leaves an illuminated room. In the first case, it activates the light with the brightness and colour temperature you have programmed. So if, for example, the children have to go to the loo at night, they are not dazzled by bright light but are guided through the corridors by soft lighting. In the second case, when someone leaves a room and no one is moving around, the sensor first gradually dims the light by 50 per cent before switching it off completely.