Abstract: This invention relates to a light regulating system comprising a rail, a plurality of lamellae, lamellae support members, a lamellae rotating actuator system, a measurement system, a detector, and a control unit, wherein an operating member is connected to the lamellae rotating actuator system to allow rotation of the lamellae by manual operation of the operating member, and wherein the control unit is configured to operate in a main automatic mode in which the lamellae rotating actuator system is autonomously driven, provided that the detector indicates that the lamellae support members are in a closed position and there is no indication from the measurement system that the lamellae have been rotated by a user.