A remote controller is arranged for selecting a light source among a plurality of light sources. The remote controller has an omnidirectional transmitter and is arranged to instruct, by means of the omnidirectional transmitter, the light sources to transmit a directional signal comprising a code, which is unique for each light source. Further, the remote controller has a directional signal receiver, and is arranged to receive the directional signals from the light sources, and signal comparison circuitry connected with the directional signal receiver. The remote controller is arranged to select one of the light sources on basis of the received directional signals. Furthermore, the remote controller comprises a transmission indicator, which is arranged to generate an indication signal, indicative of a successful omnidirectional transmission, and it is arranged to initiate the selection of one of the light sources by means of the indication signal.