A lighting system is provided that has lighting units and sensor units. One of the sensor units is first sensor unit that comprises a user control device for receiving user commands when a user enters the commands at the user control device. The lighting units are controlled according to a lighting plan that defines a group of the lighting units that is to be switched on in response to detection of a user command at the user control device, based on light transfer coefficients relating light intensities at the sensor units to light output from the lighting units. The transfer coefficients from the lighting units to each sensor unit are determined. The lighting plan is determined from the transfer coefficients by selecting the group of lighting units based on the transfer coefficients from the lighting units to the first sensor unit. The transfer coefficients from the lighting units to a sub-set of the sensor units may be used, the sub-set being selected for the first sensor unit, based on the transfer coefficients for the sensor units from an initial group of one or more of the lighting units associated with the first sensor unit.