A luminaire comprising an output aperture having an input port and an output port, a radiation guide having an input port and an output port and an array of LEDs located at the input port of the guide. Light emitted by the LEDs is transmitted into the guide. The input port of the aperture operatively connects to the output port of guide and is positioned adjacent thereto so that a central plane of the output aperture is asymmetric relative to a central plane of the radiation guide.