A luminaire (61) is disclosed with a close coupled ballast (62) having a support arm (66) from which is suspended or hung a reflector, and preferably a variable focus reflector (41), having either a single ended lamp (3) or double ended lamp (23). The luminaire (61) is supported from a greenhouse rafter (9) by filaments (10, 11) which are connected one to the ballast (62) and the other to the free end of the support arm (66). In one embodiment the arm (66) is connected to a rigid side plate (64) which is mounted on the ballast (62). In another embodiment the arm (66) is connected to a side plate (164) which is hinged. The arrangement enables flimsy reflectors (41) to be close coupled with electronic ballasts in a way which minimises Radio Frequency Interference (RFI).
