A lamp assembly particularly for a luminaire comprising a lamp having a light emitting member of generally torroidal shape and a reflector positioned and shaped to reflect light received from the light emitting member through the central opening. The light emitting member is preferably a filament of an incandescent lamp. The reflector has a cross-section comprising first and second arcs which are substantially symmetrical with respect to a line joining the center of the reflector and a point substantially at the centre of the torroidal member and the shape of the reflector is that described by rotating said arcs about said line. The arcs may be elliptical or circular for example with their foci or centers positioned to achieve the required effect.