Luminaire

A luminaire comprising:

• an elongate reflector extending along an axis and comprising a plurality of elongate facets extending along one another and along said axis, each with a reflecting surface, which facets have a curvature in cross-section;
• an elongate concave counter-reflector extending along said axis such that the reflecting surfaces of the facets and a light emission window of the counter-reflector, which window is situated in a plane T, mutually face one another;
• contact means positioned between the reflector and the counter-reflector for accommodating at least one electric lamp, characterized in that the curvature of a facet n is such that during operation of the electric lamp light coming from the light emission window and incident on each respective facet n is reflected as a beam having a beam angle Φn, a maximum angle of reflection at which light of said beam is reflected being at most equal to αn, wherein αn is an angle of reflection with respect to the plane T at which the light is reflected such that it shears along the counter-reflector.