A headlight for a motor vehicle, in order to provide a cut-off light beam, comprising: a collector mirror of an ellipsoidal type with an optical axis; a source of light (S) placed in the vicinity of the inner focal point of the collector mirror; a substantially flat bender, the reflective surface of which is oriented towards the interior of the collector mirror, and has an edge which is situated in the vicinity of the other focal point of the collector mirror, and a lens, situated to the front of the collector mirror and the bender, in order to provide an image of the edge of the bender.