Headlight for a motor vehicle which generates a partial main beam light distribution with the aid of a reflection system

The headlight (10) has a light module (12) having a reflector (14) and a semiconductor light source (16). The reflector reflects the incident light from the semiconductor light source along a main radiation direction (X), so as to generate light distribution having linearly extending light-dark boundary. The semiconductor light source is arranged such that the longitudinal sides of light emission surface in the main radiation direction are oriented transversely to the main radiation direction and rectilinear light-dark border.