An optical assembly and a luminaire with extreme cutoff beam control optics. The optical assembly includes a base, at least one lens, at least one light emitting diode (LED) positioned to emit light into the lens, and a curved reflector disposed adjacent to the LED. The reflector can be characterized by a first angle between a plane of the base and a first line joining a distal end of the lens furthest laterally from a first end of the reflector and a second end of the reflector located over the lens, and a second angle between the plane of the base and a second line joining a point on the lens located at the optical axis of the LED and the second end of the reflector. The first angle can be between 60° and 90°, and the second angle can be between 70° and 130°.