Abstract: A guidance light including an optical system comprising a reflector having an internal concave reflecting surface formed as a surface of revolution about the optical axis. Said reflecting surface is configured so as to reflect the light from a light source onto said axis along a continuous segment thereof such that each point reflects light onto said segment at a distance from its end nearest to the light source which is proportional to the arcuate length of the reflecting surface between said point and the intersection of said surface and said axis. Exit optical means are also included to redirect the light beam in the suitable direction.