Rather than wasting sunlight on the roofs of movie theaters, the sun can be used as the light source for theater projectors.

The roof of the theater is fitted with a heliostat inside a cylindrical skylight.  A mirror in the center of the skylight is mounted on a motor’s shaft that is aligned with the Earth’s rotational axis (at the latitude of the theater*) which turns to track the sun.

The rotating mirror is tipped at an angle to reflect sunlight onto stationary mirrors on the axis of the projector, through the film and lens, and onto the screen.  Conventional theaters use expensive, short-life 3-4 KW Xenon projection lamps.  It would be a missed opportunity to not use the sunlight when available.  During cloudy periods and at night, a conventional lamp can be moved into the light path.