Planetarium projector

[1] This model of Zeiss projector was a 13-foot (4.0 m)-long dumbbell-shaped object, with 29-inch (740 mm)-diameter spheres attached at each end representing the night sky for the northern and southern hemispheres.

Connecting the two spheres was a framework that held nearly 150 individual projectors, including those dedicated to the planets, the Sun, and specific stars.

Twenty-three of the most prominent stars had their own projectors, designed to project a small disk instead of pinpoint of light, and were also colored: Betelgeuse and Antares would appear reddish, Rigel and Spica would each have a blue tinge.

In more recent years, planetaria — or dome theaters — have broadened their offerings to include wide-screen or "wraparound" films, fulldome video, and laser shows that combine music with laser-drawn patterns.

The newest generation of planetariums such as Evans & Sutherland's Digistar 7, Global Immersion's Fidelity or Sky-Skan's DigitalSky Dark Matter, offer a fully digital projection system, in which a single projector with a fish eye lens, or a system of digital video or laser video projectors around the edge of the dome, are used to create any scene provided to it from a computer.