Zeiss projector

[1] The first modern planetarium projectors were designed and built in 1924 by the Zeiss Works of Jena, Germany.

[2] Zeiss projectors are designed to sit in the middle of a dark, dome-covered room and project an accurate image of the stars and other astronomical objects on the dome.

[3] It possessed a distinctive appearance, with a single sphere of projection lenses supported above a large, angled "planet cage".

Beginning with Mark VII, the central axis was eliminated and the two spheres were merged into a single, egg-shaped projection unit.

[4] The Mark VII was developed in 1993 and was the first joint project of the two Zeiss factories following German reunification.

The Mark I projector installed in the Deutsches Museum in 1923 was the world's first planetarium projector.
The Mark III modified projector installed in the Planetario Humboldt 1950 in Caracas - Venezuela.It is the oldest in Latin America.
Marks II through VI utilized two small spheres of lenses separated along a central axis.
Beginning with Mark VII, Zeiss projectors adopted a new, egg-shaped design.
The Mark IX Universarium is currently the most advanced model. This example was installed in 2006 at The Griffith Observatory in Los Angeles.
Closeup of a lens bearing sphere of the Zeiss Mark IV planetarium projector on display at the Nehru Planetarium in Mumbai, India.