A planetarium projector is a device used to project images of celestial objects onto the dome in a planetarium. A planetarium is a theater built primarily for presenting educational and entertaining shows about astronomy and the night sky, or for training in celestial navigation. ...

The first modern planetarium projectors were designed and built by Carl Zeiss in 1924 Germany, and have grown more complex. Smaller projectors include a set of fixed stars, Sun, Moon, and planets, and various nebulae. Larger machines also include comets and a far greater selection of stars. Additional projectors can be added to show twilight around the outside of the screen (complete with city or country scenes) as well as the Milky Way. Still others add coordinate lines and constellations, photographic slides, laser displays, and other images. The OmniMax movie system (now known as IMAX Dome) was originally designed to operate on planetarium screens. Carl Zeiss Carl Zeiss (September 11, 1816 – December 3, 1888) was an optician commonly known for the company he founded, Zeiss. ... 1924 (MCMXXIV) was a leap year starting on Tuesday (link will take you to calendar). ... The Triangulum Emission Nebula NGC 604 lies in a spiral arm of Galaxy M33, 2. ... Comet Hale-Bopp For other uses, see Comet (disambiguation). ... Note: This article contains special characters. ... Orion is a remarkable constellation, visible from most places on the globe at one time or another during the year. ... Lasers range in size from microscopic diode lasers (top) with numerous applications, to football field sized neodymium glass lasers (bottom) used for inertial confinement fusion, nuclear weapons research and other physics experiments. ... IMAX (for Image Maximum) is a film projection system which has the capacity to display images of far greater size and resolution than conventional film display systems. ... Film refers to the celluloid media on which movies are printed. ...

1960s

Zeiss-Jena Universal Projection Planetarium Type 23/6 1 - Constellation Figure Projector (North) 2 - Star Globe (North) 3 - Mechanical shutter of star field projector 4 - Milky Way projector (North) 5 - Planetary projectors (North) 6 - Lattice ring for Sun, Moon and Vertical circle projectors 7 - Horizon circle projector 8 - Planetary projectors (South) 9 - Star Globe (South) 10 - Compass point projector

A good example of a "typical" planetarium projector of the 1960s was the Universal Projection Planetarium type 23/6, made by Kombinat VEB Carl Zeiss JENA in what was then East Germany^{[JenaMagazine]}. The planetarium projector was a 13-foot-long dumbbell-shaped object, with 29-inch-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. The Volkseigener Betrieb (German: people-owned enterprise; abbreviation: VEB) was the legal form of industrial enterprise in East Germany. ... Carl Zeiss Carl Zeiss (September 11, 1816 – December 3, 1888) was an optician commonly known for the company he founded, Zeiss. ... National motto: none Official languages German Capital East Berlin Largest city East Berlin Area  - Total  - % water Ranked 106th 108,333 km² Negligible Creation -Abolition 7 October 1949 3 October 1990 Currency East German mark Time zone  â€“ in summer CET (UTC+1) CEST (UTC+2) National anthem Auferstanden aus Ruinen Internet...

Each globe held representations of almost 4,500 stars per hemisphere. The "stars" were created by tiny holes that were punched into copper foil, ranging from 0.023 to 0.452 mm in size, the larger holes letting more light get through and thereby creating brighter star images. Two glass plates held this foil between them to create what was called a "star field plate". Each globe was illuminated using a 1,500-watt lamp that was located in its center. A number of aspherical condenser lenses were placed within each globe to focus the light onto the plates. 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 redish, Rigel and Spica would each have a blue tinge. An image of the Milky Way was created by using drum-type projectors that were studded with unfocused pinprick-sized holes based on photographic images of our galaxy. Specific projectors could imitate the light changes of such variable stars as Algol or Omicron Ceti, and other projectors could produce images of the constellations, of specific historical comets, compass points and other astronomical phenomena. When a particular star or planet dipped below the artificial horizon, a gravity-based mercury-filled shutter would be activated, blocking out the light. Hubble UV picture of Betelgeuse. ... This article is about the star. ... Rigel (pronounced ) (β Orionis) is the brightest star in the constellation Orion and the seventh brightest star in the sky, with visual magnitude 0. ... Spica (α Vir / α Virginis / Alpha Virginis) is the brightest star in the constellation Virgo, and one of the brightest stars in the nighttime sky. ... Note: This article contains special characters. ... Most stars are of nearly constant luminosity. ... ALGOL (short for ALGOrithmic Language) is a family of imperative computer programming languages originally developed in the mid 1950s which became the de facto standard way to report algorithms in print for almost the next 30 years. ... Orion is a remarkable constellation, visible from most places on the globe (but not always the whole year long). ... Comet Hale-Bopp For other uses, see Comet (disambiguation). ... A compass rose showing the cardinal directions Cardinal directions or cardinal points are the four principal directions or points of the compass in plane. ... Horizon The horizon is the line that separates earth from sky. ... General Name, Symbol, Number mercury, Hg, 80 Chemical series transition metals Group, Period, Block 12, 6, d Appearance silvery white Atomic mass 200. ...

Recent developments in planetarium projectors technology

In recent years, planetariums — or dome theaters — have broadened their offerings to include wide-screen or "wraparound" films, all-sky video, and laser shows that combine music with laser-drawn patterns. The newest generation of planetariums such as Evans & Sutherland's Digistar 3 or Sky-Skan's DigitalSky, offer a fully digital projection system, in which a single large 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. This gives the operator tremendous flexibility in showing not only the modern night sky as visible from Earth, but any other image they wish (including the night sky as visible from points far distant in space and time). Evans & Sutherland is a computer firm involved in the computer graphics field. ... Digistar 3 is a dome-based projection technology created by Evans & Sutherland to offer audiences immersive entertainment and education experiences that integrate all-dome video, real time 3D computer graphics, and a digital planetarium facility. ... A digital system is one that uses numbers, especially binary numbers, for input, processing, transmission, storage, or display, rather than a continuous spectrum of values (an analog system) or non-numeric symbols such as letters or icons. ... Earth is the third planet from the Sun. ...