1923: In parallel to the works on the projector, a dome of 16 meters was raised on the roof of the Zeiss Company in Jena. After 4 years of planning and constructing the planetarium was complete. In August 1923, an artificial sky flashed up for the first time ever. Two months later, the projector was brought to Munich for a presentation in the Deutsches Museum. There, a 9.8 meter provisonal dome of gypsum had been prepared. Walther Bauersfeld performed the first astronomical show at the annual general meeting on October 23rd, 1923. A few weeks of public presentations followed. Then, the projector returned to Jena for a final completion. Its ultimate place, the projector found in the newly built 10-meter dome in May 1925.

Of this model, which was later termed "Model-I", two instuments were manufactured. The second had some small improvements like little variation in latitude and it projected circles for the meridian and ecliptic. It was intended as a trial, but then delivered to Dusseldorf, because the requests for the devices rose faster than the company was able to construct. Munich's Model-I operated until 1951, then it moved into another dome but in the same building. In 1960, it was replaced against a newer model. Now, it can be viewed as an exhibit of the museum.