Wikipedia
Pentacon
Pentacon is the company name of a camera manufacturer in Dresden, Germany.
The name Pentacon is derived from the brand Contax of Zeiss Ikon Kamerawerke in Dresden and Pentagon, as a Pentaprism for Single-Lens Reflex (SLR) cameras was for the first time developed in Dresden. The cross section of this prism has a pentagonal shape. Pentacon is best known for producing the SLR cameras of the Praktica-series as well as the medium format camera Pentacon Six, the Pentacon Super and various cameras of the Exa series.
Pentacon also produced slide projectors.