The Praktisix was manufactured by Kamera Werkstätten (KW). It is a 6×6 SLR modelled on contemporary 35 mm SLRs. It was followed by the Praktisix II and Praktisix IIA, all with minor, relatively cosmetic changes. They all have rather poor reliability, including poor frame spacing.
In 1959 Kamera Werkstätten became VEB Kamera and KinoWerke Dresden. In 1964 they became VEB Pentacon and in 1970, Kombinat VEB Pentacon. With the unification of the East German photographic industry the Praktisix was modified to become the Pentacon Six. Frame spacing was improved through the use of a roller with teeth that is turned by the film as it advances; when the correct length of film has advanced, the mechanism disengages.
When the TTL-metered prism was introduced, the letters 'TL' were added to the name plate but no other changes were made.
The Pentacon Six TLs is a version modified to shoot 4×4.5 cm frames for photo IDs.
The Exakta 66 is based on the Pentacon Six but was made in West Germany by Ihagee Kamerawerk. The body is rubber coated, the film advance lever moves through a shorter angle, and it has a TTL-metered prism coupled to new Schneider lenses.
The Exakta 66 is not to be confused with several earlier cameras with exactly the same name.
A third-party adaptor allows the metered prism from the Kiev 60 (which is based externally on the Pentacon Six) to be attached to most Pentacon Sixes and Exakta 66's. It is brighter, shows more of the view, and is available new. The same adaptor also allows the Kiev 60 waist-level finder to be used. This finder is reportedly inspired by the one found on Rolleiflex TLR cameras and is also better than the original Pentacon finder.