After German reunification in 1990, Jena was seeded into the 2. Bundesliga . Their second-place finish in 1992 deteriorated into a 17th-place finish in 1994 and relegation to Regionalliga Nordost (III). They won immediate re-promotion, and played for three more years at the tier-II level. Since 1999 the team has primarily played tier III and IV football, but a second place-finish in the Regionalliga Nord secured Jena promotion to the 2. Bundesliga for the 2006–07 season. Jena remained in the 2. Bundesliga in 2007–08 , avoiding relegation by winning 2–1 away against FC Augsburg in their final match of the season. They would finish last in the 2. Bundesliga in 2007–08, returning to the third tier. However, this would not be one of the Regionalligen; the German Football Association (DFB) launched the new 3. Liga for 2008–09, of which Jena was a charter member. On 9 November 2009 Chairman Peter Schreiber announced his retirement;  on 13 November the executive board accepted his resignation,  and on 25 November Hartmut Bayer became the new chairman.  The second team was involved in the 2009 European football betting scandal ,  accused of match-fixing in the game against ZFC Meuselwitz .  On 10 December 2009 the club announced that it was in financial distress, owing over €1 million.  In January 2010 the players agreed to accept a lower salary.  Carl Zeiss Jena have a friendship with Welsh side Newport County, after the two sides played against each other in the European Cup Winners Cup in the early 1980s. As with Carl Zeiss Jena, Newport County have seen similar struggles off and on the pitch, and both teams regularly play each other during pre-season.
From its introduction in 1932 to 1936 when the Contax II was introduced, the Contax I was a work in progress. There are no fewer than six iterations based on external features only. This is actually an underestimate. There were also many non-visible internal changes such as the location and physical layout of how the angular displacement of the lens couples to the rangefinder system. Other changes were meant to make the rangefinder system stay within specifications better. Later versions actually provide better focusing feedback to the user. These were not small changes, and many of the still-working models are actually later revisions. These revisions were incorporated in the Contax II, a much more reliable camera that went through fewer versions.
The communist German Democratic Republic was established in the historic "Mitteldeutschland" ( Middle Germany ). Former German territories east of the Oder and Neisse rivers, mainly the Prussian provinces of Pomerania , East Prussia , West Prussia , Upper Silesia , Lower Silesia , the eastern Neumark of Brandenburg , and a small piece of Saxony were thus detached from Germany. To compensate Poland for the USSR's annexation of its eastern provinces, the Allies provisionally established Poland's post-war western border at the Oder–Neisse line at the Yalta Conference (1945). As a result, most of Germany's central territories became the Sowjetische Besatzungszone (SBZ, Soviet Occupation Zone). All other lands east of the Oder–Neisse line were put under Polish administration, with the exception of historic northern East Prussia , which went to the USSR.