Are Jena Zeiss, Carl Zeiss, and Zeiss Ecolab the same company?

Carl Zeiss AG was a German company that manufactured optical systems, industrial measuring instruments and medical equipment. As a result of World War II, this company was split into two companies - Carl Zeiss AG and VEB Carl Zeiss Jena - for a time until it was re-merged in 1990.

In 1926, Zeiss merged four German camera manufacturers to form Zeiss Ikon AG. Zeiss Ikon produced Contax cameras in the early days. It became a subsidiary of Carl Zeiss AG after the division of Germany, and then merged with Freunda in 1969.