Many European cameras from the period from World War I to World War II were manufactured in camera-assembly plants in a number of countries. Many of these cameras were equipped with Zeiss lenses, all of which are serial numbered.
This chart, covering the years from 1912 up to World War II, provides the basis for rough-dating of a camera to within a year of its production.
Serial Numbers of Zeiss Lenses by Year of Manufacture
