The only half-frame Leica model to go into serial production is the Leica 72. It takes 72 instead of 36 exposures on one regular roll of film. Earliest experimental Leica half-frame cameras date back to the 1940s, when film was scarce and valuable. In the early 1950s, a small run of Leica 72 cameras was produced in Wetzlar. The “serial production” of 150 units was then built at the Leitz factory in Midland, Ontario (Canada).
Today, the Leica 72 is a sought-after collector’s item.