The Rollei success story began with the introduction of the Baby Heidoscop camera in 1921. This stereo camera was the forerunner of the twin lens reflex.
Franke & Heidecke manufactured 6 stereo cameras which were the only Rollei cameras manufactured between 1921 and 1929. Production continued until about 1941, but they were made to order in the 1930s.
Four versions of the camera were made to use plate film, the Heidoscop-named after their designer, Reinhold Heidecke, and two were designed to use roll film-named again after the designer with the addition of roll for roll film. When you look at the hood on the top of the camera, it's easy to see that the viewing system was basically the same as was used in the immensely popular twin lens reflex cameras.
The picture immediately above shows a Rolleidoscop (see the roll film chambers) and the familiar hood that was used on all twin lens Rolleis.
The picture below shows one of the first twin lens reflex cameras, the Art Deco Rolleicord 1 from 1933. See the resemblance?
