The Heidoscop is a stereo camera with a reflex viewfinder, for plates or film packs (or a roll film back can be used). It was the first camera made by Franke and Heidecke (later Rollei-Werke Franke & Heidecke) in Braunschweig, Germany. It is a fairly close copy of Voigtländer's Stereflektoskop of 1914. Like that camera, the Heidoscop was made in two sizes: the first takes 45×107 mm plates, and was made from 1921-34. This was followed in 1925 by a model for 6×13 cm plates or film; this model was made until 1940. The exact specification was changed during production, so a number of types can be distinguished.
The camera has a pair of taking lenses mounted in a stereo Compound shutter. In most of the cameras (all the later types) the taking lenses are f/4.5 Tessars (5.5 cm focal length for the first model, and 7.5 cm for the second). When the camera was first introduced, Heidoscop or Steinheil Unifocal lenses were offered as alternative taking lenses. There is a viewing lens centrally between these. This is also a Tessar in some cameras, and a 'Sucher-Triplet' (also by Zeiss) or 'Heidoscop Sucher-Anastigmat' in others.
The camera allows front rise; the front section of the body, containing the lenses and shutter, simply slides upward with manual pressure.
On the top of the camera body there is a collapsible hood over the viewing screen. This would even then be a familiar feature of reflex cameras. It has a built-in focusing loupe, and a mirror, allowing the hood to be used as an eye-level reflex finder. There is even a spirit level visible in the finder.
Only a few years after the Heidoscop, in 1926, very similar cameras but with a built-in roll-film chamber were introduced alongside it, in both sizes. This was named the Rolleidoscop, although McKeown states that the earliest of these were sold with the name Heidoscop.
- The article about the Heidoscop at Early Photography lists the main changes in the design of the Heidoscop, and shows examples of two versions of the camera.
- McKeown, James M. and Joan C. McKeown's Price Guide to Antique and Classic Cameras, 12th Edition, 2005-2006. USA, Centennial Photo Service, 2004. ISBN 0-931838-40-1 (hardcover). ISBN 0-931838-41-X (softcover). p850.
- Article on the 6×13 cm Heidoscop (in French) by Henri Peyre at Photo-Stereo.
- Examples at past auctions by Westlicht Photographica Auction (now Leitz Photographica Auction):
- Heidoscop, 45x107 mm, 1930 (serial no. 7533), offered at Camera Auction 26, on 22 November 2014.
- Heidoscop, 6x13 cm, 1935 (serial no. 72453), with two plate magazines, a single plate-holder, filters and leather cases; also at Camera Auction 26.
- Heidoscop, 6×13 cm, about 1924 (from the lens serial), with a plate magazine back, and a Heidoplast stereo viewer; sold at Camera Auction 20, in November 2011.
- Heidoscop, 45×107 mm, 1923, with a roll film back; a lot in an auction in September 2006 by Auction Team Breker in Cologne.
- Heidoscop, 45×107 mm, about 1927 (from the lens serial); a lot in the auction of the Kaprelian Camera Collection in November 2011 by Fullers LLC in Philadelphia. Several excellent photographs of the camera, with a plate magazine back.
- Heidoscop, 45×107 mm, 1931, with a plate magazine back; another lot in the 2006 auction in Cologne.
- Heidoscop 6×13 cm with Zeiss Triplet viewing lens and a roll film back; a lot in an auction in January 1999 by Christie's in London.
- Heidoscop at Welt der Stereoskopie; many excellent pictures of the camera.
- 1929 Brochure for the Heidoscop and Rolleidoscop (in German) at Welt der Stereoskopie.
- Instructions for Heidoscop and Rolleidoscop (in English) at Robert R. Thurston's Stereo Images from Juneau site.