Rolleiflex twin-lens reflex

The Rolleiflex twin-lens reflex is a series of medium-format roll-film cameras originally created in Germany by Franke & Heidecke, later known as Rollei-Werke. First introduced in 1929, the design employs two lenses of identical focal length: an upper viewing lens reflecting an image onto a top matte screen via a forty-five-degree mirror, and a lower taking lens that exposes the film. Marketed primarily to professional photographers, the premier Rolleiflex line established the twin-lens reflex configuration as an industry standard.

The camera was conceived after Reinhold Heidecke explored periscopic viewing principles during the First World War. While the 1929 original used 117 roll film, subsequent editions adopted 120 film, alongside 127 film for the compact Baby Rolleiflex. The Old Standard introduced a hinged back and resettable frame counter, while the 1937 Automat introduced a mechanism that sensed paper backing thickness to automate frame counting, eliminating the traditional ruby inspection window. Dedicated versions with alternative fixed focal lengths were also produced, including the Tele-Rolleiflex and Wide-Rolleiflex. German manufacture continued under successor firm DHW Fototechnik until 2014.

Constructed for waist-level operation beneath a pop-up viewing hood, the Rolleiflex pairs linked optics with leaf shutters reaching speeds of 1/500 of a second. High-grade optics were supplied by Carl Zeiss and Schneider-Kreuznach, including Tessar, Xenar, Planar, and Xenotar formulas. Distinguishing features across various models include a rapid-advance crank that automatically spaces exposures and tensions the shutter, bayonet mounts around the lenses for dedicated accessories, and viewing hoods equipped with pop-up magnifiers or dual-mirror sports finders for eye-level focusing.

Unlike simpler TLRs and the amateur Rolleicord line, advanced Rolleiflex models incorporate automatic mechanical frame counting rather than a rear red inspection window.