page_title: Twin-lens reflex camera
section_title: History
hierarchical_section_title: Twin-lens reflex camera / History
caption_attribution_description: Twin Lens Camera sketch from Hints to Travellers: Scientific and General (pre 1923)
context_page_description: A twin-lens reflex camera is a type of camera with two objective lenses of the same focal length. One of the lenses is the photographic objective or "taking lens", while the other is used for the viewfinder system, which is usually viewed from above at waist level.
  In addition to the objective, the viewfinder consists of a 45-degree mirror, a matte focusing screen at the top of the camera, and a pop-up hood surrounding it. The two objectives are connected, so that the focus shown on the focusing screen will be exactly the same as on the film. However, many inexpensive 'pseudo' TLRs are fixed-focus models. Most TLRs use leaf shutters with shutter speeds up to 1/500 of a second with a bulb setting.
  For practical purposes, all TLRs are film cameras, most often using 120 film, although there are many examples which used 620 film, 127 film, and 35 mm film. No general-purpose digital TLR cameras exist, since the heyday of TLR cameras ended long before the era of digital cameras. In 2015, MiNT Camera released Instantflex TL70, a twin-lens reflex camera that uses Fuji instax mini film.
context_section_description: Double-lens cameras were first developed around 1870.
  In the earlier plate cameras the photographer first viewed the image on a screen of ground glass. After adjusting the camera and closing the objective aperture the ground glass screen was swapped for the photographic plate, and finally the picture could be taken. (Some cameras used this layout as late as the 1960s, for example the Koni-Omegaflex.)
  The additional viewfinding optics made it possible for a photographer to snap a picture immediately after focussing the image.
  This advantage of course applies to SLR cameras as well, but early SLR cameras caused delays and inconvenience to move the mirror needed for viewfinding out of the optical path to the photographic plate. When this process was automated, the movement of the mirror could cause shake in the camera and blur the image.
  Using a mirror to allow viewing from above also enabled the camera to be held much more steadily against the body than a camera held with the hands only.
  The London Stereoscopic Co's "Carlton" model, dating from 1885, is claimed to be the first off-the-shelf TLR camera.
  A major step forward to mass marketing of the TLR came with the Rolleiflex in 1929, developed by Franke & Heidecke in Germany. The Rolleiflex was widely imitated and copied and most mass-market TLR cameras owe much to its design. It is said that Reinhold Heidecke had the inspiration for the Rollei TLRs while undertaking photography of enemy lines from the German trenches in 1916, when a periscopic approach to focusing and taking photos radically reduced the risk to the photographer from sniper fire.
  TLRs are still manufactured in Germany by DHW Fototechnik, the successor of Franke & Heidecke, in three versions.
caption: Sketch of an early-20th-century twin-lens reflex camera
exif: {}