The front of a Kinaflex twin-lens reflex camera. The focus rings of the two lenses are coupled with gears around their circumference in this simple design.
A twin-lens reflex camera (TLR) 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" (the lens that takes the picture), while the other is used for the viewfinder system,[1] which is usually viewed from above at waist level.
In addition to the objective, the viewfinder consists of a 45-degree mirror (the reason for the word reflex in the name), 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 to save on the mechanical complexity. 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 35mm film. Few general-purpose digital TLR cameras exist, since the heyday of TLR cameras ended long before the era of digital cameras, though they can be adapted with digital backs. In 2015, MiNT Camera released Instantflex TL70, a twin-lens reflex camera that uses Fuji instax mini film.
History
Sketch of an early-20th-century twin-lens reflex camera
In traditional cameras, the photographer first viewed the image on a screen of ground glass in the same place that a photographic plate would be placed. 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.[2]) With the addition of a second lens and a permanent piece of ground glass, this made it possible for a photographer to snap a picture immediately after focusing the image instead of having to remove and replace the ground glass screen every shot.[3] This advantage of course applies to SLR cameras as well, but early SLR cameras caused delays and inconvenience due to moving 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.[4] 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 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.[5]
TLRs are still manufactured in Germany by DHW Fototechnik, the successor of Franke & Heidecke, in three versions.[6]
Higher-end TLRs may have a pop-up magnifying glass to assist the user in focusing the camera. In addition, many have a "sports finder" consisting of a square hole punched in the back of the pop-up hood, and a knock-out in the front. Photographers can sight through these instead of using the matte screen. This is especially useful in tracking moving subjects such as animals or race cars, since the image on the matte screen is reversed left-to-right. It is nearly impossible to accurately judge composition with such an arrangement, however.
Mamiya's C-Series, introduced in the 1960s, the C-3, C-2, C-33, C-22 and the Mamiya C330 and Mamiya C220 along with their predecessor the Mamiyaflex,[7] are the main conventional TLR cameras to feature truly interchangeable lenses.[8] "Bayonet-mount" TLRs, notably Rolleis & Yashicas, had both wide-angle and tele supplementary front add-ons, with Rollei's Zeiss Mutars being expensive but fairly sharp. Rollei also made separate TLRs having fixed wide-angle or tele lenses: the Tele Rollei and the Rollei Wide, in relatively limited quantities; higher sharpness, more convenient (faster than changing lenses) if one could carry multiple cameras around one's neck, but much more costly than using 1 camera with supplements. The Mamiya TLRs also employ bellows focusing, making extreme closeups possible.
Many TLRs used front and back cut-outs in the hinged top hood to provide a quick-action finder for sports and action photography. Late model RolleiRolleiflex TLRs introduced the widely copied additional feature of a second-mirror "sports finder". When the hinged front hood knock-out is moved to the sports finder position a secondary mirror swings down over the view screen to reflect the image to a secondary magnifier on the back of the hood, just below the direct view cutout. This permits precise focusing while using the sports finder feature. The magnified central image is reversed both top-to-bottom and left-to-right. This feature made Rolleis the leading choice for press photographers during the 1940s to 1960s.[9]
Advantages
1957 Kodak Duaflex IV, an inexpensive fixed-focus TLR
A primary advantage of the TLR is in its mechanical simplicity as compared to the more common single-lens reflex cameras (SLR) cameras. The SLR must employ some method of blocking light from reaching the film during focusing, either with a focal plane shutter (most common) or with the reflex mirror itself. Both methods are mechanically complicated and add significant bulk and weight, especially in medium-format cameras. Because of their mechanical simplicity, TLR cameras are considerably cheaper than SLR cameras of similar optical quality, as well as inherently less prone to mechanical failure.
TLRs are practically different from SLR in several respects. First, unlike virtually all film SLRs, TLRs provide a continuous image on the finder screen. The view does not black out during exposure. Since a mirror does not need to be moved out of the way, the picture can be taken much closer to the time the shutter is actuated by the photographer, reducing so-called shutter lag. This trait, and the continuous viewing, made TLRs the preferred camera style for dance photography.[10] The separate viewing lens is also very advantageous for long-exposure photographs. During exposure, an SLR's mirror must be retracted, blacking out the image in the viewfinder. A TLR's mirror is fixed and the taking lens remains open throughout the exposure, letting the photographer examine the image while the exposure is in progress. This can ease the creation of special lighting or transparency effects. Models with leaf shutters within the lens, rather than focal-plane shutters installed inside the camera body, can synchronize with flash at higher speeds than can SLRs. Flashes on SLRs usually cannot synchronize accurately when the shutter speed is faster than 1/60th of a second and occasionally 1/125th. Some higher quality DSLRs can synchronize at up to 1/500th of a second. Leaf shutters allow for flash synchronization at all shutter speeds. SLR shutter mechanisms are comparatively noisy. Most TLRs use a leaf shutter in the lens. The only mechanical noise during exposure is from the shutter leaves opening and closing.
TLRs are also ideal for candid camera shots where an eye-level camera would be conspicuous. A TLR can be hung on a neck strap and the shutter fired by cable release. Owing to the availability of medium-format cameras and the ease of image composition, the TLR was for many years also preferred by many portrait studios for static poses.
Extreme dark photographic filters like the opaque Wratten 87 can be used without problems, as they cover and thus darken only the taking lens. The image in the viewfinder stays bright.
Disadvantages
Few TLR cameras offered interchangeable lenses and none were made with a zoom lens. In systems with interchangeable lenses, such as the Mamiya, the fixed distance between the lenses sets a hard limit on their size, which precludes the possibility of large aperture long-focus lenses. The lenses are also more expensive because the shutter mechanism is integrated with the lens, not the camera body, so each lens pair must include a shutter. Because the photographer views through one lens but takes the photograph through another, parallax error makes the photograph different from the view on the screen. This difference is negligible when the subject is far away, but is critical for nearby subjects. Parallax compensation may be performed by the photographer in adjustment of the sight line while compensating for the framing change, or for highly repeatable accuracy in tabletop photography (in which the subject might be within a foot (30cm) of the camera), devices are available that move the camera upwards so that the taking lens goes to the exact position that the viewing lens occupied. [Mamiya's very accurate version was called the Para-mender, and mounted on a tripod.] Some TLRs like the Rolleiflex (a notable early example is the Voigtländer Superb of 1933[11]) also came with - more or less complex - devices to adjust parallax with focussing. It is generally not possible to preview depth of field, as one can with most SLRs, since the TLR's viewing lens usually has no diaphragm. Exceptions to this are the Rolleiflex, the Mamiya 105 D and 105 DS lenses, which have a depth of field preview.
As the viewfinder of a TLR camera requires the photographer to look down toward the camera, it is inconvenient to frame a photo with a subject that requires the camera to be positioned above the photographer's chest unless a tripod is used. In these cases, the camera may be positioned with the lenses oriented horizontally. Due to the TLR's square format, the composition need not be altered. The image in the waist-level finder is reversed 'left to right' which can make framing a photograph difficult, especially for an inexperienced user or with a moving subject. With high-quality TLRs like the Rolleiflex and the Mamiya C220/C330 the waist-level finder can be replaced by an eye-level finder, using a roof pentaprism or pentamirror to correct the image while making it viewable through an eyepiece at the rear of the camera.
The design of the leaf shutter limits almost all TLRs to a maximum shutter speed between 1/100th and 1/500th of a second.
Certain photographic filters are inconvenient without line of sight through the taking lens - notably, graduated neutral density filters are hard to use with a TLR, as there is no easy way to position the filter accurately.
Film formats
Instantflex TL70Gemflex twin lens reflex cameraGoerz Minicord III twin lens reflex 16mm cameraTessina TLRSharan Rolleiflex 2.8F TLR Minox film camera
6×6 format
The typical TLR is medium format, using 120roll film with square 6 cm × 6 cm images. Presently, the Chinese Seagull Camera is still in production along with Lomography's Lubitel, but in the past, many manufacturers made them. DHW-Fototechnik GmbH continues to make the Rolleiflex TLR as well.[12] The Ciro-flex, produced by Ciro Cameras Inc., rose dramatically in popularity due in large part to the inability to obtain the German Rollei TLRs during World War II. The Ciro-flex was widely accessible, inexpensive, and produced high quality images.[13] Models with the Mamiya, Minolta and Yashica brands are common on the used-camera market, and many other companies made TLRs that are now classics. The Mamiya C series TLRs had interchangeable lenses, allowing focal lengths from 55mm (wide angle) to 250mm (telephoto) to be used. The bellows focusing of these models also allowed extreme closeups to be taken, something difficult or impossible with most TLRs. The simple, sturdy construction of many TLRs means they have tended to endure the years well. Many low-end cameras used cheap shutters however, and the slow speeds on these often stick or are inaccurate.
127 format
There were smaller TLR models, using 127roll film with square 4 cm × 4 cm images, most famous the "Baby" Rolleiflex and the Yashica 44. The TLR design was also popular in the 1950s for inexpensive fixed focus cameras such as the Kodak Duaflex and Argus 75.
35mm format
Though most used medium format film, a few 35mm TLRs were made, the very expensive Contaflex TLR[14] being the most elaborate, with interchangeable lenses and removable backs. The LOMO Lubitel 166+, a natively medium format camera, comes with an adapter for 35mm film. As do most Rolleiflex models with their respective Rolleikin 35mm adapter. Furthermore the Yashica 635 was made specifically for use with 120 and 135 film and was shipped with the appropriate adapters.
Instant film format
The only twin lens reflex camera that uses instant film is Instantflex TL70 manufactured by MiNT Camera which is compatible with Fuji instax mini film (film size 54 mm × 86 mm, picture size 46 mm × 62 mm) . It is the world's first instant twin lens reflex camera.
Subminiature format
Gemflex is a subminiature twin lens reflex camera made by Showa Optica Works (昭和光学精機) in occupied Japan in the 50s.[15] Gemflex resembles the well known Rolleiflex 6×6 twin lens reflex, but much smaller in size. The body of Gemflex is die cast from shatter proof metal.[16]
The smallest photography TLR camera using 35mm film is the Swiss-made Tessina, using perforated 35mm film reloaded into special Tessina cassette, forming images of 14 mm × 21 mm.
Goerz Minicord twin lens reflex made 10 mm × 10 mm format on double perforated 16mm film in metal cassette. 6 Element Goerz Helgor F2 lens, metal focal plane shutter B, 10, 25, 50, 100, and 400. Viewing lens uses pentaprism reflex optics for the viewing lens. Picture format 10 mm × 10 mm on double perforated 16mm film.
Minox rebadged Sharan Rolleflex 2.8F classic retro TLR film camera, 1/3 scale 6x6 Rolleiflex TLR, using Minox cassette image size 8 mm × 11 mm, 15mm F5.6 glass triplet lens, mechanical shutter 1/250 sec.
Japan made Gemflex, a twin lens reflex using 17.5mm paper back roll film.
It has been argued that the medical gastroscopy camera, the Olympus Gastro Camera[17] is technically the smallest TLR device.
↑ However, the (6×6cm) Koniflex (from Konica) is one of several others sold in small volumes to have a supplementary tele lens, and the (6×7cm) Koni-Omegaflex (cited above) can be used as a TLR with an optional finder and has interchangeable lenses.
↑ Ian Parker: Complete Rollei Collector's Guide, 1993
A single-lens reflex camera (SLR) is a camera that typically uses a mirror and prism system that permits the photographer to view through the lens and see exactly what will be captured. With twin lens reflex and rangefinder cameras, the viewed image could be significantly different from the final image. When the shutter button is pressed on most SLRs, the mirror flips out of the light path, allowing light to pass through to the light receptor and the image to be captured.
A camera is an instrument used to capture and store images and videos, either digitally via an electronic image sensor, or chemically via a light-sensitive material such as photographic film. As a pivotal technology in the fields of photography and videography, cameras have played a significant role in the progression of visual arts, media, entertainment, surveillance, and scientific research. The invention of the camera dates back to the 19th century and has since evolved with advancements in technology, leading to a vast array of types and models in the 21st century.
A rangefinder camera is a camera fitted with a rangefinder, typically a split-image rangefinder: a range-finding focusing mechanism allowing the photographer to measure the subject distance and take photographs that are in sharp focus. Most varieties of rangefinder show two images of the same subject, one of which moves when a calibrated wheel is turned; when the two images coincide and fuse into one, the distance can be read off the wheel. Older, non-coupled rangefinder cameras display the focusing distance and require the photographer to transfer the value to the lens focus ring; cameras without built-in rangefinders could have an external rangefinder fitted into the accessory shoe. Earlier cameras of this type had separate viewfinder and rangefinder windows; later the rangefinder was incorporated into the viewfinder. More modern designs have rangefinders coupled to the focusing mechanism so that the lens is focused correctly when the rangefinder images fuse; compare with the focusing screen in non-autofocus SLRs.
Medium format has traditionally referred to a film format in photography and the related cameras and equipment that use film. Nowadays, the term applies to film and digital cameras that record images on media larger than the 24 mm × 36 mm used in 35 mm photography, but smaller than 4 in × 5 in.
Mamiya Digital Imaging Co., Ltd. is a Japanese company that manufactures high-end cameras and other related photographic and optical equipment. With headquarters in Tokyo, it has two manufacturing plants and a workforce of over 200 people. The company was founded in May 1940 by camera designer Seiichi Mamiya and financial backer Tsunejiro Sugawara.
In photography, a viewfinder is a small window the photographer looks through to see what a photo will look like before they capture it.
Rollei was a German manufacturer of optical instruments founded in 1920 by Paul Franke and Reinhold Heidecke in Braunschweig, Lower Saxony, and maker of the Rolleiflex and Rolleicord series of cameras. Later products included specialty and nostalgic type films for the photo hobbyist market.
Rolleiflex is the name of a long-running and diverse line of high-end cameras originally made by the German company Franke & Heidecke, and later Rollei-Werke.
Contax began as a German camera model in the Zeiss Ikon line in 1932, and later became a brand name. The early cameras were among the finest in the world, typically featuring high quality Zeiss interchangeable lenses. The final products under the Contax name were a line of 35 mm, medium format, and digital cameras engineered and manufactured by Japanese multinational Kyocera, and featuring modern Zeiss optics. In 2005, Kyocera announced that it would no longer produce Contax cameras. The rights to the brand are currently part of Carl Zeiss AG, but no Contax cameras are currently in production, and the brand is considered dormant.
The Rolleiflex SL35 is a range of SLR cameras manufactured and sold by the German camera maker Rollei from 1970 to 1982. This range of cameras uses 35mm film. The camera bodies were initially made in Germany. After Zeiss Ikon discontinued camera production, Rollei acquired the Voigtländer brand and camera designs in 1972, and began producing a second generation of SLR cameras in Singapore starting from 1976. Some of those second-generation cameras were rebranded and marketed as Voigtländer VSL.
The history of the single-lens reflex camera (SLR) begins with the use of a reflex mirror in a camera obscura described in 1676, but it took a long time for the design to succeed for photographic cameras. The first patent was granted in 1861, and the first cameras were produced in 1884, but while elegantly simple in concept, they were very complex in practice. One by one these complexities were overcome as optical and mechanical technology advanced, and in the 1960s the SLR camera became the preferred design for many high-end camera formats.
Yashica Co., Ltd. was a Japanese manufacturer of cameras, lenses, and film editing equipment active from 1949 until 2005 when its then-owner, Kyocera, ceased production. It acquired the lens manufacturer Tomioka.
The Rollei 35 is a 35mm miniature viewfinder camera built by Rollei. The original Rollei 35, when introduced at photokina in 1966, was the smallest existing 135 film camera. The Rollei 35 series remains one of the smallest 35 mm cameras after the Minox 35 and Minolta TC-1. In 30 years, about 2 million Rollei 35 series cameras were manufactured. The Rollei 35 was manufactured by DHW Fototechnik up to 2015, the successor of Franke & Heidecke as small-batch production. The last version is the Rollei 35 Classic, an updated Rollei 35 SE.
The Mamiya C220 is a lightweight twin-lens reflex camera made in the early 1970s by the Japanese camera manufacturer Mamiya. The camera has interchangeable lenses ranging from 55 mm wide-angle to 250 mm telephoto and accepts 120 and 220 rollfilms. The rack and pinion focusing system with a bellows makes it possible for close-up photography without attachments. The straight film path has no sharp turns for absolute flatness of the film.
The Rolleiflex SL66 is a medium format single lens reflex camera made by Rollei, in regular production from 1966–82. Although Rollei never officially discontinued the Rollei SL66, it was removed from their promotional support and dealer catalogs in the UK from 1976 and for all intents and purposes was replaced by the Rolleiflex SLX. The UK importer was Rollei themselves. The Rolleiflex SL66 did not feature in Rollei's worldwide product catalog in 1980, and the US importer's July 1979 dealer price list has no SL66 cameras nor 40mm, 250mm, or 500mm lenses. This strongly suggests that the camera was effectively discontinued from 1976 until the launch of the SL66E in October 1982 after the restart of camera production following the first bankruptcy.
The Contaflex series is a family of 35mm Single-lens reflex cameras (SLR) equipped with a leaf shutter, produced by Zeiss Ikon in the 1950s and 1960s. The name was first used by Zeiss Ikon in 1935 for a 35mm Twin-lens reflex camera, the Contaflex TLR; for the earlier TLR, the -flex suffix referred to the integral reflex mirror for the viewfinder. The first SLR models, the Contaflex I and II have fixed lenses, while the later models have interchangeable lenses; eventually the Contaflexes became a camera system with a wide variety of accessories.
Through the Viewfinder (TtV) photography is a photographic or videographic technique in which a photograph or video or motion picture film is shot with one camera through the viewfinder of a second camera. The viewfinder thus acts as a kind of lens filter. The most popular method involves using a digital camera as the image taking camera and an intact twin-lens reflex camera (TLR) or pseudo-TLR as the "viewfinder" camera. TLRs typically have square waist-level viewfinders, with the viewfinder plane at 90 degrees to the image plane. The image in a TLR viewfinder is laterally reversed, i.e. it is a mirror image. Most photographers use a cardboard tube or other apparatus connecting the two cameras in order to eliminate stray light and prevent reflections from appearing on the viewfinder glass or on the lens of the imaging camera.
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The Mamiya C series is a line of twin-lens reflex medium-format system cameras manufactured by Mamiya between 1956 and 1994. It was developed from the Mamiyaflex series of cameras built from 1949 to 1956. The Mamiya C series was initially aimed at the professional market, but some later models were intended for amateurs.
The Mamiya RB67 is a professional medium format single-lens reflex system camera manufactured by Mamiya. There are three successive models: the RB67 Professional, RB67 Pro-S and RB67 Pro-SD. It is primarily designed for studio use, but can also be used in the field.
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