STEREO PHOTOGRAPHY WITH THE LEICA CAMERA

The primary goal of stereo photography is to create two nearly identical photographs that, when combined, give the illusion of a third dimension³⁶⁰. This effect had already been achieved through stereoscopy; as early as 1838, Charles Wheatstone demonstrated the practical use of his mirror stereoscope, utilizing drawings of solid geometric figures³⁶⁰. From the outset, pioneers in photography embraced the challenge of producing stereo images, leading to the availability of various stereo apparatus³⁶⁰. By the 1850s, the popularity of stereo photographs made them a foundational element of visual education³⁶⁰.

At the time the Leica was introduced, the stereo market was dominated by cameras that used 45 x 107mm and 60 x 130mm formats³⁶⁰. Notable examples include the Voigtlander Stereolektroskop, Heidoscope, and the Franke and Heidecke Rolleidoscope³⁶⁰. One should also mention the Richard Homeos 35mm stereo camera, which produced a pair of 18 x 24mm negatives on perforated 35mm film³⁶⁰. Despite being ahead of its time, this camera was not commercially successful, with fewer than one thousand units produced³⁶⁰.

Oskar Barnack recognized the potential of using the Leica for stereo photography from the beginning³⁶⁰. There was a clear commercial incentive to capture a share of the market, which was largely controlled by large-format stereo cameras³⁶⁰.

The fundamental challenge of taking two photographs of the same subject from viewpoints just a few inches apart can be addressed in two ways³⁶⁰. The first method is to take two separate exposures consecutively with the same camera³⁶⁰. The second method employs a 'double' camera equipped with two identical lenses that capture the same image simultaneously³⁶⁰. Over time, Barnack, Albert, and their colleagues experimented with both approaches³⁶⁰. However, the first method, demonstrated by the stereo slide bar, was quickly replaced by the second method, represented by the double stereo Leica and its variants³⁶⁰.

The FIATE Stereo Slide Bar

The FIATE Stereo Slide Bar, which was the first stereo device introduced by Leitz, debuted in 1929 and remained available until 1939, as indicated by the last general catalogue published before the war³⁶⁰. This stereo slide bar measures 18.5 cm in length and is designed to fit into a niche between the tripod and the camera³⁶⁰. It allows lateral movement of the camera along a length of 75 to 150 mm³⁶⁰. To use it, the photographer takes one photograph, then moves the camera along the bar to capture a second exposure³⁶⁰. Given that the average distance between a person's eyes, known as interocular distance, is about 64 mm, it is typical to allow for a movement of 75 mm for close-up work and 150 mm for distant landscapes³⁶⁰. The exposures taken with the FIATE slide bar are of a format measuring 24 × 36 mm³⁶⁰.

The design of the FIATE is ultimately based on a stereo camera invented by Powell in the 1850s, which was a small wooden box camera that could slide along a wooden rail to take two separate exposures³⁶⁰. Powell's camera featured a 'toeing-in' device that allowed for the second exposure to be taken at the same angle to the center of the photograph as the first one³⁶⁰. However, the theory behind this method of stereo photography was later proven to be incorrect, leading Barnack to omit the 'toeing-in' device from the FIATE³⁶⁰.

There are minor variations of the standard model, primarily differences in the engraving³⁶⁰. Reports suggest that a smaller variant may have been produced³⁶⁰.

In the 19th century, pioneers of stereo photography primarily focused on capturing immobile subjects³⁶⁰. However, by the 1920s, this had changed significantly³⁶⁰. A major limitation of the FIATE stereo slide bar was its inability to photograph anything but stationary subjects.³⁶⁰ Despite being on the market for nearly ten years, it remained a novelty rather than a serious accessory for Leica users³⁶⁰. The challenge of photographing moving subjects would eventually be addressed by the stereo Leica and its successors³⁶⁰.

A report from October 11, 1941, states that Wilhelm Albert developed a similar stereo rail for military use in 1941³⁶⁴. This rail featured a 1-meter-long base and was designed to hold two Leica cameras equipped with a double wire release³⁶⁴.

The Stereo Leica

Barnack's next concept for a stereo Leica, developed around 1936, was significantly more complex³⁶⁰. The double stereo Leica, also known as the Stereo Leica, is essentially two half-frame Leicas designed to operate simultaneously³⁶⁰. This Stereo Leica was equipped with two identical lenses, typically 35mm Elmars, as the 35mm focal length is considered fairly standard for the 18 x 24mm format³⁶⁰. To ensure that the stereo photographs matched in size, it was crucial to use lenses with identical real focal lengths³⁶⁰. However, during the 1920s, 5cm Elmars had focal lengths ranging from 47.5mm to 52.5mm, making it extremely challenging to find two matching lenses for the Stereo Leica³⁶⁰. This issue ultimately diminished the commercial viability of the model, which never went beyond the prototype stage³⁶⁰. Unfortunately, none of the several prototypes produced seems to have survived³⁶⁰.

The STEREOLY Leitz Beam-splitter

At the Leipzig Spring Fair of 1931, Leitz introduced a stereo beam-splitter device called the STEREOLY, designed by the renowned optical engineer Professor Lihotsky³⁶⁰. The STEREOLY primarily consists of a unit incorporating two separate prisms that are 7mm apart³⁶⁰. Each prism is fitted with a bracket that allows it to be adaptable to any 5cm lens, which means the 24 × 36mm image is divided into two 18 × 24mm frames³⁶⁰.

Compared to the stereo slide bar, the main advantage of the STEREOLY is its capability for instantaneous photography³⁶⁰. However, its primary drawback is that the 5cm lens, when used with an 18 × 24mm portion of film, creates a telephoto effect³⁶⁰. This effect is excellent for portraits but unsatisfactory for landscapes³⁶⁰.

The STEREOLY was produced until 1939 and was initially available only for the Leica I Model A and Leica I Model C³⁶⁰. The bracket holding the prism in front of the lens has two notches: one for the 5cm Elmar lens and the other for the 5cm Hektor lens³⁶⁰. These two positions are necessary to accommodate the size differences between the lenses³⁶⁰.

The earliest type of bracket was immobile and included a mask that reduced the frame from 24 × 36mm to 18 × 24mm for the viewfinders of the Leica I Model A and Leica I Model C³⁶⁰. Later, a new, rotating bracket was introduced, allowing users to quickly switch between viewing both the full frame and the half-frame³⁶⁰. With the advent of the Leica III with a coupled rangefinder, a differently shaped bracket was produced to account for the height of the rangefinder³⁶⁰. This bracket also featured an optical 18 × 24mm viewfinder instead of just a mask³⁶⁰. Over time, this model was fitted with a third notch for the newly introduced Summar lens³⁶⁰. Finally, according to the catalogs, a special bracket was announced to enable the STEREOLY to be used with the Leica IIIb, although it is questionable whether this bracket was ever actually produced³⁶⁰.

In conjunction with the STEREOLY, a stereo viewer, code-named VOTRA, was offered³⁶⁰. This beautifully crafted device features individually adjustable eyepieces and an adjustable interpupillary distance³⁶⁰. The viewer can be held in hand or fixed to a sturdy table stand, code-named VOTIV³⁶⁰. Finished in nickel and sold in a velvet-lined coffret case, it is considered one of the most attractive accessories from Leitz³⁶⁰.

A report from May 7, 1952, indicates that Wilhelm Albert and Willi Schmidt developed a 4x stereo viewing magnifier with a field lens and a 5x stereo viewing magnifier with adjustable eyepieces in sheet metal design³⁶⁴. A similar prototype was sold at the 35th Leitz Photographica Auction on November 23, 2019, for 10800 Euros, including the buyer's premium.

Combination of Two Leica Cameras

The next step taken by Leitz was to achieve a stereo effect by using two Leica cameras in combination³⁶⁰. Unlike the Stereo Leica, which utilized two model 72s, this development used two standard production Leicas³⁶⁰. This innovation was spearheaded by Albert, who continued the company's research in stereo photography after Barnack's death in 1937³⁶⁰. He designed a long base that accommodated two Leicas, positioned one above the other³⁶⁰ in 1937, according to a report from February 17 of the same year³⁶⁴. Both cameras could be fired simultaneously using a double cable release, and the lateral shift could be adjusted by changing the distance between the two cameras³⁶⁰. Although this design remained in the experimental stage, a similar line of development was pursued later by Professor Schmidt, who was working for Leitz in 1951³⁶⁰.

Additionally, it is worth mentioning the 'tandem' Leica³⁶⁰. In this configuration, two Leicas are mounted one above the other in an upright position, linked by a special baseplate attached to the upper camera³⁶⁰. This equipment (coded TOWIN) was produced by Leitz New York and could also be used for purposes unrelated to stereo photography, such as combining two different lenses or films³⁶⁰.

According to Leitz Auction #34 Booklet, TOWIN was invented in the 1940s by W. Berssenbrugge, an expert in colour and stereo photography. It was originally made for stereo exposures, however, in 1949 Leitz advertised it as a device for simultaneous exposures in black and white and colour.

Other Stereo Lens Units

The 9 cm f/7 twin-lens stereo unit should be mentioned briefly³⁶⁰. It was never manufactured, likely due to the incompatibility between slow shutter speeds and telephoto lenses, although a prototype was created³⁶⁰.

A report from March 12, 1942 indicated that Wilhelm Albert developed a stereo attachment with a rotating aperture for "large" format shots³⁶⁴.

A report from July 3, 1946, indicates that in 1946 Wilhelm Albert and Willi Schmidt developed a stereo close-up attachment for 30 cm and 50 cm object distances, featuring a rangefinder, deflection wedge, and viewfinder³⁶⁴.

A report from October 13, 1949, indicates that Wilhelm Albert and Willi Schmidt developed a prism attachment for stereo lenses that utilized the person-tone separation (Person-Tontrenn-Verfahren) method in 1949³⁶⁴.

A report from September 25, 1950, indicates that Karl Clös developed a small stereo prism attachment for that utilized tone separation (Tontrennung) method³⁶⁴.

A report from November 29, 1952, indicates that Karl Clös developed a 9cm stereo lens for close-up photography³⁶⁴.

Around 1968, Leitz produced the 24 mm Summar stereo lens on special order for the Israeli government³⁶⁰. This lens, designed to take a pair of 12 × 36 mm photographs, can only be used for static stereo photography, as it must be rotated 180 degrees from position 1 to position 2³⁶⁰. It appears that only one example of this lens has survived³⁶⁰.

The Stemar, considered Leitz's finest contribution to stereo photography, was a remarkable technical achievement³⁶⁰. However, it did not attract a large number of photographers, partly due to its high price and also likely because it was released during a decline in interest in stereo photography³⁶⁰. This explains the limited production of the unit in Midland, Ontario, and its early discontinuation³⁶⁰.

Speculatively, a prism with progressively adjustable shifts might have boosted its popularity³⁶⁰. Nonetheless, Zeiss and Nikon produced nearly identical lenses and setups—Zeiss for their Contax cameras and Nikon for their rangefinder models³⁶⁰. Perhaps the greatest testament to the Stemar is that it was emulated by two of the finest camera manufacturers in the world³⁶⁰.

Other Stereo Lens Units

The 9 cm f/7 twin-lens stereo unit should be mentioned briefly³⁶⁰. It was never manufactured, likely due to the incompatibility between slow shutter speeds and telephoto lenses, although a prototype was created³⁶⁰.

A report from March 12, 1942 indicated that Wilhelm Albert developed a stereo attachment with a rotating aperture for "large" format shots³⁶⁴.

A report from July 3, 1946, indicates that in 1946 Wilhelm Albert and Willi Schmidt developed a stereo close-up attachment for 30 cm and 50 cm object distances, featuring a rangefinder, deflection wedge, and viewfinder³⁶⁴.

A report from October 13, 1949, indicates that Wilhelm Albert and Willi Schmidt developed a prism attachment for stereo lenses that utilized the person-tone separation (Person-Tontrenn-Verfahren) method in 1949³⁶⁴.

A report from September 25, 1950, indicates that Karl Clös developed a small stereo prism attachment for that utilized tone separation (Tontrennung) method³⁶⁴.

A report from June 26, 1953, indicates that Wilhelm Albert developed a stereo prism head with a protective cover³⁶⁴.

A report from December 7, 1953, indicates that Wilhelm Albert and Mr. Bock developed a 5x stereo viewing magnifier with focusing and light box³⁶⁴, code-named OHTEO.

Around 1968, Leitz produced the 24 mm Summar stereo lens on special order for the Israeli government³⁶⁰. This lens, designed to take a pair of 12 × 36 mm photographs, can only be used for static stereo photography, as it must be rotated 180 degrees from position 1 to position 2³⁶⁰. It appears that only one example of this lens has survived³⁶⁰.

The Stemar, considered Leitz's finest contribution to stereo photography, was a remarkable technical achievement³⁶⁰. However, it did not attract a large number of photographers, partly due to its high price and also likely because it was released during a decline in interest in stereo photography³⁶⁰. This explains the limited production of the unit in Midland, Ontario, and its early discontinuation³⁶⁰.

Speculatively, a prism with progressively adjustable shifts might have boosted its popularity³⁶⁰. Nonetheless, Zeiss and Nikon produced nearly identical lenses and setups—Zeiss for their Contax cameras and Nikon for their rangefinder models³⁶⁰. Perhaps the greatest testament to the Stemar is that it was emulated by two of the finest camera manufacturers in the world³⁶⁰.

Photographs and More Information about Stereo Lenses

Illustrated below is 3.5cm f/3.5 Stereo Elmar lens. Only 89 of these lenses were manufactured in Wetzlar between 1940 and 1941, with serial numbers ranging from 541060 to 567100³⁶⁴. They were intended for the paired production of stereo negatives³⁶⁴. The lens features a chrome-plated mount with a large focusing handle and a black front with two adjacent optical elements³⁶⁴. The lens was never included in any brochures and was never officially marketed³⁶⁴.

Illustrated below is the only known example of the prototype stereo lens produced on special order for the Israeli government. The lens was designed to take a pair of 18x24mm photographs by rotating the lens (24mm Summar) through 180 degrees.

Illustrated below is made in 1941 3.5cm f/3.5 Stereo Elmar outfit, that includes the 3.5cm f/3.5 Stereo Elmar lens with serial number 541063 (likely among the 3 of first ever produced), the stereo VIDOM, the OTEMO stereo prism with serial number 5006, 2 original yellow filters for OTEMO, all in the matching and original leather case.

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Illustrated below is 3.5cm f/2.5 Stemar lens. This is the earliest use of the name "Stemar"³⁶⁰.

During World War II, Leitz-Wetzlar produced either the 3.5cm f/3.5 Stereo-Elmar or the 3.5cm f/2.5 Stemar lenses³⁶⁴. Each lens was accompanied by a modified VIDOM viewfinder featuring a fixed 18x24 frame and a pin on the slider, which helped align the lenses horizontally³⁶⁴. For distances ranging from 3 to 10 meters, an adjustable prism attachment (known as OTEMO) was added to the front of the lens for basic extension³⁶⁴. Only 20 units of the 3.5cm f/2.5 Stemar lens were delivered, and a double yellow filter was also provided for the prism attachment³⁶⁴.

For distances greater than 10 meters, a lens cap with a rotatable aperture was utilized³⁶⁴. After taking the first exposure, the cap was rotated 180 degrees, the camera was moved sideways to the required position, and then the second exposure was taken³⁶⁴.

The 3.5cm f/2.5 Stemar serial numbers fall within the 541053 - 582256 range³⁶⁴. Year of production were 1940-1941³⁶⁴.

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Illustrated below is 3.3cm f/3.5 Stemar Wetzlar outfit. The pictured set is definitely an unusual set since most sets were produced at Midland, Ontario³⁶⁰.

In August 1954, Ernst Leitz Canada introduced the 3.3cm f/3.5 Stemar lens³⁶⁴. This lens was available with either a screw thread or a bayonet mount³⁶⁴. It allowed for photography at distances ranging from 1 meter to 3 meters³⁶⁴. Additionally, there was a prismatic attachment called OIMPO, which resembled the Stereoly and increased the distance between the two lenses, enabling shots from 3 meters to infinity³⁶⁴. The package also included a viewfinder with a vertical frame, a special projector, and glasses featuring polarized lenses³⁶⁴.

750 3.3cm f/3.5 Stemar lenses were produced between 1953 and 1954, with serial numbers ranging from 1054001 through 1124550³⁶⁴.