Binoculars Carl Zeiss Jena 15x60 DELFORTEM, "Military", 1938
The Carl Zeiss Jena Delfortem 15×60 is one of the most important high-performance wide-angle binoculars developed by Zeiss on the eve of World War II. Designed as a high-end civilian model, it features the classic Porro I prism configuration and a 15x magnification combined with large 60 mm objectives. With these features, it was the largest Porro I binoculars in Zeiss's civilian program at the time and was designed primarily for long-distance observation.
The most technically interesting aspect of the Delfortem is the combination of high magnification and a subjective field of view of approximately 70°, a particularly wide value for a 15×. This model belongs to the series of large Zeiss wide-angle binoculars of the 1930s, also developed through instruments such as the Deltar and Deltarem 8×40. The Delfortem applied this design philosophy to a binoculars of significantly superior power and aperture, offering a seemingly very large image despite the high magnification.
Factory documentation reveals a rather unusual production history. A first series of 500 units was commissioned in September 1937, while a very rare Zeiss T 637 brochure from October 1938 specifically documents the Delfortem 15x60. A further series of just 6 units appeared in December 1938, while a production run planned for 1939 was subsequently cancelled. The model nevertheless continued to appear in Zeiss documentation: in the 1941 T 700 brochure, it was still presented as a novelty and was also included in the 1943 price list for Switzerland. A final unit was also completed in May 1945, likely during the American occupation of Jena.
The specimens examined lack anti-reflective coating, and some exhibit characteristics that suggest possible military use. A photograph from World War II shows a Kriegsmarine sailor aboard a Schnellboot using large Porro I binoculars very similar to the Delfortem; however, the identification remains speculative and cannot be considered definitive.
The Delfortem 15x60 was therefore a technically very ambitious instrument but was not widely used. Its considerable size, high price, release shortly before the outbreak of war, and apparently limited promotion prevented large-scale production. For these very reasons, it is now considered one of the great rarities of pre-war Zeiss Jena production, as well as one of the last examples of the evolution of the high-performance, wide-angle Porro I civilian binoculars developed by the German company before World War II.
The vision is clear and bright, although the objective lenses have some slight residual staining, likely due to previous mold, which has been professionally removed.
It comes with its original Carl Zeiss Jena case.
References:
Zeiss Handferngläser 1919-1946 di Hans T Seeger: Delfortem 15x60 Pag. 186, 187 e 188.
Carl Zeiss takes its name from its founder, Carl Zeiss, who on November 17, 1846 chose the small city of Jena, in Thuringia, as the location for his precision optical equipment factory.
Thanks to the strict quality control that Carl Zeiss imposed on its products, going so far as to personally destroy the microscopes that did not pass the tests, the newborn Zeiss became the official supplier of the University of Jena and received the gold medal of the industrial exhibition in 1861 of Thuringia as the best research instrument manufactured in Germany, awarded to the microscope Stand I of 1857.
In 1866, the thousandth microscope was produced and the Zeiss name became known in all European scientific circles. Thanks to the studies on the Porro prism, in 1893 Abbe patented a double prism binoculars, which accentuated the perception of depth.
The mass production of Zeiss binoculars began in 1894, already at the beginning of the twentieth century more than 30,000 were made, by the beginning of the First World War the figure had risen to 500,000 and, by the end of the Second World War, 2,260,000 were produced binoculars for the civilian and military market. Models were made starting from 4x11 mm to 12x40 mm, up to real giants such as 80 mm and 100 mm. Thanks to studies conducted on the perception of light in low light situations, it was shown that the average dilation of the pupil in an adult is about 7 mm.
For this reason, the 7x50 mm model was introduced in 1910 and remained on the market until 1917 with few changes to the materials used. In 1926, following the post-war crisis of the First World War with the Treaty of Versailles which bankrupted many important German companies, Zeiss bought the "C.P. GOERZ" and founded the Zeiss Ikon in 1926.
In 1937, Zeiss had commercial contacts and factories spread over 29 countries around the world.
From 1933 Zeiss acquired interest from the Nazi regime, which balanced production towards military instruments. It successfully produced binoculars with wide-angle optics for military use, pressure resistant optical systems for U-boats, periscope binoculars for targeting tanks. Furthermore Zeiss cameras were mounted on the V2 for remote sensing operations of the English coasts.
On November 1, 1935, Zeiss, in the person of Alexander Smakula, patented a process for the treatment of optical glasses with extraordinary results in terms of light transmission. Remained a military secret until 1939, it was adopted on binoculars to reduce ghost images and internal reflections.
During the Second World War, there were numerous bombings against the Zeiss factories. Jena was bombed several times by the Allies starting in 1944. Stuttgart was razed to the ground, although the Contessa-Nettel factory suffered little damage. The bombing of Dresden, in addition to devastating the city, also caused considerable damage to the Zeiss Ikon headquarters.
On April 13, 1945, American military forces entered Jena, surprising themselves as the bombings had not caused significant damage. The main planetarium was in ruins, while the factories remained operational.