Doppelfernrohr Revolver Carl Zeiss ASEMBI, Kriegsmarine, circa 1910/1935

Doppelfernrohr or Double Telescope model "ASEMBI" Military version made by Carl Zeiss starting from 1910, complete with its original "Richtkreis" base, equipped with micrometric zenith and azimuth movement, as well as its original tripod.

This extraordinary double telescope was built mainly in solid iron as this feature was considered a necessary requirement to be able to withstand the shocks of the very strong explosions caused by the batteries of the powerful guns on board battleships and heavy cruisers as, some versions with "deck mounted" attachment, were installed on the decks of German warships.

After being used in the service of the Kaiserliche Marine during the First World War, its structural characteristics as well as the provision of extremely versatile trinocular turrets in the face of various conditions of observation needs, allowed the high commands of the "Vorläufige Reichsmarine" to reassign it to the "Reichsmarine" of the Weimar Republic which immediately found itself facing the heavy restrictions provided for by the "Treaty of Versailles" in which the allied states imposed on Germany a drastic reduction in the production of war material such as weapons, optics, equipment, technical instruments, etc. etc. to be allocated to the armed forces. Therefore, to circumvent these limitations, the high commands of the "Vorläufige Reichsmarine" decided to reuse material already existing and produced before these restrictions, reassigning it to the armed forces serving the "Weimar Republic".

In light of this, therefore, a plate affixed to the right eyepiece tube bearing the "Reichsadler" in use by the "Reichsmarine" from 1918 to 1935 and the "N" followed by an "X" number, attributable to the assignment to one of the units active and operating in the "Nordsee" (North Sea) under the control of the "Marinestation der Nordsee der Reichsmarine", certifies its reuse well beyond the First World War. Its optical equipment is composed of two triocular turrets respectively 12x, 20x, and 40x with orthoscopic eyepieces, or triplets, suitable for brighter focal ratios, with an excellent reduction of aberrations but above all of distortions; these, combined with the 80mm objectives, were considered the best for the optical properties available at that time and allowed the observer to view incredibly bright and well-defined images.

Two small "release levers", located near the turrets, allowed to lock or unlock the rotation on the chosen focal magnification. In addition, the interpupillary aperture of the eyepieces, obtained by rotating the two turrets to the maximum distance, was arranged in such a way as to allow the use of the binoculars even by two observers at the same time.

It is equipped with its original "Richtkreis", equipped with micrometric movements, which is also equipped with a "quick release" lever of the rotation which allows, in particular conditions of need, to freely rotate the Asembi doppelfernrohr 360°.

Its original extendable tripod, light but extremely resistant, provides truly excellent stability even on not entirely regular terrain.

Its extraordinary technological innovations for the time will make it become an optical-mechanical excellence still unsurpassed today if compared to the era in which it was produced.

The binoculars are in excellent aesthetic and functional conditions, all the mechanisms move correctly and are perfectly collimated.

Carl Zeiss takes its name from its founder, Carl Zeiss, who on November 17, 1846 chose the small town of Jena, in Thuringia, as the location for his precision optical equipment factory. Thanks to the severe quality control that Carl Zeiss imposed on his products, going so far as to personally destroy the microscopes that did not pass the tests, the newly formed 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 produced in Germany, awarded to the Stand I microscope of 1857.

In 1866 the thousandth microscope was produced and the name Zeiss became known throughout European scientific circles. Thanks to studies on the Porro prism, in 1893 Abbe patented 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, at the beginning of the First World War the quota had risen to 500,000 and, at the end of the Second World War, as many as 2,260,000 were produced binoculars for the civil and military market.

Models were made starting from 4x11 mm to 12x40 mm, up to real giants such as the 80 mm and 100 mm. Thanks to studies conducted on the perception of light in low light situations, it was demonstrated that the average dilation of the pupil in an adult is approximately 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 purchased "C.P. GOERZ" and founded Zeiss Ikon in 1926.

In 1937 Zeiss had commercial contacts and factories in more than 29 countries around the world. From '33 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 V2s for remote sensing operations of the English coasts.

On 1 November 1935, Zeiss, in the figure of Alexander Smakula, patented a process for the treatment of optical glass 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 that the bombing had not caused any significant damage. The main planetarium was in ruins, while the factories remained operational.