Doppelfernrohr 6x30 Voigtländer Braunschweig, Artl. Weimar Republik, around 1920

Doppelfernrohr 6x30 produced by Voigtländer in Braunschweig, in the Weimar Republik period between 1919 and 1933 for the German Navy Artillery.
This binoculars has a "special feature" (Okularhemmung - Ocular Locking System), that distinguishes them from other binoculars used during the First World War, is equipped with a system for memorizing and locking the visual focal length on each individual eyepiece. Therefore, once you have found the focal length, simply rotate the knurled ring on the eyepiece tube and position it on "0". This is a mechanical pre-setting, very advanced for that time, which allowed the focus to be locked at a pre-established point.
The binoculars work in all its mechanisms. Clear vision but slightly out of collimation.

Voigtländer Braunschweig was created in Vienna in 1756, the company took its name from its founder, Johann Christoph Voigtländer and initially produced optical instruments, intended in particular for microscopes and other scientific equipment. Among the first creations were the Petzval type lenses, and others destined to become famous, such as the Collinear and the Heliar.

In 1840 he built the first lens for cameras, while in 1841 the first entirely metal daguerreotype was developed. He subsequently produced plate machines, built in a practically artisanal way.

In 1849 the headquarters were moved to Braunschweig, Germany, where Voigtländer & Sohn was born shortly thereafter.

In 1925 it was purchased by Schering AG. Voigtländer later oriented its production towards photographic devices accessible to all, and this allowed it to remain among the market leaders until after the Second World War. In 1958 it was bought by the Carl Zeiss Foundation and in 1972 it was renamed "Zeiss Ikon Voigtländer". In 1973 the brand became the property of Rollei until the crisis of 1982.

At this point the brand was bought first by "Plus foto", which from 1980 marketed Voigtländer cameras produced by Ricoh and Chinon and then in 1995 by "Ringfoto", but this represents more than anything else a long period of darkness. Finally in 1999 the brand was reborn with the purchase by the Japanese Cosina.