Binoculars Carl Zeiss Jena Telexem 6x (1)

   Binoculars with central focusing appeared on the market in the middle of the 19th century. Carl Zeiss engineers were not in a hurry with such devices’ production, since they considered them less reliable and protected from dust and dirt. First prototypes of these binoculars were produced in Jena back in 1907, but only in 1909/1910 Carl Zeiss was forced to begin mass production of the devices of such design under the competitors’ pressure and because of the demand. First models of central-focus binoculars appeared in T136 catalog in 1910–those were Teletur 6x15, Telexem 6x21, Telactem 8x24 and Silvarem 6x30. Subsequently, all civilian Carl Zeiss binoculars with central focusing had an “...em” ending in their designations.
   The first Telexem models’ objective diameter was equal to 21 mm; since 1911/12 – it was 24 mm, and since 1913/14 the binoculars’ field of view was increased from 6.8° to 8.5°.
   The binocular “civilian” use is proved by central focusing mechanism (military models were never produced with it) and the central hinge clamp’s (fastener’s)small diameter (see photo), which has a hole for a knob (included to binoculars delivery kit), with the help of which the hinge could have been finally fixed depending on the observer’s interpupillary distance. There is an interpupillary distance scale on the upper hinge disc. The right eyepiece has its own focusing mechanism with a diopter scale.
   This device belongs to one of earlier versions (the lens diameter is equal to 24 mm), the lens frame design is of the two-ring type. The eyepieces’ grooves (knurling) are located diagonally (inclined with respect to the eyepieces’ optical axis) and there is no diopter scale on the central focusing flywheel - it appeared on later binocular versions, for example http://binocollection.com/catalog/binoculars-carl-zeiss-jena-telexem-6x.html. The upper prismatic cover width is equal to 45.5 mm, the binoculars height from the lower cut of lens frames to upper prismatic cover is equal to 69 mm. Prism covers are fastened to the housing with the help of three screws. The eyepieces base diameter is equal to 19.5 mm.
   There are inscriptions “Carl Zeiss Jena” on the left prism cover. There is also an inscription “Telexem 277484 6x” on the right prism cover. The inscription is made in block letters with the help of silver solder against the background of Carl Zeiss Tessar photo lens schematic image.
   The device’s serial number is 277484 and it was manufactured in 1912 as a 400 pieces batch.
   The binocular later versions (Telexem) can be checked by the following links: http://binocollection.com/catalog/binoculars-carl-zeiss-jena-telexem-6x.html and http://binocollection.com/catalog/binocular-carl-zeiss-jena-telexem-6x24.html
   Around 1935 Telex was replaced by the new model called Sportur.