Binoculars Carl Zeiss Jena Telex 6x24

Magnification: 6x
Aperture (objective diameter): 24 mm
Field of view: 8.5 °
Outlet pupil diameter: 4 mm
Visible field of view (eyepiece): 51 °
The closest focusing distance: 4 m
Width: 15.5 cm
Height: 11 cm
Weight: 480 g
Production date: 1931.

   In 1907, Carl Zeiss radically changed the framework and the design of his binoculars, replacing "civilian" models Feldstecher 6 Fach by Telex, Feldstecher 8 Fach by Telact, Jagdglas by Silvamar and Feldstecher 12 Fach by Telefort. The new devices’ detailed characteristics were published in the 74-th volume of Carl Zeiss catalog in August 1907. However, there are facts indicating that the new models’ sale started a little bit earlier than this date.
   The optical characteristics were significantly improved in new devices (the field of view and the objective diameter were increased, optical aberrations were decreased), and the devices’ design was also changed: the central hinge and the “lugs” for a neck strap were not attached to binocular with the help of screws any more, they became integral with it instead, an eccentric objective alignment system appeared and its frame design was also changed, the prism covers spanned the binoculars’ carcass, and they were lubricated with a special compound at the joint points in order to improve impermeability. Moreover, the prisms inside the binoculars were no longer pressed by prism covers – they were fixed with the help of special flat springs instead. It helped increasing the device’s reliability greatly. The serial numbers acquired continuous numbering, regardless of the model, and from then on they were placed on prismatic covers (on side surfaces, or on the upper right cover), but some time later serial numbers were shifted to the front hinge washer. Actually, the binoculars have survived in such appearance up to present days. 
   Telex is the smallest model with a new design, 6x magnification and 24mm lens in the latest version. D.F.6x24 model is its military analogue.
   Telex was produced in 4 versions with various design changes until 1932: 
   1st version: 6x21, in which the cap of frame lens and the lower prismatic cover were made as a single part (since 1907) and the eyepiece case had the “transverse” knurling (see photo) ;
   2nd version: 6x21 with the two-ring type lens frames (since 1908/1909) ;
   3rd version: 6x24 with the two-ring type lens frames (since 1911/1912) ;
   4th version: 6x24 with the rounded lens covers (from 1913 to 1932);
   This device belongs to the latest, 4th version, with rounded lens covers. The eyepieces’ grooves (knurling) are now located along the binocular optical axis. The eyepieces possess the diopter scale for adjusting the acutance. The width of the upper prismatic cover is 50.5 mm; the binoculars height from the lower cut of lens frames to upper prismatic cover is equal to 71 mm. The eyepieces base diameter is equal to 24.5 mm. This binocular has an increased field of view compared to previous versions (it is equal to 8.5° instead of 6.8°). 
   There are inscriptions "Carl Zeiss Jena" on the left prism cover. There is also an inscription "Telex 6x24" on the right prism cover. The inscription is made in block letters against the background of Carl Zeiss Tessar photo lens schematic image (the earlier models had an inscription in italics until 1904).The serial number of this Telex model is located on the front hinge washer. The interpupillary distance scale is placed on the upper hinge disc. 
   The binocular’s case has peculiarities specific to civilian models of that period (see Hans T.Seeger. Zeiss Handfernlaser 1919-1946, Modelle-Merkmale-Mythos, pp. 607-627).There is an embossing in the form of logo “Carl Zeiss Jenna” and the inscriptions “Made in Germany” on the upper part of the lower case half.
   The binocular and its case have survived perfectly well and they have almost no signs of utilization.The binocular’s serial number is “1585276” and it was released as a 400 pieces batch in 1931.
   Previous version of this model is here
   The first version of this model is here
   Approximately in 1935 Telex was replaced by the new model called Sportur.