Binoculars Carl Zeiss Jena Silvamar 6x

Magnification: 6x
Aperture (objective diameter): 30 mm
Field of view: 8.4°
Exit pupil diameter: 5 mm
Visible field of view (eyepiece FOV): 50°
The closest focusing distance: 4.5 m
Width: 16.8 cm
Height: 12 cm
Weight: 658 g
Production date: 1910/11.

   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. 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. Actually, the binoculars have survived in such appearance up to present days (see Hans T.Seeger. Zeiss-Feldstecher, Handfernglaser von 1894-1919, Modelle-Merkmale-Mythos, pp.399-414)
  Silvamar is the first binocular model having 30 mm lenses. The device turned out to be very successful, characterized by high aperture, plasticity and wide field of view, and therefore it became the “champion” in terms of production time: Silvamar was produced from 1907 up to 1969 with various changes. It is a “civilian” model; similar military versions are marked as D.F.6x30 and Marineglas 6x(30).
   The “civilian” application of this model is proved by the central hinge fixture’s (clamp’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. The interpupillary distances scale is indicated on the upper hinge disk.
   The design of this rare binocular specimen is characterized by short housing and long two-ring type lens frames, which were produced in a short period of time, namely from 1909 to 1910/11.
   This device possesses eyepieces of the so-called "1/3" design (see Hans T.Seeger. Zeiss-Feldstecher, Handfernglaser von 1894-1919, Modelle-Merkmale-Mythos, p.117) with the base diameter equal to 24.5 mm and the top prism cover width equal to 52 mm (see photo). The eyepieces possess a diopter scale and a transverse knurling. The binoculars’ case height (including upper prism cover) is equal to 55 mm.
   There are inscriptions “Carl Zeiss Jenna” on the left prism cover. There is also an inscription “Silvamar 227084 8x” on the right prism cover. The inscription is encrusted with the help of silver alloy and is made in block letters against the background of Carl Zeiss Tessar photo lens schematic image. Prism covers are attached to the housing with the help of three screws.
   The binocular’s coffer has peculiarities specific to that period (see Hans T.Seeger. Zeiss Handfernlaser 1919-1946, Modelle-Merkmale-Mythos, pp. 607-627), namely, carrying handle on the top cover, the top cover fastening to coffer’s case, specific rivets (see photo). There is a crank, included to the kit and designed to adjust the fixing knob. The coffer upper cover is of the “seamless” design.
   The binocular’s serial number is “227084” and it was manufactured in 1910/11. However, there is a discrepancy with the facts from the book by Hans T.Seeger - Zeiss Handfernlaser 1919-1946, Modelle-Merkmale-Mythos, p.810 – the binocular belongs to the range of Marineglas model serial numbers. Perhaps, the serial number was assigned earlier, and the binocular itself was manufactured later.
   The binocular military analogues - Marineglas and D.F.6x30 models can be checked here: (link)
   Later versions of Silvamar 6x(30) binoculars with other lens frames’, eyepieces’ and housings’ designs can be checked here:
The binocular model with central focusing, namely Silvarem 6x, was released in 1909: