Binoculars Carl Zeiss Jena E.I. (D.F.8x)

   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).
   Earlier, around the end of 1906, first military versions of D.F. 8x binoculars appeared in the new design (an old version is available by the following link - https://binocollection.com/ru/catalog/binokl-carl-zeiss-jena-df8x.html). These were the analogs of the “civil” Telact 8x model that appeared a little bit later (https://binocollection.com/ru/catalog/binokl-carl-zeiss-jena-telact-8x.html). The earliest D.F. 8x devices had their own individual number and they were intended for sale to military people in private order with the permission of military department (for example, the D.F. 6x binocular has the same number - https://binocollection.com/ru/catalog/binokl-carl-zeiss-jena-df6h-1.html. This model was produced with such marking for a very short time. Later, the serial numbers were shifted to the lower right prism cover edge and they started to put military approval number on the upper right prism cover (under the name of the model).
   The binoculars, which are presented in our virtual museum today, are a complete analogue of the military binoculars D.F.8x in the Telact design https://binocollection.com/catalog/binoculars-carl-zeiss-jena-df8x-1.html . This is the 2nd version of the device: with two-ring type objective lens frames (produced from 1908 to 1913). The "military" use of the binoculars is indicated by the large diameter of the central hinge clamp, the presence of a rangefinder grid and elements of the case design (see photo).
   The diameter of the eyepiece base is 24.5 mm, the width of the upper prism cover is 50 mm (see photo). The eyepieces have a diopter scale, transverse (perpendicular) knurling. The height of the binocular body (including the upper prism cover) is 80 mm.
   The most interesting thing about this device is its marking. The «Carl Zeiss Jena» logo is on the right prism cover: export devices were often marked this way. "244" is most likely a batch number or military acceptance. But the most mysterious marking is "E.I". To this day, there is no generally accepted explanation for this abbreviation. One version points to the "Italian" origin of this inscription: "E.I" - Esercito Italiano (Italian army). However, opponents of this version refer to the fact that such marking appeared only in 1946, and this binocular was released in 1910. Perhaps the left prism cover was replaced later (such replacement was practiced), but the writing style and marking technology indicate that both covers were made at the same time. In addition, the serial number "225504" (on the edge of the front right prism cover) clearly indicates the end of 1910, the beginning of 1911, which coincides with the marking on the left prism cover - "1910". According to Hans Seeger (see Hans T.Seeger. Zeiss-Feldstecher, Handfernglaser von 1894-1919, Modelle-Merkmale-Mythos, p.810) this binocular is in a batch of 400 pieces with a range of serial numbers from 225504 to 225301. It is noteworthy that this model is marked in the book as unknown.
   There are also versions of the "Swedish" and "Danish" origin of this device, but they are less plausible.
   The coffer for these binoculars is well preserved. It has attributes of military use: a working compass on the top cover, a wide loop for attaching to a waist belt. The top cover is made using seamless technology, the design of the rivets corresponds to that time. There is no doubt that the coffer belongs to this binoculars.
    At the moment, three copies of this interesting device are known. If any of the collectors has similar binoculars, we ask you to inform us by e-mail.