Binoculars Carl Zeiss Jena Feldstecher Vergr.=8 (1)

Magnification: 8x
Aperture (objective diameter): 20 mm
Field of view: 4.6°
Visible field of view (eyepiece FOV): 37°
The closest focusing distance: 7 m
Width: 14.1 cm
Height: 10.7 cm
Weight: 437 g
Production date: 1902

   This is the most massive civic binocular among first three Carl Zeiss Jena prismatic models having 4-x, 6-x and 8-x magnification.
   60,000 of such devices were released from 1894 to 1908. Flat prism covers made of brass (the earlier models were made of aluminum) and a central hinge, which is attached to binoculars halves with the help of screws, belong to distinctive features of this model. The civilian application of this model is also 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 “earlier” 4-x and 6-x models have the same fixture design. The interpupillary distances scale is indicated on the upper hinge disk (this scale was absent in earlier models and the disc had a flat shape). This model’s objective diameter is equal to 20 mm (the earlier model had an aperture equal to 18 mm) and 8x magnification. 
   This device possesses eyepieces of the so-called "2/3" transitional design (see Hans T.Seeger. Zeiss-Feldstecher, Handfernglaser von 1894-1919, Modelle-Merkmale-Mythos, pp.114-115) with the base diameter equal to 17.5 mm and the top prism cover width equal to 40 mm. The binoculars with such eyepieces design were produced approximately from the end of 1898 to 1902 (according to other sources – up to 1905) and it was peculiar exceptionally for civil models (see photo). 
   The binoculars frame hinge is attached to its halves with the help of 5 screws from each side. The device has long “lugs” for a jugular strap, which are attached to binoculars with the help of 2 screws (the earlier models had shorter “lugs”). There are inscriptions “Carl Zeiss, Jenna. D.R.P.” on the left prism cover. D.R.P. is an abbreviation for Deutsches Reichs Patent. There is also an inscription “Feldstecher. Vergr.=8.” – “Binoculars. Magnification=8” on the right prism cover. The inscription is encrusted with the help of silver alloy. 
   The continuous serial numbering of Carl Zeiss Jena binoculars was absent at that time (it appeared only at the end of 1907); the new serial numbers were assigned according to the new model release or according to the device design changes. Therefore, relying upon the serial number "17728" and upon the binoculars design (eyepieces joint, the upper hinge disc etc.) one can assume that the binocular was produced approximately in 1902.
   The binocular’s coffer has many peculiarities specific to that period (see Hans T.Seeger. Zeiss Handfernlaser 1919-1946, Modelle-Merkmale-Mythos, pp. 607-627), namely, the design of side belt fasteners, carrying handle on the top cover, the top cover fastening to coffer’s case, specific rivets (see photo).
   The earlier model of this binocular is available by the following link: