Binoculars Carl Zeiss Jena Feldstecher Vergr.=4

Magnification: 4x
Aperture (objective diameter): 14 mm
Field of view: 10.3°
Visible field of view (eyepiece FOV): 41°
The closest focusing distance: 1.5 m
Width: 14.1 cm
Height: 8.5 cm
Weight: 378 g
Production date: 1901.

   It is one of the "oldest" models of Carl Zeiss Jena binoculars. Its objective diameter is 14 mm (earlier models had an aperture equal to 11 mm) and the magnification value is equal to 4x. This model of binoculars had being produced from 1894 to 1908. A little bit less than 4,000 of such devices were released during that period. 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.14-1-115) 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 some data sources - up to 1905) and the mentioned eyepieces’ design was peculiar exclusively to civilian models of binoculars.
   The binoculars frame hinge is attached to its halves with the help of 5 screws from each side (the earlier models were fixed with the help of 4 screws). The upper and lower prism covers are made of brass; 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”, which were fixed with the help of one screw). 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.=4.” – “Binoculars. Magnification=4” on the right prism cover. The inscription is made 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 "965" and upon the binoculars design (eyepieces joint, the frame hinge fixing) one can assume that the binocular was produced approximately in 1901.
   Late version of this binocular model http://binocollection.com/catalog/binoculars-carl-zeiss-jena-feldstecher-4-fach.html