Binoculars Carl Zeiss Jena Turact 8x (1)

Magnification: 8x
Aperture (objective diameter): 24 mm
Field of view: 6.3°
Exit pupil diameter: 3 mm
Visible field of view (eyepiece FOV): 50°
The closest focusing distance: 6.5 m
Width: 15.7 cm
Height: 9.8 cm
Weight: 455 g
Production date: 1914.

   In 1912, a very successful Telact 8x model was replaced by Turact 8x. Carl Zeiss decided to make a cheaper binocular, so he simplified the Turact design. The new binocular turned out to be much smaller and lighter, and respectively, more convenient in application. However, its field of view was decreased (from 6.6° to 6.3°) and the aberrations increased. Both binoculars were produced in parallel approximately from 1912 to 1915, and Turact production stopped around the end of 1920s.
   Turact is a “civilian” model; this fact 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. Similar military models are labeled as D.F.8x, D.F.8x24 and D.F.95 n/A.
   Turact was produced with various design changes in 2 versions:
   1st version: with the two-ring type lens frames (starting from 1912 and up to the mid of 1913); and with the eyepieces carcass having the “diagonal” knurling (https://binocollection.com/catalog/binoculars-carl-zeiss-jena-turact-8x.html)
   2nd version: with rounded objective covers (starting from 1913 and up to the end of 1920s) with grooves to minimize stray light and without them;
  This device belongs to a rather rare, second design version, with grooves to minimize side stray flares. It has the eyepieces with base diameter equal to 20.5 mm and the top prismatic cover width equal to 46 mm (see photo). The eyepieces’ front lens diameter is equal to 10.5 mm. The eyepieces have a diopter scale and the diagonal knurling.
   The binocular’s body height (including upper prism cover) is equal to 68.5 mm; this value is equal to 52.5 mm without lens housing. The prism covers are attached to the housing with the help of three screws.
   There are inscriptions “Carl Zeiss Jenna” on the left prism cover. There is also an inscription “Turact 387172 8x” on the right prism cover. The inscription is made in block letters with the help of silver alloy against the background of Carl Zeiss Tessar photo lens schematic image.
   The binocular’s case has features peculiar to that period of time (see Hans T.Seeger. Zeiss Handfernlaser 1919-1946, Modelle-Merkmale-Mythos, pp. 607-627): the self-tightening side belt mounts’ design, the carrying handle on the top cover, the top cover fastening to the case body, specific rivets. The binocular’s case peculiarity consists in the presence of big "military" loops intended for attaching the binocular’s case to the belt. Perhaps, this feature can be considered not as the sign of binocular’s military use, but rather as a peculiarity of that historical period (the First World War beginning – see photo). The kit includes a knob for adjusting the fixing handle. The binocular’s case top cover is of the "seamless" design.
   The binocular’s serial number is "387172" and it was manufactured in 1914. According to Hans T.Seeger. Zeiss-Feldstecher, Handfernglaser von 1894-1919, Modelle-Merkmale-Mythos book, p. 825, it falls into the D.F. 8x batch (serial numbers starting from 387001 and up to 387400), but the previous batch (numbers 386501-387000) was just labeled as Turact 8x. Such situation with serial numbers occurs quite often, since there is no exact information on serial numbers and models of that time, so it requires constant correction.
   The Turact’s "predecessor", namely the Telact model is available by the following link: https://binocollection.com/catalog/binocular-carl-zeiss-jena-telact-8x-1.html
   In 1914 the binocular model with central focusing was released – it was the Turactem 8x model https://binocollection.com/catalog/binoculars-carl-zeiss-jena-turactem-8x-1.html.