German Precision Optical Products
The German optical industry has long been world famous for producing superb optical instruments, and German optical companies like Carl Zeiss, Ernst Leitz, Emil Busch, M. Hensoldt and others are world renowned as market leaders in the development and manufacturing of precision optical products.
At the outbreak of World War II in September 1939, these and many other precision optical manufacturing companies rapidly put all their vast expertise and technical proficiency into the production high quality military optical equipment for the German armed forces, with a wide range of range of optical observation devices employed by all services during the war.
Because of the exceptionally high quality of German optical equipment, German precision optical products were widely used and produced under license by many other countries before, during, and after the war.
In the early years of the German conquest of Europe, Germany invaded and took over many other countries, and quickly incorporated foreign optical manufacturing companies like Swarovsky of Austria, Ungarnische Optische Werke of Hungary, Srb & Stys, Fabrik praeziser Messinstrumente, Prague, Czechoslovakia, Huet et Cie of France, and other companies of the conquered nations’ optical industries into war production for the German armed forces.
Optical Equipment Cold Resistant Grease
The beginning of World War II in September 1939, and the subsequent shortage of petroleum stocks in Germany, sparked intense German interest in the development of synthetic petroleum lubricants. Germany’s disaster in the Battle of Stalingrad (August 1942 – February 1943) demonstrated the inadequacy of existing petroleum products in extremely cold weather. Because the petroleum lubricants used in tanks, aircraft, and other military vehicles gelled, the engines of these vehicles could not be started.
Immediately, an emergency research effort got underway to find alternative lubricants, which led to the first experimentation and manufacture of synthetic petroleum products to be used by the German armed forces.
The extreme stress of intense, brutal warfare conducted in bitterly cold winter weather on the Ostfront demonstrated the inadequacy of the petroleum grease used in German military and naval optical equipment. The German chemical industry developed several types of cold resistant greases for use in the optical equipment of the German armed forces.
In response to German experience with extraordinarily cold temperatures on the Eastern front, improvements in the development of cold resistant lubricants began about May 1940 and continued throughout the war.
As war on the Ostfront progressed from 1941 to 1943, the bitter cold of the Russian winters continued to reveal the inadequacy of the grease used in German optical equipment.
Optical equipment special synthetic cold resistant greases were developed to make it possible for German optical equipment to function in the bitterly cold extremes of Russian winters.
KF : 1940-1941
O : 1942
+ : 1942-1943 (mainly applied in 1943)
Δ : 1944-45 (mainly applied in 1944)
KF : 1940-1941
KF : Kälte Fett – cold resistant grease “Invarol” – weißer Schrift (white letters) “KF” or “K.F.” 1940-1941
The earliest cold resistant grease used in German optical equipment was introduced about May 1940 when the cold resistant grease “Invarol” became available. The white letters “KF” for Kälte Fett (literally “cold fat” – cold resistant grease) began to be marked on German optical equipment assembled with “Invarol” to certify that the grease was tested to properly operate equipment in temperatures as low as -20 degrees Celsius (-20 °C) = -4 degrees Fahrenheit (-4 °F).
O : 1942
O : Vakuumfett 1416 – cold resistant grease “Vacuum” – hellblaue Kreis (light blue circle) “O” 1942
Following the German Army’s experience during the Russian winter of 1941, the cold resistant grease “Invarol” was found to be inadequate, and was updated about mid-1942 to a new cold resistant grease called Vakuumfett 1416 (“Vacuum”). The symbol of a light blue circle “O” (hellblaue Kreis) was marked on German optical equipment assembled with “Vacuum” to certify that the grease was tested to properly operate equipment in temperatures as low as -40 degrees Celsius (-40 °C) = -40 degrees Fahrenheit (-40 °F). The light blue circle “O” symbol was first mentioned in the German manual for winter warfare (“Taschenbuch für den Winterkrieg“), dated August 5, 1942.
+ : 1942-1943 (mainly applied in 1943)
+ : Instrumentenfett 1442 – cold resistant grease “Instrument Grease 1442” – hellblaue Kreuz (light blue cross) “+” 1942-1943 (mainly applied in 1943)
The new Vakuumfett 1416 quickly proved unsatisfactory, and a new cold resistant grease called “Instrument Grease 1442” was introduced. The symbol of a light blue cross “+” (hellblaue Kreuz) was marked on German optical equipment assembled with the improved “Instrument Grease 1442” to certify that the grease was tested to properly operate equipment in temperatures as low as -40 degrees Celsius (-40 °C) = -40 degrees Fahrenheit (-40 °F). The revised edition of the German manual for winter warfare (“Taschenbuch für den Winterkrieg“) was published November 1, 1942, just three months after the previous edition of August 5, 1942. The manual stated that “in the future, all observation and surveying instruments of the Army will be lubricated only with instrument grease 1442.” (“in Zukunft wird das gesamte Beobachtungs und Vermessungsgerät des Heeres nur mit Instrumentenfett 1442 gefettet.”)
“gerate die eine ausgelegate hellblaue kreisflache tragen mit Batuumett 1416 oder einem Fett mit gleichen kalteeigenfchaften gefettet. Diefe gerate find bis -40 c einwandfrei bedienbar.”
Δ : 1943-1945 (mainly applied in 1944)
Δ : unknown – cold resistant grease – hellblaue Dreieck (light blue triangle “Δ”) 1944-1945 (mainly applied in 1944)
Little information is known about the final version of cold resistant grease used in German optical equipment during the last years of World War II. The name of the grease and its cold resistant properties are not known. The symbol of a light blue triangle “Δ” (hellblaue Dreieck), usually with the triangle body completely filled in with light blue paint, appeared in late 1943, and was marked on German optical equipment assembled with the final version of cold resistant optical equipment grease to certify that the grease was tested to properly operate equipment in temperatures as low as -40 to -50 degrees Celsius (-40 to -50 °C) = -40 to -50 degrees Fahrenheit (-40 to -58 °F).
The presence of the symbols KF, O, +, and Δ on German optical equipment of World War II signifies that a series of special cold resistant greases were used in the final assembly process of German optical equipment to permit German optical equipment to operate efficiently in extreme cold weather conditions.
Because the various cold resistant lubricant symbols appeared in successive years, as improvements in lubricant performance and availability progressed throughout the war, the symbols help to provide a reasonable estimate of year of manufacture and year of return to the manufacturer for repair or maintenance. However, the dates are not perfect indicators, since manufacturers changed from using older symbols to newer symbols as existing stocks of cold resistant lubricants ran out and new improved lubricants arrived for use at the factories.
Optical equipment already in service with field units was returned to the manufacturer or a supply depot for repair or maintenance, and to have the latest cold weather resistant lubricants applied. A new symbol was added to a previous symbol when the instrument was returned for repair, maintenance, and regreasing. It is typical to see German optical equipment with two or more cold resistant lubricant markings applied to the same instrument. Understanding the sequence in which these markings were approved for use makes it possible to tell which marking may be original to the equipment at the time of manufacture, and which markings were added in successive years for maintenance, repair, and regreasing.
Most optical equipment was not explicitly dated, but it is possible to estimate the year of manufacture, based on the style, maker, design, manufacturing materials, and paint color of the equipment. Fortunately, optical equipment made by Carl Zeiss is marked with serial numbers that identify the year of manufacture.
Optical equipment manufacturing materials and techniques changed over the course of the war. Most pre-war optical instruments were made using higher quality materials, such as brass and bronze. As access to these higher quality raw materials diminished in the later war years, lesser quality alternative metals, such as low carbon extruded steel, soft cast zinc alloys, and Presstoff (Bakelite), were used in the manufacture of optical equipment.
German optical equipment manufacturers codes
About 1940, German optical equipment manufacturers were identified by a three letter code marked on the body of the optical instrument. For example, the optical manufacturer code “ccx” identifies the manufacturer as “Optische und Feinmechanische Werke” of Hugo Meyer & Co, Görlitz, Germany. Other examples of manufacturers codes marked on German military and naval optical equipment include “beh” (“Ernst Leitz” of Wetzlar, Germany), “cag” (“D. Swarovski” of Wattens, Tirol, Austria), “gug” (“Ungarnische Optische Werke of Budapest, Hungary”), and “lww” (“Huet et Cie” of Paris, France).
Doppelfernrohr – (Dienstglas 6 x 30 Service Glasses)
The German army used an extensive array of optical equipment during the war, such as the 6×30 Dienstglas (service glass) binoculars with 6 power magnification and 30mm diameter objective light gathering lens, that were the standard issue field optics used by all branches of the armed forces. These are generally encountered in a black painted finish and were typically constructed of zinc and aluminium alloy metal. Beginning in 1943, late war Dienstglas were manufactured with a tan painted finish called Sandgelb (sand yellow) often fitted with moulded brown or black Presstoff (Bakelite) lens fittings. Some very late war 6×30 Dienstglas bodies were even manufactured entirely of Presstoff (Bakelite). In the later war years, other types of optical equipment were also manufactured with the regulation Sandgelb (sand yellow) painted finish.
Often built into the right lens of German binoculars was a Strichplatte (reticle), a horizontal range finding scale measured in millimeters, with vertical lines extending from the center to each side in increments of 10 mils to 40 mils. German Dienstglas that have the range finding scale built into the right lens are marked in weißer Schrift (white letters) on the right prism cover with “m” or “M” (indicating millimeters) followed by “H/6400” (indicating that the millimeter scale is graduated into 6400 segments measured in mils).
Between 1938 and 1939, the “m” or “M” was discontinued, and only the “H/6400” was retained to show that a Strichplatte (reticle) range finding scale was built into a particular Dienstglas. The “m” or “M” preceding “H/6400” is often confused with the capital letter “M” marked beneath or near the Nazi Eagle symbol that identifies property of the German Marine (Navy).
Dienstglas 6×30 standard markings on the left prism cover usually include the manufacturer logo (up to 1940) or the manufacturer three letter code (beginning in 1940). On the right prism cover, standard markings usually include the designation “Dienstglas” over “6×30” over the production serial number over the “m” or “M” (up to 1939) followed by “H/6400” if the Dienstglas has a range finding scale.
Most service glasses were finished in either a leather or moulded Bakelite case to afford maximum protection during service life. Since the 6×30 power binoculars were of a relatively low magnification being well-intentioned for just general field observations, specialized troops such as Kriegsmarine, Artillery observers, Reconnaissance personnel, Flak & Searchlight personnel etc required far stronger optics and assorted larger more powerful binoculars were issued to these specialized personnel on a limited basis.
Black leather or “Vulkanite” (a synthetic, leather-like, early form of plastic) was used as a body covering on Dienstglas manufactured before World War II. Later, a black “rice” body covering (black paint mixed with crushed rice to give a rough body texture) also became a common Dienstglas body finish.
As wartime material shortages and minimal manufacturing techniques went into effect, paint alone eventually became the last Dienstglas body covering, including dark gray paint and Sandgelb (sand yellow) paint.
Sandgelb was ordered to be used on new optical equipment made after September 1943, and existing optics were also ordered to be repainted with the new sand yellow color.
Sellers on eBay often erroneously claim the Sandgelb sand yellow color to be somehow related to the German Afrika Korps.
Doppelfernrohr – Dienstglas 10×50 Service Glasses
In 1934, the German OKW, Oberkommando der Wehrmacht, (High Command of the Armed Forces), requested a mobile, multi-purpose, high power binocular with a wide field of vision. The Emil Busch optical firm of Rathenow submitted a 10×50 power binocular that was accepted for production. The 10×50 power binoculars were produced by several optical firms in three minor variants with the main difference being in the angle alignment of the prism and ocular lenses with a 20 degree angle pattern, a 45 degree angle pattern, and an 80 degree angle pattern.
This set is stamped ‘blc’, indicating that they were manufactured by Carl Zeiss.
Doppelfernrohr 10 x 80 Flakfernrohr
In 1935, several companies, including Emil Busch, Leitz, and Möller, competed for a Wehrmacht contract to produce a 10 power binocular for aircraft observation. In 1936, Emil Busch AG of Rathenow won the contract with their design chosen for its lighter weight and wider field of view over the models by Möller and Leitz. Full production by Busch began almost immediately, and continued throughout the war.
The Busch design was also produced by other firms in Germany and occupied Europe, with all models using identical optical dimensions of 80mm cemented achromatic objectives, 280mm focal length, 70 degree eyepieces, and 45 degree Schmidt roof prisms. Some differ only in coated lens or other minor details.
Characteristic markings found on the body of these glasses always include a large “D.F.” which stands for Doppelfernrohr and means double telescope. Other markings usually refer to the particular factory that made them, with only the early Busch models having the manufacturer’s name.
After 1942, models carry the three letter manufacturer code; beh (E. Leitz, Wetzlar), dkl (Schneider, Bad Kreuznach), cro (R. Fuess, Berlin Steglitz), bpd (C.P. Goerz, Vienna), eug (Optische Präzisions-Werke, Warsaw) or cxn (E. Busch, Rathenow).
Many models also carry markings indicating use for extreme weather conditions as mentioned in the earlier text (see above). They came with an array of extra’s including an aiming sight, mounting cradle, rubber padded eyebrow cushion, rain shields, elevation drums, heavy tripod, spirit levels, filters and a protective wooden storage case.
The 10 x 80s were primarily used by Luftwaffe Flak Artillery ground crews for spotting and identifying enemy aircraft and directing the crew served Rangefinders, Searchlights and Flak Cannons of the Anti-Aircraft batteries based around many German cities and industrial centres. Naturally they also proved useful on the battlefield for tactical observation and a version with 20-deg inclined eyepieces was also produced for the Kriegsmarine at sea. A single half of the 10 x 80 binocular can also be encountered and was used as a sight for the 8.8cm artillery, referred to as Z.F. (Zielfernrohr) 10 x 80.
When using any artillery or anti-aircraft guns effectively, accurately estimating range to the target is critical to the success of a direct hit on the target. Many armies around the world employed optical equipment specially designed for range finding and although most looked very similar in design, two schools of thought existed with one type working on the theory of coincidence and the other being a stereoscopic based vision system. The German’s like most other armies favoured the coincidence of images principal. These Rangefinders using this coincidence theory work on the known principal of triangulation were by knowing the distance between two points which we call the base line (i.e. the two objective lens being 1000mm apart in the device) and the angle of these two points relative to the target, one can work out the distance by using trigonometry.
In the R36 this calculation is worked out with a very complicated internal mechanical computer which reads out the data using dials and a split overlaid image reticule seen through the view finder which the viewer matches up and reads off the scale the distance to target. However to do this the operator must have extremely good eye sight to accomplish this accurately so candidates must be evaluated for suitability first. Worth remembering also is that the bigger the baseline the more precise the ranging is and to this end Germans employed range finding equipment frequently up to 4 metres in length specially developed for coastal and anti-aircraft batteries because of the typically large distances involved ranging ships and high altitude aircraft. Naturally of course the limitations of accuracy reached are often dictated by air quality and weather conditions and then ultimately the curvature of the earth.
The Scherenfernrohr S.F.14.Z.Gi.
1894 saw the famous German optics firm of Carl Zeiss introduce a new and unusual type of prism binoculars. Zeiss called its invention the Scherenfernrohr (scissors telescope) an 8 x 10 power device fitted with adjustable twin periscopic extensions connected by a hinge. An observer could position the tubular “ears” upright and parallel to each other or splayed out horizontally for greater depth perception (stereoscopic vision), causing objects to appear in modelled relief, strongly distinct from the background and thus estimate the range.
This hybrid between binoculars and a periscope enabled the observer to remain safely concealed in dug outs, behind walls or even tree trunks with only the objective lens visible to the enemy. 1905 saw the design refined further with an army-issue variant and a field artillery model being trialled and adopted. Naturally other countries produced their own versions of the scissors telescope and when World War I broke out both opposing armies all along the Western Front observed each other from their trenches using such equipment. By World War II the design remained virtually unchanged except for an upgrade in magnification to 10 x 50 and continued to be a useful tool in the Wehrmacht for general observation (in both vehicles and on the ground) and for artillery fire observation and direction throughout the war. Oddly the post-war West German Bundeswehr never use the Scherenfernrohr device at all, but East Germany’s Nationale Volksarmee and other Warsaw-pact countries including Russia continued to do so long after the war ended.
According to “Der Artillerist, (1) Der Kanonier (1940) the SF was to be used for:
1) Observation and reconnaissance
2) Measuring angles of azimuth
3) Measuring angles of site and elevation
4) Measuring height of shell bursts
5) Establishing safety zones for advancing friendly troops
6) And to lay field guns.
To aid ground infantry and artillery observers the Scherenfernrohr was used in conjunction with a tripod leg assembly. It normally came with accessories such as the azimuth mount and spirit level, tripod, carrying case, and other items such as a battery powered removable illumination lamp kit and a trench mount (often referred to as a tree screw which was approximate to a sort of cork screw that could allow the mount to be imbedded in wood or the ground).
The Scherenfernrohr S.F.14.Z.Gi was often seen employed in different roles such as in vehicles being specifically delivered as standard equipment in many German armoured fighting vehicles such as the StuG III, Jagdpanzer IV, Panther and on the King Tiger where it can often be seen poking out the commanders cupola primarily as a safe method for him to observe the enemy without risk to life.
Most if not all Scherenfernrohr’s came equipped with a reticule grid pattern and were designated as such in their markings found on the base of the right tube as ‘S.F. 14Z G.i.’. The G.i. meaning “Gitterplatte” (Grid Pattern). This can apply to models with either the grid or rarer L-shaped style reticule pattern. This grid pattern feature is used for ranging using lines graduated at 10 mil intervals where the H/6400 is a common artillery scale used by the Wehrmacht where the ‘H’ stands for Heer.
Also pictured is the Gestell 31 tripod, battery box, rain / sun shields and the spanner / screwdriver.
Sfl.Z.F.1a Selbstfahrlafetten-Zielfernrohr
Featured here along with its transit case is a classic example of the periscope style Sfl.Z.F. 1a (Selbstfahrlafetten-Zielfernrohr) main gun sight used for armoured fighting vehicles such as the StuG III and StuG IV. It was also successfully employed on the Hetzer, Jagdpanzer IV/70 SdKfz.234 8 Rad Armoured Car and the Sturmpanzer IV (otherwise known as the Brummbär). The reticule had a magnification 5x with 10° of vision, the reticule aim pattern consisted of 7 triangles laid in a horizontal row, each separated by 4 mils. Placing the target on the point of a triangle allowed the gunner to aim without obstructing his view of the target. The distances between triangles were used to lead moving targets. The triangle height and separation distances in mils were also used as an aid in estimating the range to a target. The sight was mounted to the left of the main gun with the head just protruding through the roof of the armoured superstructure which can be often seen in many original pictures as being the case.