Henryk Kolberg, 1937-1939
6×30 Production Serial Number Series

Rzeczpospolita Polska, Republic of Poland, 1919-1927

Rzeczpospolita Polska, Republic of Poland, 1928-1939

Carl Zeiss (rln), Jena, Thuringia, Germany, 1943-1945

In the German armed forces, Doppelfernrohr (binoculars) were marked with the word Dienstglas (service glass) to identify them as government military property.

A Dientglas was issued to soldiers with specialized functions. For example, a Gruppenführer (group leader), or an Artilleriebeobachter (artillery observer), was issued a Dienstglas to perform his duties.

The most common type of service glass was the 6×30 Dienstglas, based on the 6×30 Carl Zeiss Silvamar, introduced in 1910. The 6×30 Silvamar was light weight, 365 grams after 1935. Production of the 6×30 Silvamar was eventualy halted around 1975.

The number “6” identifies the magnification power (in this case, “6” indicates that objects appear six times closer than their actual distance).

The number “30” identifies the diameter in millimeters of the front (objective) lenses — the light gathering lenses — in this case 30 millimeters in diameter.

Another type of service glass used by the armed forces of Germany during the Second World War was the 8×30, based on the 8×30 Carl Zeiss Deltrentis, that first appeared in 1920.

The body was made of magnesium and was featherlight at just 390 grams. The wideangle eyepieces, designed by Albert Koenig, were free of distortion and contained 4 lens-elements. A single layer anti-reflection coating with a bluish color was first added during the Second World War. Production of the 8×30 Deltrentis was eventualy halted around 1995.

The number “8” identifies the magnification power (in this case, “8” indicates that objects appear eight times closer than their actual distance).

From November 1940, German military service binoculars were marked with a three-digit letter code to protect the location of manufacturers’ factories from Allied bombing.

Military service binoculars manufactured by Carl Zeiss Jena were initially coded “blc” in November 1940. The later “rln” code seems to have been introduced in early 1943.

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“O” Kältefettmarkierungen (cold resistant grease marking)

“O” (1942)
marked with a hellblaue Kreisfläche (light blue circle) “O”
introduced before August 5, 1942

“O” — kältebeständiges Fett (cold resistant grease) — “Vakuumfett 1416” (“Vaccuum Grease 1416”), also known simply as “Vacuum” — marked with a hellblaue Kreis (light blue circle) “O” on Dienstgläser (Service glasses) manufactured (or returned to a support facility for maintenance, repair, or regreasing) during 1942.

According to Allgemeine Heeresmitteilungen (General Army Releases), the cold resistant grease “Vakuumfett 1416” was introduced no later than January 26, 1942, and was certified to be fully operational for use on equipment to -40° Celsius (-40° Fahrenheit).

The earliest document referring to “Vakuumfett 1416” — “O” — was the German Taschenbuch für den Winterkrieg (Manual for Winter Warfare), first version dated August 5, 1942.

“+” Kältefettmarkierungen (cold resistant grease marking)

“+” 1942 – 1944 (mainly in 1943)
marked with a hellblaues Kreuz (light blue cross) “+”
introduced before November 1, 1942

“+” — kältebeständiges Fett (cold resistant grease) — “Instrumentenfett 1442” (“Instrument Grease 1442”) — marked with a hellblaues Kreuz (light blue cross) “+” on Dienstgläser (Service glasses) manufactured (or returned to a support facility for maintenance, repair, or regreasing) during 1942 and 1943.

According to Allgemeine Heeresmitteilungen (General Army Releases), the cold resistant grease “Instrumentenfett 1442” was introduced no later than August 6, 1942, and was certified to be fully operational for use on equipment to -40° Celsius (-40° Fahrenheit).

The earliest document referring to “Instrumentenfett 1442” — “+” — was the German Taschenbuch für den Winterkrieg (Manual for Winter Warfare), revised version dated November 1, 1942.

Evidently, soon after it was introduced, “Vakuumfett 1416” turned out to be unsatisfactory in actual field use. In the revised version of the Taschenbuch für den Winterkrieg (Manual for Winter Warfare), dated November 1, 1942, the “O” marking was not mentioned, and the “+” marking was introduced without explanation, with the statement that optical equipment marked with a “+” was perfectly serviceable to -40 degrees Celsius, and “in Zukunft wird das gesamte Beobachtungs und Vermessungsgerät des Heeres nur mit Instrumentenfett 1442 gefettet” (in the future, all observation and surveying instruments of the Army will be only lubricated with Instrument grease 1442″.

“Δ” Kältefettmarkierungen (cold resistant grease marking)

“Δ” 1943 – 1945 (mainly in 1944)
marked with a hellblaue Dreieck (light blue triangle) “Δ”
introduced late 1943 or early 1944

“Δ” — kältebeständiges Fett (cold resistant grease) — “Instrumentenfett 6009 (“Instrument Grease 6009”) — marked with a hellblaue Dreieck (light blue triangle “Δ”) on Dienstgläser (Service glasses) manufactured (or returned to a support facility for maintenance, repair, or regreasing) from 1943 to 1945.

Although no document exists referring to “Instrumentenfett 6009” — “Δ” — it is believed that this final cold resistant grease was introduced in late 1943 or early 1944, and was certified to be fully operational for use on equipment between -40° and -50° Celsius (-40° and -58° Fahrenheit).

Dienstglas "Rice"body covering Schwarz „Reis“ Körperbedeckung (black “rice” body covering)

Early in the Second World War, a black Rauhlack (rough lacquer) body covering called schwarz „Reis“ Körperbedeckung (black “rice” body covering) also became a common Dienstglas body finish.

This new Dienstglas body covering began to replace the black “Vulkanite” (synthetic, leather-like, early plastic) body covering material on the housings of German field glasses.

The particular consistency of this black „Reis“ (“rice”) Rauhlack (rough lacquer) body covering was achieved by mixing crushed rice or finely granulated cork meal with black lacquer paint.

This black „Reis“ (“rice”) Rauhlack (rough lacquer) body covering became the most common Dienstglas body covering as the war progressed through 1942 and 1943.

This is a list of production serial numbers, observed in collections and recorded from sources online, of 6×30 military service binoculars, manufactured by Carl Zeiss, Jena, (coded “rln”), for the armed forces of Germany from 1943 to 1945, during the Second World War.

Henryk Kolberg, 1924-1931
6×30 Production Serial Number Series

Henryk Kolberg
6×30, March 1925, 1896, Warsaw, Poland

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Henryk Kolberg
6×30, February 1926, 5898, Warsaw, Poland

These 6×30 military service binoculars are accompanied by the original brown leather carrying strap, and brown leather eye piece protector, or rain protection cover, or user cap.

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Henryk Kolberg
6×30, February 1927, 11205, Warsaw, Poland

These 6×30 military service binoculars are accompanied by the original brown leather carrying strap, and brown leather eye piece protector, or rain protection cover, or user cap, with attached brown leather button tab.

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Henryk Kolberg
6×30, July 1927, 13103, Warsaw, Poland

These 6×30 military service binoculars are accompanied by the original black leather carrying strap.

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Henryk Kolberg
6×30, November 1928, 19339, Warsaw, Poland

These 6×30 military service binoculars are accompanied by the original brown leather carrying strap, brown leather eye piece protector, or rain protection cover, or user cap, with attached brown leather button tab, and brown leather case with strap.

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