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Recent content by LPT

  1. L

    Inside a vintage German "Hanseat" 8x30

    Those prism wedges are just like the ones in the 3 or 4 Hartmann Berninas I’ve had. My guess is that you are correct and the bino was made by Hartmann. Prism wedges like that, though, are not new. Goerz used them on some binoculars before WWI and the Belgian OIP’s had them during the 1950’s...
  2. L

    Hungarian military binoculars 6*30

    It almost surely was made by Magyar Optikai Müvek (Hungarian Optical Works) usually known as MOM which had a long history and made among other things respectable quality military optics as well as civilian model cameras: Once a world-famous factory in Budapest, now a hardly known company - The...
  3. L

    How many types of Porro prisms?

    As far as I know Zeiss, Ross and Barr & Stroud were the only manufacturers ever to cement a field lens to a Porro II prism in order to reduce the number of air/glass surfaces thereby increasing light transmission and reducing stray light. The Zeiss examples were mostly 7x50’s and marked H for...
  4. L

    How many types of Porro prisms?

    The real difference in Porro I and Porro II prism systems is the geometries of their light paths and not whether the prisms are cemented or not. Most but not all Porro II arrangements have cemented prisms but there are some examples of air spaced Porro II arrangements, and most but not all Porro...
  5. L

    Which binoculars fall over?

    Many of the early non-stereoscopic models with closely spaced objectives (Zeiss’ patent did not expire until 1908 and some companies continued to make them well after that) are not very stable when placed upright. This is why Huet and some of the other early French makers put little knobs...
  6. L

    When Were Dielectric Coatings for Roof Prism Binoculars Introduced?

    I didn’t know that that phase correction coating (“P“ coating) introduced by West German Zeiss in 1988 was a dielectric one. This is interesting, and I have learned something. So, yes it is clear that the first dielectric coating used in roof prism binoculars was the Zeiss P coating to correct...
  7. L

    When Were Dielectric Coatings for Roof Prism Binoculars Introduced?

    You are referencing anti-reflective coatings which are different than dielectric coatings. Anti-reflective coatings are to reduce light reflection and increase light transmission through air-glass optical surfaces. Dielectric coatings are to increase total internal reflection in prisms where...
  8. L

    When Were Dielectric Coatings for Roof Prism Binoculars Introduced?

    Does anybody know when the first dielectric coatings for roof prism binoculars were introduced and which manufacturer introduced them? I believe this has been discussed on this forum before but cannot find the link. I would think John A. would know.
  9. L

    Help Identifying Galilean Binoculars!

    I believe it’s American made circa 1920’s - ‘30’s. I think by a company in Chicago.
  10. L

    RN binoculars

    I can think of three military roof prism binoculars with graticules - the Canadian ELCAN 7X50, the U.S. Army M24 7x28 and the Zeiss Jena EDF 7x40, but there must be more. But all of those mentioned, however, are IF’s with conventional eyepiece adjustment focusing. I’m not aware of any Steiner...
  11. L

    Vintage Binoculars Help

    The binocular in question is a civilian model and was likely made circa 1919 - earlier 1920’s. Hensoldt did make some Porro I binoculars with widely spaced objectives between about 1900-1905 in violation of the Zeiss patent which would not expire until 1908 (see Seeger blue book pages 378-378)...
  12. L

    Did the US Navy Use Japanese Binoculars Prior to WWII?

    I‘ll bet the binocular was a center focus one too which was almost never the case for WW 2 period binoculars (unless it was a private purchase or one donated by civilians).
  13. L

    Did the US Navy Use Japanese Binoculars Prior to WWII?

    “Looking on IMDB someone said that the US used Japanese binoculars prior to the bombing Pearl Harbor. Is this true?” No, this is absolute nonsense. Prior to Pearl Harbor U.S. forces used mostly U.S. made Bausch & Lomb handheld binoculars together with a small number of naval Zeiss binoculars...
  14. L

    CZ 8x30

    Not all of the Oberkochen Zeiss were marked, “Made in West Germany”. I have some examples which are marked, “Made in Germany”. Why, I don’t know, but it may have been a political statement.
  15. L

    CZ 8x30

    They’re definitely authentic but West German Oberkochen Zeiss, not Zeiss Jena. The company split in 1945. Today’s Zeiss is the West German one. The East German Zeiss Jena ceased operations circa 1990.