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Re: [woodandbrass] Antique brass CZJ 240mm Anastigmat-Weitwinkel lens!

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  • Milan Zahorcak
    Part 3 Oh, good grief - Figure 66 on page 55.
    Message 1 of 17 , Aug 16, 2012
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      Part 3

      Oh, good grief - Figure 66 on page 55.


      On 8/15/2012 9:46 PM, Milan Zahorcak wrote:
       

    • John Rushton
      Hi All, And I have No. 44, which is a different lens, being a Carl Zeiss Jena 310mm Triplet Apochromat, as shown below.
      Message 2 of 17 , Aug 17, 2012
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        Hi All,

         

        And I have No. 44, which is a different lens, being  a Carl Zeiss Jena 310mm Triplet Apochromat, as shown below.

         

        http://tinyurl.com/chhm6kb

         

        The only information that I have on this lens is shown in one of the images at the above link.

         

        Best Wishes,

        John

         

         

         

         

         

         

        From: woodandbrass@yahoogroups.com [mailto:woodandbrass@yahoogroups.com] On Behalf Of dcolucci@...
        Sent: 15 August 2012 12:23
        To: woodandbrass@yahoogroups.com
        Subject: Re: [woodandbrass] Antique brass CZJ 240mm Anastigmat-Weitwinkel lens!

         

         

        David,

         

        While you have # 39, here is # 40

         

         

         

        Dan

         

         

         

         

        In a message dated 8/15/2012 5:33:35 A.M. Eastern Daylight Time, ole@... writes:

         

        I don't have my documentation here at work, but a bit of multilingual
        googling brought up some results.

        http://depatisnet.dpma.de/DepatisNet/depatisnet?action=pdf&docid=DE000000056109A

        That's the original Anastigmat patent, Kaiserliche Patentenamt
        Patentschrift No 56109.

        Figure 1 looks very much like your lens. As far as I know this
        construction was not put in production, or if it were then there must
        have been a very small number made.

        Ole Tjugen


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      • Stephen Shohet
        Thank you, Richard for the PDF with patent pictures! Clearly very different from any bigdistant bizarre variation on a Goerz-type double meniscus. Steve
        Message 3 of 17 , Aug 17, 2012
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          Thank you, Richard for the PDF with patent pictures!  Clearly very different from any bigdistant bizarre variation on a Goerz-type double meniscus.    Steve 
        • Richard Knoppow
          ... From: Stephen Shohet To: Sent: Friday, August 17, 2012 4:46 PM Subject: [woodandbrass] Re: Antique
          Message 4 of 17 , Aug 19, 2012
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            ----- Original Message -----
            From: "Stephen Shohet" <sbshohet@...>
            To: <woodandbrass@yahoogroups.com>
            Sent: Friday, August 17, 2012 4:46 PM
            Subject: [woodandbrass] Re: Antique brass CZJ 240mm
            Anastigmat-Weitwinkel lens!


            > Thank you, Richard for the PDF with patent pictures!
            > Clearly very
            > different from any bigdistant bizarre variation on a
            > Goerz-type double
            > meniscus. Steve
            >
            The story is that Von Hoegh approached Zeiss with the
            design for what became the Dagor and was turned away. He
            then went to Goerz who accepted the design and made the lens
            but swindled von Hoegh out of his royalties.
            The reason Zeiss declined the design was that Paul
            Rudolph was already working on a similar lens. von Hoegh
            shows two versions of the Dagor in his patent differing in
            the order of powers of the cemented elements. The version
            that was produced by Goerz has the positive elements on the
            outside, the opposite arrangement was used by Zeiss for one
            version of the Protar and by Watson for the Holostigmat.
            This is sometimes called a "reversed Dagor" Voigtlander
            used yet another arrangement for the Kollinear which has a
            positive element on the outside, a second positive element
            in the center, and a negative element facing the stop.
            Schneider used a reversed Dagor for the well known Angulon.
            Because the reversed Dagor is somewhat longer than the
            normal Dagor the Angulon has oversize end elements to avoid
            vignetting. The Wide Angle Dagor has equal coverage without
            the extra large elements. Note that while the Angulon has
            an enormous circle of illumination its actual coverage for a
            reasonably sharp image is only about 95 degrees about the
            same as for the W.A.Dagor. To get this coverage both lenses
            must be stopped down to about f/45.
            In fact the f/18 Zeiss Protar must also work at about
            f/45 for its maximum coverage, again about 95 degrees. The
            Schneider Angulon is slightly unsymmetrical. The purpose is
            to improve the correction for distant objects.
            I have what seems to be a prototype Angulon, its an
            awful lens. According to a friend who is a lens designer the
            original patent specifications indicate this. Some error was
            made in the design. Since a lot of Angulons were built and
            evidently had satisfactory performance it must have been
            redesigned rather early in its production. Mine has very
            serious color fringing which lenses of this type should be
            pretty much free of.


            --
            Richard Knoppow
            Los Angeles
            WB6KBL
            dickburk@...
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