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Thread: Questions-24 Inch Dagor

  1. #1

    Questions-24 Inch Dagor

    I HAVE A BRASS LENS MADE IN BERLIN BY C.P.GOERZ.MADE BETWEEN 1898 AND 1904,I THINK.IT DOES NOT HAVE A SERIAL NUMBER,NOR
    DOES IT HAVE THE F-STOP OR FOCAL LENGTH MARKED ON THE LENS.IT IS MARKED-DOUBLE ANASTIGMAT SERIES III NO.9-WHICH MAKES IT A F7.7 24 INCH DOGOR.QUESTION 1-THE STOPS ON THIS BARREL LENS ARE AS FOLLOWS-6-9-12-24-48-96-192-384-768.anyone know what this scale is?It does not seem to be american stops since there is no f-16.question2-since it is known to be a f7.7 can it be remarked with current f-stops.question 3-this lens needs to be taken apart and cleaned.that being the the case should i have it coated at that time-would those of you doing ulf black and white have any prefernce. question 4 anyone seen a dagor without a serial#? since this dagor is not marked as such it would seem to date it prior to 1904-any care to correct my thinking- please feel free thanks.

  2. #2

    Re: Questions-24 Inch Dagor

    Alan,

    the serial # should be on the barrel on the opposite side from the markings you posted. It would be most valuable in it's as-is condition. The aperture scale was used by Goerz, a member here, 'C.P. Goerz', posted the conversion quite some time ago, maybe you can find it with a search here.

    Hopefully it has it's flange with it

  3. #3

    Re: Questions-24 Inch Dagor

    Thanks Paul If this lens ever had a serial# I cannot tell it.Mayby its a 100 year hot lens? It does seen to be complete except for possibly a ring for the flange. I will have to give some thought to its value as is.

  4. #4
    the Docter is in Arne Croell's Avatar
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    Re: Questions-24 Inch Dagor

    1) That seems to be the Stolze aperture system, more information here (last post): http://www.largeformatphotography.in...ghlight=stolze
    2)Yes, see the post mentioned above.
    3)Recoating will be difficult and expensive. A Dagor consists of course of 2 cemented triplets. Given the age, the cement is Canada balsam. Since a hard coating needs somewhat higher temperatures, one would either risk misalignement or worse in the process (see http://www.focalpointlens.com/fp_intro.html), or the groups have to be "de-cemented", then coated, and recemented.

  5. #5

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    Re: Questions-24 Inch Dagor

    The only goerz lens I have seen without serial numbers (front AND rear cells) were those mounted in the Goertz XL shutter - where the outer rims are about flush with the shutter face. The numbers were stamped on this shutter face. So perhaps this was mounted in some kind of Goerz equipment like a episcope/horizontal enlarger/process camera?

    Coating is a very bad idea.

  6. #6

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    Re: Questions-24 Inch Dagor

    Coating of this old lens is always suspicious for an informed buyer, raising a natural question - how well was it done (i.e. the reassembly)?
    A good lens hood, possibly dedicated for the lens focal length and the film format in use will give a better result on pictures.

  7. #7

    Re: Questions-24 Inch Dagor

    Steven--------This lens matches exactly the cut view of a Goerv Double Anastigmat in a 1904 add.so I would say it is a camera lens.---------GPS-the proper lens shade is good advice.Two things about this lens annoy me,it has the faintest of cleaning marks on the front element-no affect on film.And on the back of the front lens There is a a1.5 mm spot of very fine dust-probably from the inside of the lens.The guys that made this lens loved machine tools It is screwed-glued and doubletaped.I would mot even consider trying to take the elements out of it.

  8. #8

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    Re: Questions-24 Inch Dagor

    Quote Originally Posted by alan-salsman View Post
    ...
    Two things about this lens annoy me,it has the faintest of cleaning marks on the front element-no affect on film.And on the back of the front lens There is a a1.5 mm spot of very fine dust-probably from the inside of the lens.The guys that made this lens loved machine tools It is screwed-glued and doubletaped.I would mot even consider trying to take the elements out of it.
    Well, unlike the faint cleaning mark, the 1.5mm dust particle is more than 100 years old! If that can console you...

  9. #9

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    Re: Questions-24 Inch Dagor

    Alan - Goerz used ordinary photographic lenses (with iris) on their "apparatuses" - in common with Zeiss and some English makers who found a growing market for their episcopes etc. The market for camera mounted 24" fairly wide angled lenses was quite limited.

  10. #10

    Re: Questions-24 Inch Dagor

    Steven-----Is the goertv XL shutter one of the old style shutters damped with a little air chamber like a volite?Never heard of it . The 24 inch is truly a wide angle. The 1904 specs. say at f35 it will sharply cover a plate 24x30 inches.

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