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R_J Joined: 03 Aug 2004 Posts: 137 |  Posted: Tue Sep 18, 2007 8:08 pm Post subject: Buschman 1/4 plate camera: looking for information
Back in London, my local camera store seems to be shelving everything.
Having no more 1/4 plate film holders, I've 0000000found a Buschman 1/4 plate camera with a Goerz Dogmar 150mm f4.5 lens in perfect operational condition. I've searched the archives here and little information seems to crop up.
From what little I know, this is a box design camera with a rear focal plane shutter. There are 3 slit widths which correspond with shutter speeds of 1/15th - 1/1000th of a second using the shutter dial permutation. The design strikes me as if it must have been made after the 1920's, and perhaps before the war.
What amazes me about this Buschman is the single-lens reflex design: there is a viewfinder hood with a mirror lock up design, in addition to a rear ground glass design. Best of all, the camera comes with a mating 120 roll film Rollex back.
Although this might seem shocking, I wonder if anyone can advise on whether the rear focal plane shutter can be removed as a unit from the camera and used as a focal plane shutter for front-mounted lenses on a larger format camera.
I gather the Dogmar lens is a simple Dialyte construction of low-contrast.
Kind regards,
RJ |
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45PSS Joined: 28 Sep 2001 Posts: 4081 |  Posted: Wed Sep 19, 2007 6:11 am
From the Vade Mecum
Dogmar
Dogmar A new dialyt series was announced in Photography 26/05/1914, working at f4.5 in the shorter foci.
Since it was very late prewar, most examples will be postwar. Adverts. stressed it was a very highly corrected
lens, but the major sales feature was that it was separable, the front cell giving 2x focus, and the rear one 1.5x
focus. It was said to be free from ghosting, and the f4.5 was initially made in up to wholeplate size, the longer
sizes being in f5.5. It covers 55° or 54° at full aperture, and 60° at smaller apertures. It was suggested to use
21cm for 13x18cm plate. The f5.5 covered a slightly larger angle (54-60°) and a slower version at f6.3 covered
a bit more again (60-65°). However it was not primarily sold for its angle of cover, and the slower version was
short lived, being replaced by the Tenastigmats, etc.
The designer was W. Zschokke, and it was covered under Patent 258,494 and sold from 1914. It is sharper
than Celor, and shows better edge detail than the Q15 type designs. [Zschokke then left Goerz after the
association as Zeiss Ikon, and designed rather similar lenses for Kern, possible perhaps due to the take over
by Zeiss Ikon and the absence of this lens type in the Zeiss lists.]
Dogmar f4.5 60, 75mm for 2.375x2in, 90mm for 2.75x2.375in, 100mm for 2.5x3.5in,
125mm for 4.25x3.25in, 125mm for 4.25x3.25in, 135mm for 4.25x3.25in, 150mm for 4.75x3.5in, 165mm for
5x4in, 180mm for 6x4in, 195mm for 6.5x4.75in, 210mm for 7x5in, 240, 270, 300mm. Use 165mm for 5x4.,
14in for 10x8. (Goe005,009. Q26 type). Separable, 3 focus. It covers 55° and there is no suggestion of
improved cover when closed down. The other foci of the single cells were not detailed in adverts. |
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Dan Fromm Joined: 14 May 2001 Posts: 2165 |  Posted: Sat Sep 22, 2007 8:13 pm
R_J, do you have a saw?
Cheers,
Dan |
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R_J Joined: 03 Aug 2004 Posts: 137 |  Posted: Tue Sep 25, 2007 3:57 pm
Looking closer at the design of the focal plane shutter from the rear, I see that the ribbing on the exterior is merely cosmetic and not designed as a bolt/separable unit from the main chassis of the Buschmann.
Thanks 45PS - I've seen a similar description. Perhaps the lens might be more useful on a Graflex Century which has more movements than on the 1/4 plate. Alas...no focal plane shutter on the Century. |
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second-belated Joined: 30 Sep 2007 Posts: 7 |  Posted: Sun Sep 30, 2007 8:36 pm
RJ,
I have a Dagor in a gutted barrel.
No aperture iris, but wide open it still performed fairly well considering its rear element scratches.
Worth a few shots. I personally love Goerz lenses and am actively seeking more Dagors and Dogmars in my price range  |
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R_J Joined: 03 Aug 2004 Posts: 137 |  Posted: Sun Oct 07, 2007 11:23 pm
Hi there,
thanks for your thoughts.
I'm sure the Dogmar is worthwhile trying: time limitation aside, perhaps it is the 1/4 plate format which causes too much inertia for me to pursue these efforts.
It seems overly brutal to take a saw to the Buschman just for its focal plane shutter. Perhaps it is worthwhile for someone else to try out instead.
Kind regards,
RJ |
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Dan Fromm Joined: 14 May 2001 Posts: 2165 |  Posted: Mon Oct 08, 2007 3:28 pm
RJ, I suggested the saw because the shutter assembly should be integral with the rear of the camera body, which I believe is a wooden box. If you want to use the shutter without cutting the box, you'll have to make a box yourself ...
Cheers,
Dan |
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R_J Joined: 03 Aug 2004 Posts: 137 |  Posted: Mon Oct 08, 2007 6:39 pm
Hi Dan,
Thanks - I realised on inspecting the camera that the shutter wasn't easily separated.
Unfortunately the focal plane shutter is the most appealing part of the Buschman for me, having neither penchant for 1/4 plate and Dogmars, nor a love of the rather oblique box design.
Maybe the saw should be the next move.
Kind regards,
RJ |
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R_J Joined: 03 Aug 2004 Posts: 137 |  Posted: Mon Mar 10, 2008 8:56 pm
| Quote: | Dogmar A new dialyt series was announced in Photography 26/05/1914, working at f4.5 in the shorter foci.
Since it was very late prewar, most examples will be postwar. Adverts. stressed it was a very highly corrected
lens, but the major sales feature was that it was separable, the front cell giving 2x focus, and the rear one 1.5x
focus. It was said to be free from ghosting, and the f4.5 was initially made in up to wholeplate size, the longer
sizes being in f5.5. |
Having re-read this note, I thought it too incredible to be true - that the 150mm f4.5 Dogmar, could actually cover whole plate. It seems highly unusual that a lens, mounted on a 1/4 plate camera should have such an excessive image covering circle.
I remounted the 150mm f4.5 from the Buschman plate camera onto a Sanderson whole plate camera, and behold: it does it indeed cover whole plate format at infinity with full aperture. |
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