Author Topic: DMR "Congrès" view camera  (Read 834 times)

Thomas Stellwag

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Re: DMR "Congrès" view camera
« Reply #15 on: August 29, 2020, 15:09:07 »
thanks a lot for sharing this with us
it looks very good and I wish you a lot of fun in using it
Thomas Stellwag

Airy

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Re: DMR "Congrès" view camera
« Reply #16 on: August 29, 2020, 16:51:59 »
The "dream" would be to shoot my ancestor's postcards again. The next big step would be to test photo paper. Since the shutter, though working, is in a dubious condition, I'd use a lens cap and a long pause. Normal photo paper should be OK; direct positive paper (Harman or derivated) is available too, but might be too contrasty; otherwise its sensitivity should be just right (ISO 1 to 3...). Some users recommend developing it with a mix of instant coffee, soda, and C vitamin: finally, chemicals that you can pour into the sink without remorse.

I'd also need a tripod (the original might not have been preserved, and browsing through my grandparents' attic will take time). Maybe my current tripod + an adapter for the bottom plate thread will do: the view camera is not very heavy. Used ones are available on eBay, too.

The ground glass is missing, but fabricating a replacement is no big deal.
I might also use the preserved chassis (two of them, double-sided) to hold the photo paper, but their sophisticated blinds (wood on fabric) are hard to manoeuver, still need to work on them.

For my darkroom, my son will lend me one of his bicycle rear lights :) wonderful technology.
Airy Magnien

Erik Lund

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Re: DMR "Congrès" view camera
« Reply #17 on: August 30, 2020, 02:40:40 »
Nice to see the journey is off to a great start!
there seems to be only a free references to the lens maker, I think there is one on eBay but I have no knolage if it fits your DMR.


Very nice living room image and using the Df to capture it seems like a great connection indeed ;)
Erik Lund

Airy

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Re: DMR "Congrès" view camera
« Reply #18 on: August 30, 2020, 09:15:44 »
I'm done checking the fundamental mechanisms. The "Congrès" has a pyramid-shaped bellow with the smaller front part mounted on a ring, so it is possible to rotate the rear plate and the bellow by 90° and switch between "portrait" (default) and "landscape" orientation.

(hey, what about rotating sensors? on mirrorless cameras of course. Better: square ones)

The bottom plate can slide forward, under the front plate, and allows to lock the unfolded camera in its unfolded state.

I'm still investigating the shutter (single curtain):

- it locks well in the "open" position, allowing to use the matte screen;
- I did not succeed, so far, in locking it into the "armed" position; some old bakelite stuff remains, maybe there is a broken part missing;
- the speed setting works, but I did not yet find the trick to release the spring (reduce the speed).

I found a thread (in French) about restoration of such sort of shutters, so there are elements available for my better understanding.
Airy Magnien

PeterN

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Re: DMR "Congrès" view camera
« Reply #19 on: August 30, 2020, 11:10:23 »
Wow. That must give you a very special and proud feeling, Airy.
Thank you for sharing the story and please keep sharing examples!
Peter

Airy

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Re: DMR "Congrès" view camera
« Reply #20 on: August 30, 2020, 21:55:07 »
The sliding mechanism that moves the back plate back and forth. The plate with the spirit level, on the bottom of the 1st shot, is the one in which the rear plate is locked. It is turned upside down on the second shot, revealing the two racks. Note :
1) the spirit evaporated, gosh
2) the missing blocking mechanism and button. Too bad. With the smaller lens, the bellow extension is moderate, and the back plate stays in place even without that help.
Airy Magnien

Airy

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Re: DMR "Congrès" view camera
« Reply #21 on: August 30, 2020, 22:00:32 »
This is the frame waiting for a replacement matte screen. It can be moved aside to allow the insertion of photoplate chassis.
Airy Magnien

Airy

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Re: DMR "Congrès" view camera
« Reply #22 on: August 30, 2020, 22:02:46 »
One bottom plate can slide to lock the bottom and front plates at 90°; here, it is in "unlocked" position (moved to the right).
Airy Magnien

Airy

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Re: DMR "Congrès" view camera
« Reply #23 on: August 30, 2020, 22:07:13 »
The bellow and rear plate can rotate by 90° WRT optical axis, enabling "portrait" and "landscape" orientation without moving the camera.

Of course, in the landscape position, the frame lies on its long side and is too low, so...
Airy Magnien

Airy

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Re: DMR "Congrès" view camera
« Reply #24 on: August 30, 2020, 22:11:31 »
... this version of the DMR "Congrès" has an additional sliding plate to offset the whole front mount by 3 cm (moving the index from "centre hauteur" to "centre travers"), restoring axis coincidence. Vertical shift can be applied as before (max +/-3cm). The last pic shows the front plate "offset" drop (3cm) with no further vertical shift applied (see the right index).
Airy Magnien

Erik Lund

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Re: DMR "Congrès" view camera
« Reply #25 on: August 30, 2020, 23:17:50 »
Very high workmanship and attention to detail! Wow
And still in very good condition, quite impressive  ;D
Erik Lund

Jack Dahlgren

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Re: DMR "Congrès" view camera
« Reply #26 on: August 31, 2020, 18:57:00 »
... this version of the DMR "Congrès" has an additional sliding plate to offset the whole front mount by 3 cm (moving the index from "centre hauteur" to "centre travers"), restoring axis coincidence. Vertical shift can be applied as before (max +/-3cm). The last pic shows the front plate "offset" drop (3cm) with no further vertical shift applied (see the right index).

Interesting that the shutter is at the lens board. I have a couple of Graflex cameras with a similar curtain shutter in the rear standard, but having it up front where it can be smaller and lighter is a good idea. I used to use photo paper with the 4x5 when I was a poor student. Would develop the "negative" then contact print (emulsion to emulsion) onto paper for a positive (but reversed) print. Contrast was substantially higher than film, but could be used to good effect. Now with scanners, maybe you can achieve a more normal contrast range. No need for a working shutter with paper negatives. Just carry a lens cap or opaque cloth and a timer. I think it was in the range of several seconds in daylight. It is possible you could use variable contrast paper, but when I was doing this the VC paper had printing on the back so would not work for contact printing.

golunvolo

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Re: DMR "Congrès" view camera
« Reply #27 on: August 31, 2020, 22:06:23 »
Airy, ole! What a project.

Peter

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Re: DMR "Congrès" view camera
« Reply #28 on: October 09, 2020, 18:24:08 »
I can smell that Antique wood through my monitor...
What a great looking camera..