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Thread: "Easy" single film holders for 30x40cm Reisekameras

  1. #1

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    "Easy" single film holders for 30x40cm Reisekameras

    As I only had one double book holder for my 30x40cm (slightly less than 12x16") I decided to attempt to make some additional holders.
    I am little coy about this as the present finish of the completed holder is not quite to finish of the camera, but as I understand there are at least 2 people out there with a splendid similar camera but without any sort of holder, I decided now was the time!

    First of all, no-one is up to the job of making replica book holders for themselves - and the cost of ordered one from someone who has the mahogany and tooling would be quite prohibitive. Auction sites very very rarely have them.

    My solution is to make single sided film holders with about the same thickness of the ground glass holder. Precise thickness is not important as it is the locking system on the front face side of the holder which determines the distance to the film. Extra thickness will just stick out behind the camera. This means that those without a genuine plate holder can use the ground glass holder as a guide for wood dimensions and the "catching" brass strip.

    My solution was to use thin strips of "wood" from a wood slated blind (see 1st photo) with alternative overlapping at the corners. This looks like real wood but appears to be some sort of fibre product and a lacquer finish. The important thing is that these have the right dimension for building up layers which provide distance to film plane, "cavity" for dark slide and flange for pressing the sheath into position (or for back loading of film through a rear door). Reducing the thicknesses of the slats, to locate the focussing distance, is quite easy.


    Quite a lot of lengths are needed and squaring up of precise sawn lengths takes time. The slats I have worked with, don't like glue much, so sandpapering was necessary. Instead of cutting each slat individually before glueing and clamping, I used the full width slats and then trimed the "sticking out" sections when the frames was rigid. The dark slide was stolen from my wife and is the back plate of a "time and motion studies" loose paper holder.

    Cutting the 4 brass corner strips is not too difficult. I used a thickness that was the same as the slat thickness to make things easy. I added a few extra screws to increase my confidence about the slats not giving light leaks. The whole thing was stabilised with a good quality plywood back. The next one will be made with some kind of door and a light seal for back compression loading of sheet film without a sheath.

    Rough diagrams and some specific measurements tomorrow.
    Attached Thumbnails Attached Thumbnails 30x40slatholders 001.jpg   30x40slatholders 004.jpg   30x40slatholders 002.jpg   30x40slatholders 003.jpg  

  2. #2

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    Re: "Easy" single film holders for 30x40cm Reisekameras

    The focussing depth of ground glass surface from the fitting flange is 9mm on my camera and the edge/bottom width of the mahogany framing of the darks slide is 25mm.
    The wooden slats from an old blind have just under 3mm thickness and a width of exactly 25mm! This means that I can use a "build-up" of 3 slats to get down to the film plane. It is possible to adjust the position of the ground glass or apply thin paper strips to increase the distance of the film plane.
    I have shown the position of the slats for the similar 2 sides and end. The second one is offset to allow a channel for the darkslide and the last one is again offset to allow for the chosen size (regular 30x40cm or Imperial 12x16"). There is a difference of about 25mm at both sides for these two formats. The top piece has just 2 slats and the bottom is also offset for the loose film or film sheath.
    I have shown the backplate as one piece, But a trapdoor is possible for back loading of film, but in this case I would suggest corner metal reinforcements. There isn't much room for the traditional rebate light trap, so I would suggest an overlapping type with velvet light seals.
    The darkslide I found was slightly oversize (more than 3mm) so this was reduced at the edges and bottom.

    The light seal around the plate holder is accomplished by permanent velvet seals on the camera. There has to be a thin material light seal on top of the two layer top piece,
    Attached Thumbnails Attached Thumbnails slatholder.jpg  

  3. #3

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    Re: "Easy" single film holders for 30x40cm Reisekameras

    I forgot to show the top wood piece across the entry for the dark slide. Without this, there will be a massive light leak. This was removed so that I could install the felt seals. Note this section is held in place by the two top corner strips and short brass screws.

    I will be making another one this summer - so perhaps photos of the stages will help comprehension!

  4. #4
    Guilherme Maranhão coisasdavida's Avatar
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    Re: "Easy" single film holders for 30x40cm Reisekameras

    Steven, thanks a lot for this idea. I was looking at the holders in Allan Greene's book Primitive Photography, but they have a complex way of holding the film in place. Your approach led me to what I think will be a nice solution for my future 16x20 camera.

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