Cut sheet film holder

Discussion in 'Medium Format' started by iconoclastica, Jan 15, 2015.

  1. With my 3.5e came a plate adapter back with two cut sheet film holders. I now am trying to figure out how exactly they are to be used. It seems I've got on part more than shown in the manual. From back to fore these are:
    1. the back of the holder with the turning key
    2. (attached to 1) the carrier that comes forward when the key is turned
    3. a black plate the size of a film sheet that slides sideways in and out the carrier (as the sheets do)
    4. the black slide that covers the film
    What is the black slide (#3) for? The illustration in the manual just shows the carrier behind the film.
     
  2. A plate adapter is exactly what it says, and was designed to accept glass plates about 2.5mm thick. You can't fit 0.2mm thick cut film directly in a plate holder, so the metal sheath(s) is (are) used to hold cut film and pad out its thickness to approximate that of a glass plate.
    I had some experience using these terrible things many years ago on a quarter-plate camera. The focus can never be totally accurate because of the thickness of the lip on the sheath, and IMHO it's a waste of time trying to use such adapters. Just stick rollfilm in the camera and keep the plateholder on a display shelf as a novelty.
     
  3. Dustin McAmera

    Dustin McAmera Yorkshire, mostly on film.

    In your quarter-plate camera, you'd be unlikely ever to want to focus it for a plate again. Couldn't you shim the focus screen up (or back, if it's a rear screen) to make it be correct for sheet film?
     
  4. I agree with Rollei Joe in that the plate back is probably not worth the trouble. However I did spend quite a bit of time trying to learn to use it. The little black sheet should remain in the holder if you are using film. It is a spacer as Joe says. One of the problems I encountered using the plate back (and I own 4 or 5 of them) is the old velvet light shields are worn out and leak light. Another problem I encountered is remembering to turn the key and push the film up to the film gate before taking a photo.
    You don't mention it but there is another back made to fit in that has a ground glass for viewing the image through the taking lens. Originally not all kits had it and it was an accessory. However in my experience it is necessary to see what you are actually photographing and it is useful for checking the focus agreement between the taking lens and the viewing lens.
    The other useful thing about the plate adapter and film holder is that it allows you to use sheet film which is very flat and it pushes the film right up to the film gate so it gives you the maximum sharpness much like the optical glass back for the Rollei.
    Dennis
     
  5. Thanks for all this info! I don't see much advantage of sheet film over roll film here, except for one thing: experimentation with exposure and development times. The greatest problem, I guess, is not the camera or its back construction, but the availability of sheet film. Sofar, I have only seen it advertised in 25 ASA and not exactly cheap. Wouldn't it be possible to cut a 120 film in 8 sheets?
     
  6. Yes if you have a darkroom and a paper cutter. I use a chopper type cutter with tape to mark the sizes.
    From a 4x5 sheet you first cut a half inch off the long side so the film is 3.5X5. Then you chop it in half the other way so you are left with 2 sheets 2.5X3.5 which will fit in the holders. Or you can start with 5x7 film and and cut them in half both ways so you are left with 4 sheets 2.5x3.5 and no waste.
    If you buy Arista EDU Ultra film from Freestyle Photo it is pretty cheap. The problem is that you lose the code notch to help identify the emulsion side in the dark... So you need to make a working method that always keeps it one way or the other. I always keep emulsion side up when I am cutting and when in the box so I always know.
    The other thing to remember is that on that rectangle sheet of film you will only get a 6x6cm image. The way it works is that the image is all the way to one end of the rectangle so that you have the other end to use for handling the film.
     
  7. Dustin McAmera

    Dustin McAmera Yorkshire, mostly on film.

  8. I develop sheet film in trays with the shuffle method. For the 2.5x3.5 sheets I bought a glass butter dish to use as a developer tray. It is perfect size and keeps multiple sheets in a stack.
    Dennis
     
  9. "Couldn't you shim the focus screen up (or back, if it's a rear screen) to make it be correct for sheet film?"​
    I could indeed Pete, but the last time I used the 1/4 plate was about 45 years ago! Glass plates were still available back then (just). The camera's a Thornton-Pickard Junior Special reflex, which is now just for decoration, since the leather covering is turning brittle and in danger of disintegrating if the camera is actually handled.
    If I want to use cut film I have 2 5x4 technical cameras and a monorail to choose from. 5"x4" is much more readily obtainable and probably costs about the same per sheet as 1/4 plate or smaller.
    The suggestion to chop up rollfilm to fit the plate back isn't really that practical. Rollfilm isn't as thick as proper sheet film and would be difficult to use when cut up. There's no notch to tell you which side is the emulsion for a start.
     
  10. Working systematically and mitering the top right corner should keep track of the emulsion side. Crudely measured, sheet film of this size is about 200 um thick and 120 roll film 166 um. The stiffness of the latter is definitely less than of the film sheets. I expect that for experimenting it will suffice even if there will be a penalty for the film won't be flat. Trying to fit in developed film shows a lift of less than 1 mm off the back plane. I will just try it as soon as I can have a cutter adapted for blind operation.
    Pete, Thanks for the link. I develop in the paterson orbital. It may need a small adaptation to prevent the sheets floating all about.
     

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