building a monster enlarger

Discussion in 'Darkroom Equipment' started by Rick A, Jul 16, 2009.

  1. Rick A

    Rick A Subscriber

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    Okay, I've done something bordering crazy. My neighbor gave me an 18x24 vertical copy camera, and I've decided that it would make a great enlarger. The bellows are in good shape, and it has a Goerz lens of unknown focal length. Well I stripped it down to bare frame(still weighs over 150lbs) and built a light mixing chamber out of 19mm plywood. I moved the fluoresent light box(12 18" tubes) to the top of the chamber, so far so good! I placed the vacuum negative easel to where the light box/stage came from, this is now a vac. easel. My only concern, is how to make the neg. carrier. I think I am going to build a drawer for the bottom of the light chamber, and use different size masks for my negs(sounds simple).
    How far above my negs should I have my diffusion glass? I have 2 large pieces of AN glass to sandwich the negs, how much , if any, effect will this have on print quality?
    If I wasn't such a caveman, I could figure out how to upload pix of this monstrosity to let you see what I'm doing. BTW -- I only have analog cams, and I cant figure out how to use my stupid scanner.
    Well, I guess I'll get it fiured out, and let you know if it works.
    Rick
     
  2. Rick Levine

    Rick Levine Member

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    The first thing I'd do was replace the fluorescent light source with an incandescent one. My Beseler uses EVW lamps which create quite a bit of output.
     
  3. richard ide

    richard ide Member

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    I used fluorescent tubes in three enlargers I built. They were all horizontal and I was making big (up to 72" x 192") enlargements. I made ortho masks to compensate for light fall off. For small enlargements, you may need a shutter to take in to account the start up time of the lamps. I would recommend one AN glass on top of your negative. Your camera came with either a vacuum back or a glass plate to place the film on. There should be a lip on the top to support a sheet of clear glass. I used vacuum to hold my negatives flat on the glass.
     
  4. AgX

    AgX Member

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    Rick,

    18x24 cm or inch?
     
  5. Rick A

    Rick A Subscriber

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    INCHES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
     
  6. Rick A

    Rick A Subscriber

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    I'm going to have to sandwich my negs between glass. The vacuum back is being used for my paper easel. This is a vertical rig(I only wish it were horizontal) so I am limited in enlarging size, unless I lay it down. alas ,I dont have the room for that. The lower copy stage is crank operated to raise and lower, and that is where I've moved the vac back to make the easel.
    Thanks for recommending a shutter, as I have been pondering this for awhile. Would a swing away RED filter suffice? I have already installed one on the lensboard. The lamps are controlled by an onboard timer, so I figured I'd just swing the filter over the lens at shut down.
    Thanks for the input.
    Rick
     
  7. Nicholas Lindan

    Nicholas Lindan Advertiser Advertiser

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    Graphic arts process cameras can be used unmodified as enlargers. Put the negative on the backlit copy board or other diffuse light source like an old cold light head. The paper goes on the vacuum back.

    There is no difference in which side of the camera the paper goes: the lens on the camera is symmetrical; the reproduction ratio is symmetrical - usually 1:3 to 3:1; the size of the vacuum back is also the size of the copy board;

    The problem with an unreversed camera is dodging and burning - you have to hold the tools over the negative. For that you need large negatives like 8x10.

    Because the enlarging ratio is pretty limited you may want to use a shorter lens. If the camera is not reversed then you may have to raise the copy board unless the camera has extra lens board travel and extra bellows extension. If the camera is reversed then you may have to make a recessed lens board.
     
  8. Rick A

    Rick A Subscriber

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    Then I was correct in reversing my camera.