Flim Holder Light Leaks Revisited

Discussion in 'Large Format Cameras and Accessories' started by photomc, Apr 4, 2005.

  1. photomc

    photomc Member

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    Ok, so I have some older holders (Kodak) for the 5x7 and noticed that I seem to have what I think are light leaks with some. So, placed some paper in them to test for light leaks, placed the holders, with dark slides in and let them sit in some sun on the patio yesterday. Then last night processed the paper and sure enough some of the holders to have a light leak.

    Great, now I know which ones leak, but after searching the threads here did not really find anything on how to fix them. So the question now is what do I do, hate to toss them, they are in good shape as far as I can see, but if not light tight - well. Anyone have sound advice on how to repair or can point me to a link?

    Thanks,
     
  2. bobfowler

    bobfowler Subscriber

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    A lot depends on where it's leaking... Most leaks seem to be from the flap (tape problems) or the light trap where the darkslide goes in (pain in the butt to fix).
     
  3. photomc

    photomc Member

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    Thanks Bob, just had a nice discussion in the chat room about this as well, Dave and Allen gave me some good ideas to check.
     
  4. Jeremy

    Jeremy Member

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    I have one giving me trouble, can you post what works and doesn't work for you?
     
  5. Donald Miller

    Donald Miller Member

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    The places that are prone to leak on the older Kodak holders are either at the flap end or at the light trap. The flap end interlock (not the flap itself) at times will separate and may need to be reglued. The tape at the flap can degenerate...B&H had the replacement tape for sale at one time...I imagine that they still do. In lieu of that 3M photographic (black) tape will work. The light trap plate is removable with four small screws. The problem in this area can either be degradation of the felt overlay at the trap. This can be replaced with a comparable material available at a fabric store. Underlying the felt overlay is a spring metal. This is beryllium copper. Beryllium copper is available from Small Parts. Be careful if you grind this metal... it is nasty stuff especially to one's respiratory tract.

    Beyond that the only other potential for a light leak in the holder itself would be a crack in the darkslide...that would be apparent.

    Most of my leaks have been at the flap end...and amounted to separation at the flap interlock...and not the tape itself.
     
  6. photomc

    photomc Member

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    Great information Donald, Thanks!! Will look for the tape and post a link if I find it.

    Jeremy, Donalds post pretty much covers most of what we discussed..one thing that came up is the tape on the flap can develop pin-holes, of course the other was to be sure and check the back itself and make sure it is not causing some of the light leak. Since I was just checking the holders they never saw the camera, but will reload with more paper negatives and check the back - insert film holder with paper neg in the camera back - pull the dark slide - replace darkslide - remove film holder (I know you know this, it is really to re-enforce the steps for myself)
     
  7. Campy

    Campy Member

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    Perhaps I'm misunderstanding a couple of the messages here but some seem to be saying that bad tape may be causing light leaks. The tape on a film holder serves no "light prevention" function, it's the light trap that keeps light from coming in at the base of the holder. The tape is there only to serve as a hinge so that you can get film in and out of the holder. If tape is being replaced you don't need "replacement tape" or any other special kind of tape. You could use clear Scotch tape if you wanted to, it would have no effect on light getting into the holder.
     
  8. Donald Miller

    Donald Miller Member

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    Thanks for amplifying on this...you are absolutely correct.
     
  9. Murray@uptowngallery

    Murray@uptowngallery Member

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    I thank you also. I wasted money special-ordering Kalt black phototape, thinkin it would be black crepe type but was actually white under the semi-glossy black surface...full of pinholes (4 layers to block a flashlight beam) and leaves a horribly sticky residue if removed.

    I assumed the eroding black crepe hinge tape on my old untested filmholders was in need of repair...no telling how much time I could have wasted taping and retaping the wrong place!

    The bad side of this was now it seems like it'll be harder to fix light leaks, if th eeasy job of retaping the hinge doesn't do it :O)

    Murray
     
  10. David

    David Member

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    And speaking of dark slides that leak light, does anyone have a suggestion on repairing cracks in the phenolic resin or plastic slides - or conversely, where to get replacements for 8x10 Fidelity holders? Thanks.
     
  11. Donald Miller

    Donald Miller Member

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    I have repaired a number of them by pressing the cracks into alignment and applying quick set epoxy... Replacement slides were sold at B&H at one time...don't know if they still have them.