Gandolfi, and Light Leaks

Discussion in 'Large Format Cameras and Accessories' started by KenM, Sep 22, 2003.

  1. KenM

    KenM Member

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    I purchased a used Gandofi Variant Level 3 a few months back, right before I began construction on my new darkroom. I ran some quick tests, found everything to be satisfactory, and ended up selling my Toyo 45AII.

    A few weeks ago, after I had finished the darkroom, I started going out more with the camera. However, I found that I was getting fogged negatives. I initially though it was the Grafmatic backs, but after further testing, and careful inspection of the camera, I found that it was letting an unsettling amount of light in (well, any light not coming in through the lens would be unsettling!).

    There were three light leaks:

    1. Around the lens opening in the front standard, due to poor fitting lens boards. One of my lens boards was fine; the other three were way too loose. This leak was fixed by putting a ring of weather stripping around the inside of the opening, painting the opening black (it was finished wood before), and using black tape on the inside of the opening to make sure that no light would leak underneath the weather stripping. Leak covered.

    2. My camera has a revolving back (Calumet/Cambo?). When a light is shone from the inside of the camera out at a very particular angle (with a grafmatic loaded), you can see light on the outside of the camera. However, going the other direction does not show any light at all, at least that I can see.

    3. After further investigation of the back, it appears that Grafmatics don't work particularly well with this camera back - the springs are stretched too far to hold the back snugly in place. I thought about using the backs with just the clips (remove the glass), but I'm not confident that the clips would hold the back securely enough. After further investigation, it appears that #2 may be caused the Grafmatic's as well, due to the stress put on the revolving back.

    As I test, I put all my 2-sheet film holders through a strenuous test outside in the bright sunshine, with no protection for the back. Expose a negative, rotate the back, and the camera in the sunshine. Developed all the negs - no fogging.

    So, I'm back to my cut sheet film holders. I can only carry 24 sheets of film as opposed to 36, but it's still pretty tough to run through 24 sheets in a single day.

    After that long narrative, has anyone else has problems with rotating backs? How about light leaks in general - had problems finding a leak?

    It took me about 3 hours Friday night, and a few hours Sunday to diagnose and fix all these problems. I know, however, can rest assured that I have a light-tight camera.

    I hope :-D
     
  2. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

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    I'm not sure about the Gandolfi, but I use Grafmatics on my Technika with just the clips and the groundglass removed, and they work fine. They were designed to work that way, mainly for press photographers focusing by rangefinder who didn't need the extra weight of a groundglass back.
     
  3. KenM

    KenM Member

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    Well, the camera back is, I believe, a Calumet or Cambo rotating back, so it's a *standard* back (as standard as you can get, I would guess). The clips, however, do not fit into the groove on neither the Grafmatic backs, or the standard cut sheet holders. I had the same problem on my Toyo.

    Do the clips on your back fit into the grooves?
     
  4. BobF

    BobF Member

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    I use graphmatics almost exclusively for cut film on a Tech IV under the spring back. I rarely use the graphlocs and unless I get over eager in working the film drawer I do not get light leaks.

    In the past I did get light leaks with graphmatics as I found I was pulling back when operating the film changing drawer. If you use the graphlocs like David does you won't have this problem.
     
  5. KenM

    KenM Member

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    Sorry, nope.

    I can take a flashlight,and shine it onto the back from the lens standard (without the lens, of course) and I can see light flashes through a small space at the corner of the grafmatic - it just doesn't seat flat.

    The holder seems to be flat, it just doesn't sit 'deep' enough.

    A two-sheet holder does not have this problem - I just finished running a few more tests, and no fogging at all. I rotated the camera through all the motions, making sure sunlight hit all parts of the camera.

    Barnbaum uses Gramatics with a Tech IV as well, and he doesn't get light leaks either....

    Me? I'll stick with cut sheet holders for now.
     
  6. BobF

    BobF Member

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    That's odd as when I look at a Lisco vs. Graphmatic it appears to me that a Lisco would be more likely to leak at the corner. Oh well, graphmatics are certainly not necessary but it would drive me crazy trying to figure out why.

    I would probably end up destroying both camera and graphmatic in a possibly futile attempt to fix. A personal failing :surprised:ops:
     
  7. Jorge

    Jorge Inactive

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    Gandolfi is pretty good at answering e mails, why not drop them a line?
     
  8. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

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    Yes, the Graflok slides fit the grooves on a Grafmatic properly on my Tech V.
     
  9. KenM

    KenM Member

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    By jove, I think I found the problem.

    Check out this link:

    http://www.apug.org/site/main/album_page.php?pic_id=672

    You're looking at the bottom left of the camera back, removed from the camera.

    See the tab on the left? That tab prevents the grafmatic from sliding in all the way. The ridge on the grafmatic therefore doesn't slip into the groove on teh camera back, making a light-tight seal. If you do push the back down far enough to seat the notch and groove, the bottom left of the back is raised away from the camera back, again preventing a light tight seal.

    My question is this: what the heck is that hole for? It's threaded...

    I'm tempted to grind the sucker off.

    Opinions?
     
  10. BobF

    BobF Member

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    Since that's the kind of thing I would do I'll give you the benifit of my hard won and often painful experience. DON'T DO IT!!!

    Really why not try Jorge's idea first.
     
  11. KenM

    KenM Member

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    Well, I've sent a note to Gandolfi, asking them what the hole is for. It must be for an accessory, for for which one? Regardless, it interferes with the grafmatic, so as far as I'm concerned, it's toast. It's quite simple to remove, since most of the aluminum is already gone, due to the hole.

    My bet is that the back was designed without taking into account the thickness of the grafmatic, and it's need to seat fully into the recessed notch. After all, grafmatics haven't been made for years. Perhaps the back was designed to work with standard thickness film holders.

    Regardless, thanks for the warning! :wink:
     
  12. KenM

    KenM Member

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    Just got off the phone with Calumet - Jose said that the hole was for a Prontor press shutter cable, used to close the shutter.

    Out comes the file when I get home. :twisted:
     
  13. Eric Rose

    Eric Rose Subscriber

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    Weird, as my Cambo back works fine with grafmatics either using the clips or behind the glass.

    it's just your luck Ken!! LOL That's what you get for buying those weird high end cameras.
     
  14. KenM

    KenM Member

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    But you don't have the tab, right?
     
  15. Eric Rose

    Eric Rose Subscriber

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    I will check when I get home and let you know.

    listen to the foot steps .............

    Ok, I'm home now and have checked the back. No tab.
     
  16. KenM

    KenM Member

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    Thanks Eric. I'm curious....

    BTW, we're hitting Lake O'Hara on Friday as part of the workshop. Should be a good time.

    We now return you to our regularly scheduled programming.
     
  17. KenM

    KenM Member

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    Just to let folks know, the patient is out of surgery - I ran one sheet of film from each Grafmatic through the camera, and they all came back clean.

    Light leak problems solved.
     
  18. Jorge

    Jorge Inactive

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    Hey Ken, if your luck runs anything like mine, you will need that little tab next week..you watch....:smile:
     
  19. KenM

    KenM Member

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    Hey, back off! I don't need any bad kharma right now. Only positive thoughts.

    All together now: Ohhmmmmmmmmmmm :mrgreen:

    I doubt if I'll need the hole, since it's for press shutters, of which I own none. 'Course, that means nothing down the road, but I tend to stick with only new lenses (too risky purchasing used, IMHO), so chances are, I'm good to go.