Advice on vertical bands appearing on negs at random. (ETRC Bronica 120 back)

Discussion in 'Medium Format Cameras and Accessories' started by Sepanta, Mar 22, 2014.

  1. Sepanta

    Sepanta Member

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    Dear Members,
    I would really appreciate some feedback and help identifying the issue here. At first I thought it was some kind of reflection off the prism or filters, but I have tried both on eye level and waist level finders, removed the filters and shot with the lens hood to try the process of elimination, but the problem still persists.
    Can anyone help me identify why I get these thick bands at seemingly random exposures? out of 15 exposures, about 5 appear with the band at not particular order, seemingly at the exact position on the neg
    Thank you so much
    Sepanta (noob)
     

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  2. fretlessdavis

    fretlessdavis Member

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    Check the light seals on the back. I know the ETR-C can't interchange, but there are light seals on the back door that can gum up.

    Interesting issue, though, looks like what my one of my ETRS backs was doing when the light trap for the darkslide was thrashed.
     
  3. DWThomas

    DWThomas Subscriber

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    Looks like a light leak problem. Often the light is hitting the film between the supply or take-up spool and the film gate. As such, it's the frame before or after the actual picture that gets exposed and the band may go out to the edge of the film rather than being masked to the frame area. You might check for that. In my (thankfully) limited experience the problem may not appear on every frame because of variations in the amount of ambient light and/or the angle the light hits the camera. If the leak is very small, even the amount of time between shots makes a difference.
     
  4. StoneNYC

    StoneNYC Subscriber

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    The green ones look cross processed, how did you make them green?

    And yes I say light leak...
     
  5. AgX

    AgX Member

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    In the samples 1,3 and 5 there are above, right of center identical sharply confined streaks or patches that rather resamble images of specular light than a effect of leakage.
     
  6. Dan Daniel

    Dan Daniel Subscriber

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    I findit helpful to put the negatives back in the camera to find where light could be coming from. And DWTHomas is probably right- the leak is happening when the frame is not at the actual film gate. The leak happens when the film is coming off of the film spool or onto the take-up spool. The crisp line on the lower edge makes me think this.

    So position the negatives in the camera as if it was being exposed and I bet the trouble area becomes clear.
     
  7. markbarendt

    markbarendt Subscriber

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    I got this same problem on my RB and it was the light seals for the dark slide. Took a while to figure out that when I pulled or replaced the dark slide the stripe appeared.
     
  8. Sepanta

    Sepanta Member

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    Thank you all so much,
    It makes total sense that the frame would be exposed from to the supply to the take up and that the line would appear depending on the ambient light and how long the film would he in position. I will check for leakage when this spool is finished.
    I would like to send the camera in to get the seals re-done - any recommendations? I am prepared to send the body in via post as I am in D.C and there are not many good camera shops around.
    Thanks again,
    Sepanta
     
  9. Sepanta

    Sepanta Member

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    Yes, they were a lomo film that I got cross processed!
     
  10. Dan Daniel

    Dan Daniel Subscriber

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    Replacing seals is not very difficult. I would contact Jon Goodman and see if he has a kit for your camera. Here's a recent classified he ran here-
    http://www.apug.org/forums/forum379/126441-light-seal-kit-clearance-minolta-autocord-others.html

    A page by him with a variety of instructions-
    http://www.kyphoto.com/classics/sealreplacement.html

    He'll provide instructions and tools for doing it yourself. And it will probably run no more than $10 or so. He pretty well created the light seal replacement game, then has been driven nuts by other people ripping him off (even copying his instructions to send out with their kits). Very upright guy, no worries about sending him cash or check. Save your postage and repair money for when you really need it (and maybe look for film other than Lomo which tends to be overpriced, isn't it?).

    EDIT: I see his ad says that he has stopped with Bronica kits. Well, contact him anyway. He might be able to suggest another kit that will have what is needed. Trimming lengths to fit is quite easy.
     
    Last edited by a moderator: Mar 23, 2014
  11. fretlessdavis

    fretlessdavis Member

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    Get a kit from Jon Goodman. It's not too difficult to do yourself. I redid one of my 120 backs without a template or kit, I just cleaned out the gunk in the light trap on the back door, and replaced it with wool yarn I had left from redoing my MX and ME Super. If you haven't done it before, a kit would be very useful.

    If you're not confident you can do it yourself, look around at some camera dealers before sending it off. I got my second ETRS body in very good shape (rated BGN since the leatherette was pealing in a couple places) from KEH for less money than it was going to cost for a CLA on my first one that came from eBay.
     
  12. AgX

    AgX Member

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    Covering all respective slits with black electrical tape and testing on two strips of 35mm film should yield a result without even spoiling a whole 120 film.
     
  13. MattKing

    MattKing Subscriber

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    My camera repair person charges me very little to replace foam seals on things like Mamiya RB backs if I first do the grungy work - clean our the old seals!
     
  14. hsandler

    hsandler Member

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    If it is an ETRC, the back is not removeable. Presumably there is no slot for a dark slide. Since you are not changing backs mid roll, you could just wrap the light seal areas in black electrical tape after loading the film, and you should be ok until the end of the roll.