What's Wrong with this Negative?

Discussion in 'Medium Format' started by adam_g|6, Jan 7, 2010.

  1. I am shooting with a Hasselblad 500 CM and 80mm F2.8 C lens. I self-develop the film then scan it. The last two rolls I shot, I've noticed some of the images have a slightly darkened side or sides. I've included a few examples below. I have not noticed this before, so I am wondering if this is a result of some sort of light leak or damaged light seal, or whether it's something as simple as lens flare that could be solved by using a hood when shooting. These images were shot wide open at 2.8 or possibly 4.0. I would be grateful if anyone could shed some light on what might be causing this. Thanks.[​IMG][​IMG]
     
  2. Sorry, attached are the samples I mentioned in the original post:[​IMG][​IMG][​IMG]
     
  3. It looks like a light leak from somewhere. Have you replaced the seals in the back recently?
     
  4. No, I have not replaced the seals in the back recently. I bought the camera and back from KEH one year ago, rated in EX+ condition. If it is a leaky seal, can anyone recommend a reputable repair service around New York City? Thanks.
     
  5. Those do not look to me as light leaks. They are too uniform and consistent in every frame. Usually the leaks related to old seals are in one side only (where you insert a dark slide)
    Can you see light sides in the negative on a light table? There is a possibility that the scanner holder is doing this.
    Could you scan an entire strip directly on the glass of a flatbed scanner to see if the problem is in the negative?
     
  6. Thanks Francisco. The problem is in the capture of the image, as these problems are showing up on the negatives. I agree they look quite uniform to be a light leak, but it's also worth noting that the problem is most pronounced in the 1st image, where I am shooting almost directly into the sun. Would shooting into any bright object such as the sun accentuate the effects of a light leak?
     
  7. Light leaks in hasselblad backs usually occur when you have a bright light on your left side, since it enters through the dark slide aperture. One way to test if you have a bad seal is to cover the darkslide slot with black tape.
    Do you have another back to test? Is the internal coating of the camera OK?
    If you take the back off and open the shutter in B, do you see anything strange?
    Also check the back without the darkslide in. Do you see anything unusual on the borders of the frame? Are they dark or shiny?
     
  8. This looks like a developing artefact..maybe you need to clean your spools?
     
  9. Another reason to discard light leaks is that you should see lighter areas not darker ones. It seems that something is blocking light maybe from internal reflections.
     
  10. Thanks for the suggestions. I keep the development equipment very clean but I will check the spools and perhaps switch it out. Francisco, I took the back off and opened the shutter in B, but didn't see anything out of the ordinary. The back appears to be in excellent condition as well, the borders of the frame are their original paint and do not reflect any wear or damage. I will shoot a roll of film with the darkslide slot covered and see what happens.
     
  11. If you want to eliminate light leak in the magazine, either from seal or loose fitting magazine, I suggest the following:
    1. Load a new film in very subdued light. Even in the darkroom under red light.
    2. Wrap dark cloth or strip of dark coloured paper around the magazine to cover the interface/join btween camera and magazine, so that absolutely no light can penetrate. Secure with tape if necessary. Effectively 'blind fold' the join.
    3. Go out and shoot off test film in bright, sunny conditions.
    4. Process in the same way you did with the problem film.
    If the flaw reappears on the test film, it is not a magazine light-leak problem.
    .
     
  12. This doesn't look like light leaks or a processing problem at all. I'm betting that you're not using a lens hood and that there is a strong light source striking the lens. This is flare. A lens hood will help, but will not eliminate all of it. Bottom line is that flare is something you have to live with when shooting into the light.
     
  13. This looks a lot like lens flare from internal reflections from not using a hood, or a very bright light reflecting off the internal surface of a hood. I've actually had that happen to me once. Newer bodies and lenses had made various improvements to try to minimize this effect (palpas coating for bodies and new internal design and new anti-reflection materials reducing stray light in the lenses for example). The darker strip off to one side is the shadow of something inside your camera that is blocking some of the scattered light.
     
  14. It's a light leak...
    Notice the defined line at the extreme left running top to bottom? It's the shadow from the "A12 back" main metal plate mating up with the body.
    A quick tip; don't leave your dark slides in the backs during storage. It keeps the light trap compressed which will eventually hold a memory. (No more light seal)
     
  15. Hey Gus. Would that light leak problem be with the film holder alone or at the interface between the holder and camera? What I am trying to get at is would getting a new A12 back solve this? Thanks.
     

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