Static or ghost? A high-speed conundrum.

Discussion in 'B&W: Film, Paper, Chemistry' started by Robert Kennedy, Jun 7, 2003.

  1. Robert Kennedy

    Robert Kennedy Member

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    Over the last month or so, I have shot about 5 rolls of Ilford 3200. Some have been shot at 3200 some at 6400.

    On all of them, I got the weirdest thing.

    It was a line of irregular small dots peppering the film roughly in the middle of the roll. They were relatively faint, and didn't even come near the edges of the frame. So a light leak didn't seem likely. Besides the same exact thing happened on TWO different cameras. My N80 and my FT2.

    Now, after I dismissed the idea of selling the photos as "evidence of ghosts" (weird orbs and lights on film are adored by ghost hunters...I guess bad processing at the mall pays off for some), I wondered if it was simply a bad batch of film from Ilford. I bought all the rolls from B&H at the same time so it was possible they all came from the same lot. But that seemed odd too. Very unlikely.

    These "dots" were also odd in that they went for a while, stopped, and then started again. No real pattern though.

    In fact here is an example. Yes, the picture is crummy, but it shows the "dots" really well.

    [​IMG]

    Now keep in mind this was ONLY happening with the Ilford 3200. Anything else that was slower did fine.

    I finally asked at the lab.

    They said it was probably static. Which makes a lot of sense.

    First off, it is VERY dry here. Static is the ban of Arizona.

    Secondly, the rewind on my N80 is set at the fastest speed, and when I rewind on my FT2 I rewind very fast. Static would explain the problem. And only high speed film would record it like it did since the senstitivity is so high.

    So that is my theory. That it was static and I need to slow down a bit. This also occured ONLY during the dryest time of year. Other times I have shot fast film it hasn't.

    So am I spot on here or am I missing something? I could use some reassurance since I am tired of touching up my images!
     
  2. MikeK

    MikeK Member

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    i have seen static marks on film and they look more like irratic stars/cobwebs rather than blobs. I was shooting 72 exposure HP5 with a 5 fps motor drive in very dry and cold conditions. The static marks were all over frames and not in a straight line.

    Mike
     
  3. Robert Kennedy

    Robert Kennedy Member

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    I''m still thinking static. What else could it be? It shows up on NOTHING else. And it shows up on two different cameras.

    Whatever it is, it only affects the high speed film.
     
  4. mvjim

    mvjim Member

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    Don't know if this is related or not, but on another on-line forum this same problem was posted. Same type of markings but on Tri-X film.The one thing that was common to both cases was that the film was also purchased from B&H. And I agree with Mike, I have seen many cases of stacticed film and the marking are "spark" or star shaped.
     
  5. Robert Kennedy

    Robert Kennedy Member

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    What could it be then? It runs in lines along the film, peters out, then starts again. And since it is in the middle I can't understand how it could be a light leak....
     
  6. mvjim

    mvjim Member

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    Robert,
    If you have any of the film left you might want to try developing some of it w/o run ning it through the camera and see if it is a bad batch of film.
     
  7. Robert Kennedy

    Robert Kennedy Member

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    I may have one more roll left. I'll have to check.

    Weird stuff.

    Ah hell...I'll just sell it all to Weekly World News as evidence of life after death and buy myself a new lens... :smile:
     
  8. glbeas

    glbeas Member

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    It does look like a static discharge from an edge in the camera to me. The fact that it starts and stops then starts again says the charge builds, arcs to depletion then repeats the cycle with a slightly different discharge point each time. Might try finding an antistatic wipe that will be safe for the materials in the camera body. Anyone know of one?
    I'm familiar with the static effects available in Arizona, having worked there a year at a newspaper in Casa Grande. When rewinding rolls of newsprint from butt rolls to make a bigger roll I'd need to measure the diameter occasionally while running and would draw a two to three inch spark off the frame of the rewinder. What is that, thirty to fifty thousand volts it takes to jump a three inch gap?
     
  9. Robert Kennedy

    Robert Kennedy Member

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    WOW!

    That is amazing!

    Casa Grande has a newspaper!

    :smile:

    I actually shot two rolls last night in my ft2 and did a VERY slow rewind on both.

    See how it works.

    I'm thinking if it is static it is a VERY low charge. But enough to pop up on the highspeed film.
     
  10. Ed Sukach

    Ed Sukach Member

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    I've been thinking of this ... It really looks more like some sort of anomaly caused by localized "stress" ... but, unless there is a wheel or some sort of spring pressing against the center of the film (pressure plate problem?) - I'd go with static electricity.
    It doesn't take much to produce visible static electricity. If I allow my eyes to become fully acclimated to darkness, I can see a visible static electricity discharge when peeling the tape from 120 film, prior to loading the film on the developing tank reel. Faint, but visible. In all the developing I've done, I've never seen *ANY* degredation of the image from that discharge.

    One thing you might try is **dilute** dishwashing liquid ... or, if you want to stay purely photographic, working stregth wetting agent - I use Edwal LFN, or Kodak PhotoFlo. Moisten a tissue and wipe it across the surfaces in contact with the film, and let it dry. That should provide enough lubrication to prevent electron stripping - static electricity.
     
  11. Ole

    Ole Moderator Staff Member

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    Ed,
    The flash from the tape isn't static electricity. It's triboluminescence - an entirely different phenomenon. And it doesn't hurt, except when you try to spell it.

    I've seen "lightning tracks" on film used in very dry weather - in Africa, not Norway. The marks on Robert's film could well be that. The start/stop with irregular spacing is about what I would expect...
     
  12. Robert Kennedy

    Robert Kennedy Member

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    It can't be stress marks. The negs are intact looking (no dents, dings, etc.) and the problem occurs with two seperate cameras. O.k. Both are Nikons but they are almost 30 years apart in age. So it can't be that.

    Although the point about visible discharge is worth noting here. We are talking about film rated at 6400. The same shots with 400 or 100 speed would be pitch black. This could be a regular occurance, but only a problem when I am running such funky film through the cameras.
     
  13. Les McLean

    Les McLean Subscriber

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    Have you considered processing marks? I've seen some strange marks on films after they have been processed in deep tanks in labs. I've shot Delta 3200 at speeds from 800 to 25000 ISO and have never had any strange effects such these. I have good contacts in Ilford UK so I'll send your original post with the attachment to the technical department to see what they make of it. I'll keep you posted.
     
  14. Robert Kennedy

    Robert Kennedy Member

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    Thanks Les.

    It could be processing marks I guess, but the rolls were shot over a period of time and developed at different times.

    Then again who knows.

    I am sure though that static caused by dry-air is not much of a problem up where you are at.

    :smile:
     
  15. shooter

    shooter Member

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    What way does your shutter open? Horizontally or Vertically? This might be light leaking through shutter blades at odd times or with exposure to bright light sources. Just a small amount going through, enough to expose the high speed film and not enough to expose the slower film.
     
  16. Jorge

    Jorge Inactive

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    Aha...I finally rememebered where I have seen this, those look like emulsion scratches caused by the felt on the cartridge. Usually a piece of dirt gets caught in the felt and when you rewind, specially at high speed the dirt scratches the emulsion.
    You can tell because it is intermitent but it is on a straight line. Of course, this happens right down the middle of the roll, if it was at the edge then it would not be the curse of the photo Gods....:tongue:
     
  17. Ed Sukach

    Ed Sukach Member

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    Oh. First time I've heard of triboluminescence. In what way does it differ from a static electricity discharge? - In three words or less ...
     
  18. Jorge

    Jorge Inactive

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    tribo...what?..what the heck is that??? never heard of this, please explain!
     
  19. Robert Kennedy

    Robert Kennedy Member

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    Is Triboluminescence what you get when you rub two trilobites together?
     
  20. Ole

    Ole Moderator Staff Member

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    Triboluminescence isn't electric, it's chemical (well - physical really, but not electrical). It refers to a substance giving off light when subjected to mechanical stress. It's a lot more common than you'd think, but the light is so weak it's rarely noticed. As far as I know, all types of sticky tape do this to some extent. But we tend to notice those we tear in the darkroom.

    I had a feeling I would be asked to explain this...
     
  21. Robert Kennedy

    Robert Kennedy Member

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    Sounds sort of vaugely similar to sonoluminescence.
     
  22. Ole

    Ole Moderator Staff Member

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    Quite correct - it is so similar that some consider sonoluminescence to be a special case of triboluminescence. A strong case can be made for the tape flash being sonoluminescence, as the source of the flash is probably microbubble collapse.

    :wink: