Lightning strikes many, many times: film canister and static electricity

Discussion in 'Black and White' started by evan_goulet, Mar 3, 2011.

  1. Just an FYI type of posting here with regard to static discharges and their effects on undeveloped film. I had recently exposed a roll of Fuji Neopan 1600 at 3200. Thinking I was clever, and that I could skip a step, I left some of the leader hanging out the end of the canister so that I would have to pop it open prior to loading the film onto the reel. I hadn't ever done this before, and I don't know why I chose to do so this time. I pulled the film out of the canister st a good pace, extending my arm to full length in about 1 second. I loaded the film onto the reels and developed it as per usual.
    The results are shown below, and please excuse the grossly underexposed negative. Along the lower edge of the frame, you can clearly see the lightning strike pattern of the static discharge. The air in the room in which I was working was very dry; I would hazard a guess of 10% - 15% RH. This combined with the speed at which the film was dragged across the felt edge of the canister must have generated enough static to cause this discharge. It occurred about 8 times along the whole roll of 36 frames.
    So be forewarned, that in dry environments it is not a good idea to pull the exposed film back out of the canister by the leader lest you get Thunderstruck. Cue AC/DC!
  2. Thanks as in 40 years I have never had a static discharge show up except one time right where I removed the tape and it was on the unexposed end of the film.
  3. The god of film abuse has struck you
  4. I always load the reel from the leader sticking out of the canister. I don't pull all of the film out in one go though. I have never seen any static problems like this.
    The advantage of loading from the canister is being able to start the film into the reel in the light.
    in dry environments it is not a good idea to pull the exposed film back out of the canister by the leader​
    Certainly not at the speed you did it!
  5. Decades ago in the extreme low humidity of the artic north, we routinely advanced and rewound film very slowly to prevent static discharges. Fortunately, cameras then rarely had motor drives or automatic rewinds. Static discharges could appear as in the above example or irregular blotches.
  6. Jim, I was going to hit on the exact same topic.
    In extremely cold weather the same situation occurs. It is recommended that you advance film very slowly so as not to cause static discharge inside the camera. With older manual cameras with no advance drive motor this is quite easy. On my Elan 7 and several other models there is an option to use slow advance/rewind.
    Static discharge shows up prominently on the film as you have seen. It's a great catch and a great post for others to see.
  7. Here is a question to ponder: What is "safer"; Plastic or Metal carts? Metal is a conductor of electricity (which should ground the film to the camera / you) and plastic is an electrical insulator which can act as a static electricity accumulator. Would metal spools in a metal cart make it safer (clear path for the electricity to go, thus no arcing)?
    I ponder this because I bulk load. I may be able to prevent it by design. I have plastic carts and metal carts. All have plastic spools, making the potential safety of the metal case useless. Plastic is probably safer because of no ability to conduct electricity (but could enable the build up during use).
  8. Yep..had that the cans...cut off the tail. It is not an uncommon problem.
  9. Lots of that sort of problem here back in the 70's when I was doing microfilm in a lab. Humidifiers and dryer sheets are/were the answer. (central Washington State). Winter is dry and cold RH in a heated house is really low.
  10. I have loaded reels from the canisters in dry weather without any problems. I think your problem is the speed at which you pulled it out. Pulling 5 1/2 feet of film out in one second is equivalent to pulling the film along at 3 3/4 mph, a little fast if you ask me. I use Paterson reels, and I always allow the ball bearings to pull the film out at whatever rate I twist the sides. It might be harder with SS reels, but if you take it slow, you should be fine.

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