c-41 process: What went wrong here?

Discussion in 'Film and Processing' started by erikk, Feb 14, 2018.

  1. So I just finished developing a roll and it came out kind of weird. Some exposures seems to be just fine, but then you have some with dark lines on them. What could be the reason?

  2. Hi, most likely an accidental exposure to light somewhere along the line, possibly the camera back was opened part way through the roll.

    One tipoff is to examine the fog patterns near the sprocket holes - sometimes you can see an extra dark outline offset from the sprocket; these are likely due to light coming through sprocket holes in a layer of film wrapped over ABOVE the one you are looking at.

    If you can wind the film into a roll in such a way as to make the fog patterns line up, this would give you a good idea as to exactly where the fogging occurred.
    Wilmarco Imaging likes this.
  3. Agree with Bill C.
  4. Thank you for your replies!
    I'm pretty sure the camera back hasn't been opened.. Could it have happened in the development process?

    Also; I was kind of sceptical on the chemicals for this development, because I was not sure how they would performe because they haven't been used for some time. So are you sure this hasn't something to do with the chems? because I'm going to develop a roll later today (from a different camera) and I don't want the same to happen..

    View attachment Rullfail.eksempel002.jpg
  5. Certainly looks like light fogging.

    Are you sure the area where you loaded the developing tank was completely dark? A domestic room at night with the curtains drawn isn't dark enough.

    If you're using a changing bag, have you checked its condition and made sure it's light-tight?

    Are you using a plastic tank? If so are you sure all the parts and seals are there? Some plastic tanks allow infra-red to penetrate. Was the tank sitting in sunlight after being loaded?

    Incomplete bleach-fixing can cause the film to be dark, but this doesn't usually happen in patches, and looks different from what you've shown. The processing looks OK to me - other than the fogging of course.
  6. After a lot of years troubleshooting lab problems, the only thing that makes me real confident that a problem has been solved is to find an explanation where every detail can be explained. And even then, it's still only a high probability; if the following film is really important, I'd do a test processing run to be sure that the processing is ok.

    Now, in your case, I don't see that a good possible explanation has been found because 1) you don't think that the camera back was accidentally opened and 2) you didn't say that you found that winding the film a certain way makes the "fogged" parts line up.

    One thing I notice about the "fog" pattern is that it seems to have one sharp edge crossing the film, that seems to repeat every 8 sprockets, which looks like the same length as your normal frames. So there seems to be a repeat pattern correlated with film advance. Perhaps the camera has a leaking light seal on the take-up side, so every time you advance film the take-up is getting gradually fogged until you advance again? Now, I don't know if this pattern persists throughout the entire roll, so can't really say for sure; maybe it's just a coincidence?

    In any case, finding an explanation as to how the film might get fogged still doesn't prove that the chemicals are ok. I would suggest that, if the next roll is really important, then do a test processing run to verify that everything is ok. I might be inclined to load a fresh roll of film, shoot 3 or 4 test frames, then go in a darkroom to cut the film. Then just develop the short piece to see how it goes.

    All of the things that rodeo_joe mentions could be pertinent, too.

    Personally, if your next roll, which you said is from a different camera, is not critically important, I would probably just go ahead and process it. (This is on the assumption that you have successfully processed with this system previously.) I've never seen a strictly chemical problem that could affect the film in an off-and-on pattern like this. As a note, in C-41 only the developer is strictly critical. As rodeo_joe mentions, there could be problems with the bleach and fixer, but these can be corrected after the fact by rebleaching and refixing. Best of luck on your next roll.
  7. Thank you both for your replies. I've shot a roll with the same camera a couple of weeks ago without this problem, so I think the error might have happened in the loading of the tank. I loaded the film in what seemed to me complete darkness. My "darkroom" is a bathroom with a tiny window up high, that I first covered with a towel tight to the inner window frame and then I hanged a dark wool-blanket over the entire window frame. I didn't register any light at all. But could it be too bad of a solution for a darkroom? I will try to load my next roll in a room without windows.
  8. Also: the last pictures on the roll (the ones who was the first ones to hit the loading reel) have no light fog at all. During the loading of the film I went in different angles to try and load it as smooth as possible. So this is when it could have been exposed to some really low light if there were any
  9. AJG


    It can take 15-20 minutes of sitting in the dark to really tell if there are light leaks into the room you're working in, so that might well be the problem that you've had with this roll. A decent changing bag is well worth the money if you're going to do a lot of this and want to be sure that light leaks won't be a problem in the future. That also allows loading a tank any time instead of just at night. The Photoflex Film Changing Room is still being made and has a frame to support the bag and keep it away from your hands, film, reels, etc. We use these successfully at the community college where I teach.
    erikk likes this.
  10. Update: Just developed another roll in a different room, and it seems to be ok, at least there is no signs of the problems from yesterday. I really appreciate you guys taking the time to answer me!

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