I recently developed two 35mm films together in a tank. One, and only one of them, came out with artefacts on most (but not all) of the exposures – spots of uneven development that seem to originate from the film sprocket holes. Here's one frame from the roll for illustration:

enter image description here

(Negative digitized using a digital camera; you can just about discern the film sprocket holes behind the improvised white mask.)

I'm new to film processing, having developed ~10 films so far; I have never encountered this problem before, but it looks to me like an agitation issue. The procedure was as follows:

  1. Loaded two 35mm films in a Jobo tank, one reel on top of the other. The films were Ilford FP4+ rated at EI64 and Fomapan 100 rated at EI100. The film with the problem is FP4+; Fomapan came out perfect. I don't remember which film was on top.
  2. Developed in 1:4 Ilfotec DD-X for 8 minutes in 20°C, following Ilford's recommended agitation routine (4 inversions spread out over 10 seconds every 1 minute), except that at one point I had a bit of a lapse of attention and there was 1½ minutes between two successive agitations (and then only ½ a minute before the next one).
  3. Stopped in Ilfostop.
  4. Fixed with 1:4 Ilford Rapid Fixer, 2 or 3 minutes.
  5. Washed using Ilford's "fill tank with water, invert n number of times, pour water out, repeat, repeat and repeat" method.

My specific questions:

  1. What caused this artefact, and why does it appear on one film only?
  2. Would the order in which the films were loaded have an effect? Is the damaged one more likely to have sat at the bottom or at the top?
  3. What can I do to avoid this sort of thing in the future?
  • 1
    \$\begingroup\$ The films were both exposed in the same camera, yes? With similar storage/handling before/after exposure? Any other differences between the films before you got to the point of starting development? \$\endgroup\$
    – osullic
    Apr 5, 2019 at 9:48
  • 1
    \$\begingroup\$ Now that you mention it, I do remember that when I opened one of the film canisters, the film seemed to be "sticking to itself" in a way I had never experienced before. I don't know if it was the FP4 or the Fomapan, but I suspect the first. I didn't think much of it at the time – just thought this was characteristic of this type of film (which I had never processed before). Apart from that, same camera, storage and handling and both films exposed maybe a week apart. I should perhaps also add that the films went through airport security (carry-on bag) between exposure and development. \$\endgroup\$
    – Kahovius
    Apr 5, 2019 at 9:59
  • \$\begingroup\$ What kind of reels are you using? \$\endgroup\$
    – Blrfl
    Apr 5, 2019 at 13:13
  • 4
    \$\begingroup\$ Can you describe the specific error in text, to make it easier for people with similarly problems to find in the future? \$\endgroup\$
    – mattdm
    Apr 5, 2019 at 13:46
  • 1
    \$\begingroup\$ If one of the films was 'odd' out of the can, then it's likely the Foma. I love Foma (particularly the papers) but their film bases are not as good as Ilford's: they're often a significant pain to load. \$\endgroup\$
    – user82065
    Apr 5, 2019 at 14:27

2 Answers 2


This looks to me as if you have botched loading the film onto the spiral, so that two wraps of the film were touching or very close to each other. When that happens you tend to get marks on the negs where developer hasn't really reached them properly.

(I tend to get this with 5x4 negs processed in a mod54: huge negs like that are very flexible so if you agitate too much they can come out of the slots and end up resting on each other.)

  • 4
    \$\begingroup\$ I concur. This is a film loading error. I don't think you can save the damaged frames but -- do try re-fixing in normal room light. This procedure might provide some improvement. Do try! \$\endgroup\$ Apr 5, 2019 at 13:32
  • \$\begingroup\$ This is a good suggestion: if the dev didn't get to the frames then probably the fix did not either, so it is worth dunking them in fix for a bit to make sure they really are fixed, if you intend to keep them. As Alan says you can do this in white light. \$\endgroup\$
    – user82065
    Apr 5, 2019 at 14:26
  • \$\begingroup\$ Many thanks for your answer, @tfb! I'll make sure to pay more attention to loading the film properly next time. @Alan Marcus: thanks for the suggestion! I tried re-fixing today. The negatives didn't improve visibly, however. \$\endgroup\$
    – Kahovius
    Apr 6, 2019 at 19:58
  • 1
    \$\begingroup\$ PRACTICE with an old strip of film in the light, then in the dark . It should be loose feeling in the reel, give it a gentle push in towards the reel after every turn around the reel to see if it is binding up. You should be able to push it in and out a few millimeters. If it does not have the "right feel" then back it out a little and retry. After much practice and experimenting you will know the "right feel" \$\endgroup\$
    – Alaska Man
    Apr 6, 2019 at 22:01

Agitation... read about it [in the instructions that come with your film for manufacturer's recommendation], different films and developers need different amounts. Plastic reels and tanks aren't as good as SS for flow. [plastic reels have smaller openings, hard edges which disrupt flow patterns and though not originally referenced are more likely to cross contaminate though likely not an issue here]

  • \$\begingroup\$ OP mentions using FP4 and Fomapan in DDX. Your sentence is a non-answer with an unbacked assertion (plastic is worse than steel for flow). The neg looks like it was touching - a problem that aggressive agitation may actually make worse. Why not expand your answer to include what the proper agitation is for FP4 and DDX and how that would solve the negative-touching problem? \$\endgroup\$
    – OnBreak.
    Apr 9, 2019 at 19:49
  • \$\begingroup\$ Plastic is not as good as Stainless for flow, that is a fact not an assertion. Proper agitation is noted in the instructions for your film, I am not an encyclopedia, read your instructions. Additionally, the film was likely wet before loading as it stuck together and has characteristic marks. Solve the touching problem, get some good straight stainless reels and tanks and learn to load them. \$\endgroup\$
    – Davepix
    Apr 10, 2019 at 21:31
  • \$\begingroup\$ The Stack Exchange network would be completely useless if everyone answered in one word followed with the phrase, read about it. That's not really how anyone learns nor does it provide any value for future readers. I'll take your assertion at face value - you still haven't described how better agitation would overcome botched loading, regardless of reel type. tldr; your answer could be drastically improved. That's why I downvoted it. (It is customary for a downvote to come with an explanation. There, you have it.) \$\endgroup\$
    – OnBreak.
    Apr 10, 2019 at 22:21
  • \$\begingroup\$ Where do I say better agitation would overcome botched loading? It would appear there are are issues with the film loading as well as possible pre wetting in cartridge, I don't assume or assert anything but only make suggestions for the user to improve upon their skills. \$\endgroup\$
    – Davepix
    May 8, 2019 at 13:40
  • \$\begingroup\$ OP submit a problem. You submit a solution/answer. Ipso facto, your answer is a solution to OP's problem. OP's problem is most likely botched loading. Therefor, you assert that agitation (your answer) would solve OP's problem (botched loading). I believe this to be incorrect. Agitation, especially aggressive agitation, is not going to solve the wonky development caused by botched loading. \$\endgroup\$
    – OnBreak.
    May 8, 2019 at 16:23

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