Saturday, 16 May 2015

Contaminated by wetting agent?

Developed in RO9 but it is not the developer.
When something unexpected happens while you are processing your negatives, it takes a bit of time to get your head round it. This happened while I was processing a number of rolls of film in R09 and using it's special brother.

 The problem has shown it's self by producing very blotchy negatives affecting two rolls of the six film developed. When this happens in a run of developing it is difficult to work out what circumstances are different enough to point a finger at.

Please bear in mind that the elimination process was written after I discovered the culprit.

Fomapan 100 negatives developed in RO9
Process of elimination:

  1. So where to start? It is fortunate that the negatives involved were not the ones processed in the RO9 special. The RO9 developed one's were. This made the investigation more straight forward in that I have a better understanding of how RO9 works.
  2. Was it the developer? It was made up seconds before it was used in the usual way.
  3. What about Stop and Fix? Both were freshly made up minuets before use. So it cannot be one of the three main players? As they are all fresh.
  4. OK what about the method? No difference there either I used my usual inversion sequence.
  5. Processing tanks? Well I did press a tank into use that I have not used in a long time because of the quantity of film that needed to be developed.
  6. Could that be the answer?
  7. Did it affect one make of film in particular? No it did not, again this could have been a fortunate coincidence in that a roll of FP4+ and Fomapan 100 show the same affect. If it had only happened to one make it could have been construed as a manufacturing fault.
  8. Water? It was fresh and clean and there had not been any notices to say there was a problem with the drinking water.
  9. That leaves wetting agent? Hold on now that points to something I noticed when I was using PMK Pyro some years ago, I had a roll of film with the same sort of pattern. I put it down to the developer which I have
    Film FP4+ developed in PMK Pyro
    not used since. Thinking back to that time I had noticed that every time I opened the dev tank to pour out the developer there were a lot of bubbles in the top. That looked soapy and diminished with each step of the process which would suggest developer. I did speak to a number of other photographers at the time who suggested it was a developer fault. Although I stopped using the developer substituting it for ID11 and the problem disappeared was not convinced at the time. I changed how the kit was washed after each processing session. After a while I also stopped adding wetting agent to the tank. Using a different tank with it already added. Dunking the reel in by it's self and then soaking the reel in a bucket of water with a good resin afterwards.
Looking back I think when I pressed the other developing tank into use I mistakenly picked up the one I had been using for wetting agent. The resulting blotchy pattern is the result of its contamination.

This print was made from the same contaminated
Negatives. note no blotchy marks.


Having eliminated all the other possibilities and no matter how silly it may sound the wetting agent is the culprit in this case. It has this time affected nearly all the frames on each film, when it happened some years ago (after checking the negatives) only certain frames showed signs of being blotchy. Which would indicate a weak contamination of the film process. This is only the second time I have had this problem in all the years I have been developing film. It just goes to show that something as innocuous as soap can cause so much trouble if it is not washed away conclusively after every processing session when added to the developing tank. My suggestion is to put wetting agent in a separate container and add the reel and film to it and not the other way round.

This picture shows that the blotches are prominent
In the sky but not the foreground.

When printing the affected negatives you cannot see the blotches when looking down the focus finder. Even though the contact prints show it quite clearly.

All the photographs that appear with this article were printed from the dodgy neg's. As I mentioned not all suffered the soapy demise. 


  1. Holy Smokes! You solved my problem! I'll have to test but it sure looks like it and what's more I've been adding 3 drops of wetting agent to the developer for 120 films. (for air bells) No more of that. Some Pan-F I developed really shows this texture. Thank you.

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  3. Well done on your detective work, Mitch. I have read (Apug/Photrio I think) that wetting agent should be kept well away from reels, to prevent just such contamination. After washing, I take the film off the reel before dunking it (gently) in a separate container that I keep just for the wetting agent stage.

    Who would think such a few drops of that stuff, heavily diluted as it is, could have such an effect?!

    1. Hi Michael thank you for your comment. Like you I did start using a separate container with wetting agent in and it did make a difference. I have now moved on to a different method that requires no wetting agent at all.