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  1. #1

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    Fine grain developer from Paracetamol/Tylenol

    Ingredients p-aminophnenol/sulfite are a curiosity from history.

    First I made some clear PaRodinal:
    http://photo.net/black-and-white-pho...g-forum/00UxmB

    20ml 10% hydrochloric acid was added to 50ml clear PaRodinal,giving a precipitate (p-aminophenol) which was allowed to settle 24hrs,the clear liquid decanted and the precipitate filtered off,being left overnight for the liquid to soak through the filter paper.
    48g sodium sulfite was dissolved in 600ml water(=80g/L sulfite).The filter paper and contents were soaked in this solution,the precipitate soon dissolved at room temperature.

    HP5+ was developed 20m 20C in this solution,I call it PRS-1 (PaRodinal Solvent),see attachment (a 0.1 in square section of negative),this is from EI=320.
    For comparison I don't have HP5 in Xtol so give Tri-X in Xtol at EI=400.

    Evidently p-aminophenol/sulfite works but more work woul be needed to see if it is possible to make a developer giving as fine grain as metol/sulfite.
    Thanks for comment.
    Attached Thumbnails Attached Thumbnails Tri-X Xtol-1.jpg   PRS-1 a-1.jpg  

  2. #2
    Ian Grant's Avatar
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    Original Rodinal is p-Aminophenol in sulphite with no free Hydroxide, so similar but with a much higher level of sulphite.

    The sulphite in Rodinal is generated by adding Potassium Hydroxide to Potassium Metabisulphite the difference beteween Calbe/Orwo R-09 and agfa (post 1963) Rodinal is the first has no free hydroxide, the second uses less developng agent at a higher pH wit an excess of Hydroxide.

    Mees did similar in his early days at Wratten & Wainwright when he worked on p-aminophenol around 1908

    Ian

  3. #3

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    The following quote is by Bill Pierce and appeared as Rodinal Re-jiggered in Popular Photography (Sept 1966).

    "When diluted 1:100 with 7.5% sodium sulfite solution, Rodinal may be used as a deep tank developer. Replenish with 1 ml of Rodinal for each roll of film. The replenished solution keeps for one month. Decrease development times by 20% from those used for Rodinal diluted with water. Used in this manner, Rodinal-sulfite becomes a medium fine-grain developer producing prints with very clean highlights."
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  4. #4

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    Yes, this is interesting. I think the issue in practical use is whether the developer lasts long enough, and whether the developing times are too long for some to be practical. But that p-aminophenol can be made to act in different ways depending on the formula (just like metol or phenidone) is good to know. I have read somewhere that using Rodinal at much colder temperatures (16 C) also gives finer grain, and the converse is of course also true. It is also super-additive with ascorbate etc. That out of all the possibilities we have only Rodinal as a widely-used developer, is then strange given how many metol and phenidone formulas there are. I can only guess that it has to do with cost and/or a lack of longevity. Do we have any indication how long the original Rodinal (not the replenished) lasted? My understanding is that it was used as a stock solution, not single shot concentrate that had to be diluted. With those sulphite levels, the sulphite would be the major contributor to cost, not the developing agent. Which might explain why it wasn't pursued commercially.

  5. #5
    Ian Grant's Avatar
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    There's no evidence that using Rodinal at different temperatures has any effect on the grain size in a negative. However the hydroxide in Rodinal can have a softening effect on the surface of the emulsion causing micro reticulation, this only occurs when temperature variations are excessive during processing and is more likely to happen at higher temperatures. The results is prints with more apparent graininess.

    Rodinal has always been diluted, I posted the pre-WWI instructions here on APUg, and by 1907 other companies wre making similar p-Aminophenol concentratrated developers, like Ilfor Certinal, I'm not sure when Kodak introduced Kodinol but it was before WWII (it was never made or sold in the US).

    Ian
    Last edited by Ian Grant; 05-29-2013 at 04:00 AM. Click to view previous post history. Reason: add

  6. #6

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    Ian,
    Just out of interest,I know there was a formula for Rodinal that got "liberated" in 1945.Do you know if yet earlier versions of Rodinal were the same or was it different at first?Was there ever a version comprising only p-aminophenol and sulfite?
    Jerry,
    I would guess the formula you quote must be slow acting as Rodinal 1:100 at its natural high pH takes about 20min to develop a film.Perhaps that is why that formula you quote is not well known.
    Dorff,
    IDK why p-aminophenol was abandoned in favor of Metol.It was about 120 years ago, the information may be lost.
    A good idea of yours to try to speed up development with ascorbate.I could try using the p-aminophenol made from 50ml PaRodinal (=3g original paracetamol/tylenol) to replace the phenidone in Pattons E-76.

  7. #7
    Ian Grant's Avatar
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    Alan, Agfa stated over 100 years ago that Rodinal was an alkali salt of p-Aminophenol in neutral sulphite and water with no excess of caustic alkali (hydroxide). Calbe's R-09 still meets that criteria but in the 1930's an anti oxidant was added it was also a mild wetting agent.

    Agfa may have increased the level of Sulphite with the uptake of 35mm in Europe to help produce finer ghrain but they always foremd the sulphite by adding Hydroxide to Metabisulphite. Fine grain developers became more important in terms of research in the mid to late 1920's.

    Metol was probably cheaper to produce and developers could be sold in powder form, that may not be possible with p-Aminophenol which was also Patented by Agfa.

    It was recommended by Agfa themselves to dilute Rodinal with Sulphite solution 5-10% (cryst, half that for anhyd) to greatly extend the keeping properties, and again first publishe over 100 years ago.

    Ian

  8. #8

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    Quote Originally Posted by Alan Johnson View Post
    Ian,
    Just out of interest,I know there was a formula for Rodinal that got "liberated" in 1945.Do you know if yet earlier versions of Rodinal were the same or was it different at first?Was there ever a version comprising only p-aminophenol and sulfite?
    Jerry,
    I would guess the formula you quote must be slow acting as Rodinal 1:100 at its natural high pH takes about 20min to develop a film.Perhaps that is why that formula you quote is not well known.
    Rodinals formulation has undoubtedly changed since its first introduction. So there have probably been variations before the 1945 formula.

    Remember that the developing times are 20% shorter with added sulfite so that 20 min becomes 16 min. With the high salt concentration there is no reason that higher developing temperatures cannot be used. Or for that matter a higher concentration say 1+49. There are lots of variations possible. Both Rodinal and sodium sulfite are cheap enough to use in a one-shot developer. I used this method years ago and it worked very well. Finer grain and beautiful prints.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  9. #9

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    A study by M. H. Dickerson presented in Haist's book showed the threshold alkalinity for p-Aminophenol to be 9.35 (compared with 7.25 for Metol, for example), which would be fairly incompatible with fine grain development. Perhaps the general trend toward fine grain developers helps explain why p-Aminophenol was not ultimately more widely used as a developing agent.

    Ian could probably comment on a note in Anchell/Troop (FDC) regarding later versions of "Agfa Rodinal" (or at least Agfa Rodinal as it existed at the time that book was written). Among other things they say it contained a restrainer and speculate this must mean p-Aminophenol was no longer the sole developing agent in the formula (presumably based on the low fog characteristic of p-Aminophenol on its own.

  10. #10
    Ian Grant's Avatar
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    Michael, in a 1930's Agfa Patent they were using a wetting agent sodium dibutyl-napthalene-a(alpha)sulphonate in a p-Aminophenol developer to overcome uneven development. This also has anti-oxidant properties.

    It's known that Sodium benzenesulfonate was used by Orwo & Foma in R-09 from Soviet and Polish publications. Kodak, Fuji and Ilford all have Patents relating to Sodium benzenesulfonate or it's derivatives, citing them as anti-oxidants and wetting agents. These componds aren't developing agents.

    There's an issue of what is or isn't a developing agent, a compound might have an ability to develop a very weak image (in an alkali solution), or it might provide an additive effect to a developing agent. Sodium benzenesulfonate or it's derivatives have been used alongside colour developing agents to increase solubility and promote more efficient development.

    Ian

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