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  1. #21
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    Try this:

    20mL/L of PaRodinal (or 2.5 paracetamol tablets 500mg, if tablets you'll need to let hydrolysis occur).
    100g/L of Sodium Sulphite
    30g/L of Sodium Chloride

  2. #22

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    Why the salt? (Sodium chloride)
    Salt has no positive function in a developer. You may get dichroic fog from it and it isn't washed out of the film by the stop bath and by this is transfered to the fixer where it reduces the action of the fixer. If you need something to tame fog, use KBr.

  3. #23
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    Sodium Chloride gives finer appearing grain, the recipe above is essentially a DIY Perceptol with Rodinal. The solvent action, combined with giving up a stop of film speed gives extra fine grain.

  4. #24

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    No, Sodium Chloride, AKA common salt does NOT give finer grain.
    Giving up a stop of film speed DOES give finer grain. Try the recipe without the salt and you will get the same results without the problems that salt in the developer introduces. There are some reasons why Kodak doesn't use salt in their developers. :-)

  5. #25

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    If you search for Microdol-X msds it will be found that this Kodak developer did contain sodium chloride.Sodium Chloride is usually mentioned on APUG as a mild grain solvent.
    Any evidence this is not right please give details.

  6. #26

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    Ok. I forgot about Microdol-X. They did use salt in that developer, but they have stopped using salt in developers because of the problems it may lead to.

    75g/L sulfite is a better grain solvent without the problems salt may give.

    It may be futile to talk about this since salt seems to be the ultimate stuff to use in B&W chemistry. It is a grain reducer, a fixer and a fog reducer. It's strange that nobody has used as a developing agent yet.

  7. #27

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    Cars rust faster in salt water than they do in fresh water. Salt is an oxidizing agent, not a reducing agent. Silver halides need to be reduced to metallic silver, so you need a reducing agent, not an oxidizing agent. That's why salt isn't used as a developing agent in silver halide photography.
    ME Super

    Shoot more film.
    There are eight ways to put a slide into a projector tray. Seven of them are wrong.

  8. #28

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    A first result from a new formula:

    Solution A:
    Dissolve 5g sodium hydroxide in 90ml water, add the contents of 16 capsules (8g) of Paracetamol/Tylenol.Stir with gentle heating in a stainless steel pot,filter through cotton wool, make up to 100ml.
    Store in a 100ml sealed bottle 7 days at room temperature to complete the hydrolysis and make the primary developing agent (p-aminophenol).
    Note, sodium hydroxide is caustic, hazardous:
    http://www.ccohs.ca/oshanswers/chemi...hydroxide.html
    It is sold as Lye or as Caustic Soda.

    LS-1c
    Water............................................. ................800ml
    Ascorbic acid (vitamin C powder).........................15g
    Solution A above............................................. .100ml
    Sodium Carbonate anhydrous..............................50g
    Water to................................................ .............1L
    Filter 2x through cotton wool.
    pH=10.4 +/- 0.1 Develop for Xtol 1+3 time from massive development table at digitaltruth .com

    Sodium Carbonate anhydrous may be replaced by Washing Soda.
    In the US, Arm &Hammer Super Washing Soda is close to monohydrate so take 50x1.2=60g Soda.
    In the UK, Washing Soda is usually the decahydrate so take 50x2.7=135g Soda.

    After 16 days in a 1L glass bottle the pH was still 10.4.The developer still worked,see attachment.
    I hope to report later how the developer keeps.

    Grain obtained was similar to that with Beutler developer.The large grain is because the specification that all ingredients should be obtainable from local shops means sodium sulfite cannot be added.
    Attached Thumbnails Attached Thumbnails LS-1c-1.jpg  

  9. #29

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    I goofed in the post above, the development time should be the same as Xtol 1+0, not 1+3.
    Now I just report that in a part full sealed bottle the developer is keeping well, at 52 days old its pH was 10.2 +/-0.1
    Attached is a pic developed in it after 54 days.

    The simplest explanation of what has been reported in the above posts:
    Paracetamol/Tylenol is hydrolysed by the caustic sodium hydroxide (handle with care) producing p-aminophenol derivatives.
    p-aminophenol is superadditive with ascorbate and regenerated by it,
    ascorbate is oxidized to dehydroascorbic acid,
    dehydroascorbic acid is orange,
    dehydoascorbic acid is a stronger acid than ascorbic acid and tends to cause a fall in pH unless well buffered.
    I don't think too much is public about ascorbate chemistry, it is post Film Developing Cookbook and other technical texts.
    Attached Thumbnails Attached Thumbnails LS-1c.jpg  

  10. #30

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    Continuing with this p-aminophenol/ascorbate formula,I noted that p-aminophenol/hydroquinone was used as early as 1902, see esp p197, Rodinal-Hydrokinone:
    https://archive.org/stream/cu3192403...ge/n0/mode/2up
    Later p-aminophenol/hydroquinone was used as a tropical developer,see Digitaltruth.com formulas for Kodak D-13.
    With more sulfite it was found in Ilford ID-44 ,I believe superseded by Perceptol.
    Thus p-aminophenol was generally replaced by metol which is more active.
    One would expect metol/ascorbate to be a more active developer than p-aminophenol/ascorbate tested here.

    My LS-1c has now developed 7 films and 600ml of the original 1000ml remains in the bottle.Oxidation has occurred as the pH has fallen from the initial 10.4 to pH=9.9 after 94 days.
    It still works, see attached pics.
    It appears the oxidation product of ascorbate is quite a strong acid to cause this pH drop.The solution has a distinct orange tinge.I will continue to monitor the pH.
    Attached Thumbnails Attached Thumbnails Alex.jpg   Sun on the lake.jpg  

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