rule of thumb

Discussion in 'B&W: Film, Paper, Chemistry' started by RalphLambrecht, Mar 2, 2012.

  1. RalphLambrecht

    RalphLambrecht Subscriber

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    is there a general ruleof hoe developer dilution affects fil characteritics likr\e grainyness, sharpnessetc, and what is the logic behind it?
     
  2. Ian Grant

    Ian Grant Subscriber

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    No unfortunately there isn't.

    Grain gets coarser and sharpness and acutance improve with dilution with developers like D76/ID-11 and Xtol as the Sulphite level drops however some of the Universal developers like PQ Universal the grain gets finer with dilution as the Carbonate (& hydroxide) gets diluted.

    Ian
     
  3. zsas

    zsas Member

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    Ian - so using that train of thought in the non-PQ's, does higher amounts of sulfite make grain finer?
     
  4. Ian Grant

    Ian Grant Subscriber

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    Yes it can, but that also applies to PQ developers like ID-68 (Microphen) and Autophen (a PQ version of ID-11/D76).

    Some Geraman photographers would add extra Sulphite to dilute Rodinal ti give finer grain, this was actually once a recommendation (pre WWII) from Agfa to prolong tray/tank life once diluted. We forget that at one time Rodinal, and it's clones like Certinal (Ilford), Azol (M&B) were used for prints as well as films although not a such great dilutions, by the time Kodinol (Kodak UK) was released these p-Aminophenol developers were only being used for films.

    The downside to increased Sulphite is less distinct grain and a loss of sharpness and acutance so it's about getting the best balance.

    The Agfa 44 (Agfa Ansco/GAF 17) and Adox Borax MQ developers drop the Sulphite level to 80g/l compared to the 100g/l of ID-11/D76 and this gives better sharpnedd & acutance, the ration of M to Q is dropped and there's a slight improvement in grain as wll, as a consequnce tonality is improvered.

    Ian
     
  5. RalphLambrecht

    RalphLambrecht Subscriber

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    any possible explanationwhy?
     
  6. Ian Grant

    Ian Grant Subscriber

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    Yes Sulphite is a mild silver solvent, this helps keep the grain size down. Two extremes would be D23 which is just Metol and Sulphite and is Beutler which has Metol, Sulphite and Carbonate.

    So:

    D23
    Metol 7.5g
    Sodium Sulphite (anhyd) 100g
    Water to 1 litre

    Beutler
    Metol 1g
    Sodium Sulphite (anhyd) 5g
    Sodium Carbonate (anhyd) 5g
    Water to 1 litre

    D23 gives relatively fine soft grain with mediocre sharpness, Beutler gives coarser grain with excellents sharpness and acutance. Because of it's higher pH Beutler requires a much lowerer level of developing agent.

    ID-11/D76 etc lie somewhere between the two with a milder alkali and gives a relatively balanced compromise of grain, sharpness, acutance and tonality.

    Ian
     
  7. Gabino

    Gabino Member

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    Ian, where does xtol fall into this scheme of things? My first thought is that it would fall close to D76/D11.
     
  8. Ian Grant

    Ian Grant Subscriber

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    In terms of the Sulphite yes close to ID-11/D76 but other factors come into play as well like the choice of developing agents as well as the pH.

    Ian
     
  9. RidingWaves

    RidingWaves Member

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    "We forget that at one time Rodinal, and it's clones like Certinal (Ilford), Azol (M&B) were used for prints as well as films although not a such great dilutions, by the time Kodinol (Kodak UK) was released these p-Aminophenol developers were only being used for films."


    Ian, could you direct me to a Rodinal formula for prints? I've been looking for one, old one is fine.
     
  10. Ian Grant

    Ian Grant Subscriber

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    Rodinal, it's the dilution that's important and it's not so economic these days, you'd need to use it 1+10 to 1+15.

    The Rodinal (old type) formula in most moder books is wrong as they use p-Aminophenol Hydrochloride. Rodinal has always been made containing the p-Aminophenol free base right from it's introduction. I posted some suggestions in the articles section under Modern Rodinal equivalents.

    Ian
     
  11. RidingWaves

    RidingWaves Member

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    Thanks Ian, I'll have a look, but with Parodinal being fairly easy for me to make I was thinking of trying it out, those dilutions will be my starting point. Thanks!
     
  12. RalphLambrecht

    RalphLambrecht Subscriber

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    can you post a formuls for parodinal? i couldn't find one.
     
  13. dmb

    dmb Member

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  14. Ken Nadvornick

    Ken Nadvornick Member

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    I have never been able to get that sulfite ratio of 200 grams/liter to come even close to dissolving completely, even at elevated temperatures. Cutting that ratio in half (25 grams/250 ml) has always seemed to work out much better.

    Had a small (thin plastic) drinking water bottle holding an older batch. Let it sit for about a year - maybe - just to see what would happen over time. The hydroxide finally ate a hole in the side. Dripped solution, which immediately turned blackish, all over everything. What a huge mess. I shoulda' known better...

    :sad:

    Ken
     
  15. Ian Grant

    Ian Grant Subscriber

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    Concentrated solutions of Sulphite are best made from Sodium or Potassium Metabisulphite and Hydroxide.

    Ian
     
  16. RalphLambrecht

    RalphLambrecht Subscriber

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    Sodium sulfite
    From Wikipedia, the free encyclopedia
    Sodium sulfite


    anhydrous

    hydrate
    IUPAC name[hide]
    Sodium sulfite
    Other names[hide]
    Hypo clear (photography)
    E221
    Identifiers
    CAS number 7757-83-7
    PubChem 24437
    ChemSpider 22845
    UNII VTK01UQK3G
    RTECS number WE2150000
    Jmol-3D images Image 1
    SMILES
    [show]
    InChI
    [show]
    Properties
    Molecular formula Na2SO3
    Molar mass 126.043 g/mol
    Appearance white solid
    Density 2.633 g/cm3 (anhydrous)
    1.561 g/cm3 (heptahydrate)
    Melting point
    33.4 °C (dehydration of heptahydrate)
    500 °C (anhydrous)
    Boiling point
    Decomposes(separate (substances) into constituent elements)
    Solubility in water 678 g/L (18 °C, heptahydrate)according to wikepedia, the solubility of sodium sulfite in 18cwater is above 600g/l
    Sodium sulfite
    From Wikipedia, the free encyclopedia
    Sodium sulfite


    anhydrous

    hydrate
    IUPAC name[hide]
    Sodium sulfite
    Other names[hide]
    Hypo clear (photography)
    E221
    Identifiers
    CAS number 7757-83-7
    PubChem 24437
    ChemSpider 22845
    UNII VTK01UQK3G
    RTECS number WE2150000
    Jmol-3D images Image 1
    SMILES
    [show]
    InChI
    [show]
    Properties
    Molecular formula Na2SO3
    Molar mass 126.043 g/mol
    Appearance white solid
    Density 2.633 g/cm3 (anhydrous)
    1.561 g/cm3 (heptahydrate)
    Melting point
    33.4 °C (dehydration of heptahydrate)
    500 °C (anhydrous)
    Boiling point
    Decomposes(separate (substances) into constituent elements)
    Solubility in water 678 g/L (18 °C, heptahydrate)