"d76" type developers - dilutions for "one-shot" use ?

Discussion in 'B&W: Film, Paper, Chemistry' started by pdeeh, Jul 25, 2013.

  1. pdeeh

    pdeeh Member

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    Reading around on developers, I note that there's a "family" of D76-type, based on MQ & with 80-150g (ish) sulphite/litre.

    Dilutions for "one shot" use are commonly given for D76, but I wondered whether others in the "family" are also suited for 1:1 (or greater) dilutions;

    Or is there something about the particular balance of the D76 formula that makes it suitable for higher dilutions that makes dilution inappropriate for (say) Adox Borax MQ ?
     
  2. clayne

    clayne Member

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    No, nothing specific about D-76 that lends itself to that. Most typical developers are some combination of MQ, HQ, sodium sulphite, carbonate, bromide, etc.
     
  3. Gerald C Koch

    Gerald C Koch Member

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    With dilutions greater than 1+1 you run the risk of not having enough developing agents to properly develop film unless an excess of developer is used. That is more developer is required than just to cover the film.

    The various formulations are designed for use in replenished systems where a good buffering system is required. They are of no particular advantage when D-76 is used as a one-shot.

    A concentration of sulfite of approximately 80 g/l exhibits the greatest amount of silver halide solvent action. Therefore if you mix your own then it is advantages to reduce the sodium sulfite content to 80 g/l when D-76 is used FS.
     
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  4. Ian Grant

    Ian Grant Subscriber

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    1+3 does have that effect if you don't use excess developer (volume) and some of us compromise by using developers like ID-11/D76, Xtol or Perceptol at 1+2, I've never understood why manufactuers don't list times for this dilution. I started using ID-11 at 1+2 at therequest of a photographer who asked me to process his films and was surpised at the quality of the results, quite close to those from replenished developer


    I agree on the 80g/litre Sulphite it's remarkable that Adox Borax MQ results in slightly finer grain, less speed loss, better sharpnes and excellent tonality, Agfa 44/Agfa Ansco 17 are very similar.

    While I much prefer replenishment with all these developers, I always use 1+2 if I need to use one shot.

    Ian
     
  5. pdeeh

    pdeeh Member

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    I think the point about having sufficient developing agent(s) was probably what was nagging at me and made me post the question. I'm mindful of this concern, having had a play with 1:80-1:100 Rodinal developing.

    Earlier today I noticed a Flickr user giving a formula for "Eastman Borax developer" which he suggested should be used 1:1. As his formula seemed to be that of Adox Borax MQ but with only 1g Metol/l (I think that's a common error from an older version of one of the "cookbooks"?) I started to wonder about the impact of dilution on top of such an error, and then about dilution more generally.

    Buffering (how it works and why it is needed) is one of the dark mysteries for those of us without much of a clue about chemistry, but point taken Gerald.

    The issue of diluting & using one-shot (as opposed to replenishing) prompts me to wonder if D76 et al were designed with such dilutions in mind , or whether this was purely empirical and a result of end-users experimenting.
     
  6. Ian Grant

    Ian Grant Subscriber

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    The Eastman Borax MQ developer is D76 although there was an earlier Eastman Kodak Research formula published before D76 for still photography and that was used more dilute, this is the developer Haist reffered an author to.

    D76 was designed for use Full strenght and replenished and it waas many years before dilution was recommended. Commercial D76 now has greater buffering which is beneficial when used dilute giving greater pH stability.

    Ian
     
  7. David Lyga

    David Lyga Subscriber

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    Honestly, you have 'my' permission to dilute 1 + 4. Add a couple of grams per liter of sodium carbonate to the working solution. Test.

    You just might be surprised with your newfound and positive attempt at frugality. I have had no problems, no 'shortage' of developer activity. Do clip tests until you determine how much (and at what temperature) to develop your film. - David Lyga
     
  8. pdeeh

    pdeeh Member

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    What a bizarre response
     
  9. Peltigera

    Peltigera Member

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    I use ID11 and D76 at a dilution of 1 + 3 and have experienced no problems at all. Ilford give 1 + 3 as an 'official' dilution with no warnings .
     
  10. Ian Grant

    Ian Grant Subscriber

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    A lot depends on the volume of developer and in practice some people probably wouldn't notice a difference, it might suit their photograohy. Howevere there is a subtle difference particulary in the highlights where developer becomes exhausted and that leads to a flattening of the tonal range, the term that used to be used was compression. A lot then depends on the lighting conditions if it's contrasty lighting then it might be OK but personally I find 1+3 leads to dull lifeless negatives for my way of working.

    Ian
     
  11. TheToadMen

    TheToadMen Subscriber

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  12. David Lyga

    David Lyga Subscriber

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    Ian, to be honest and complete I did mean continuous agitation in order to to mitigate potential deleterious effects of 'running out of steam' as far as developer activity is concerned. I should have said that upfront. - David Lyga