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  1. #11
    desertrat's Avatar
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    Sodium sulfite also acts as an oxygen scavenger to protect the metol from oxidation. If you mix a metol only developer with borax and no sulfite, it will go bad very quickly. That's why formulas with metol recommend dissolving a pinch of sulfite first before adding the metol.
    Happiness is a load of bulk chemicals, a handful of recipes, a brick of film and a box of paper. - desertrat

  2. #12
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    Hi Gerald

    I need some advice... I currently use dektol and Ilford multigrade mixture for my lambda prints... 6litres of dektol stock and 5 litres of multigrade with 40 litres of water at 70 degree.
    I use this for lambda fibre prints and my 21 step wedge calibration is based on this rather strong dilution and a 3 minute 40 second dev time.

    I want to switch to my Solaral developer which is a metol, sodium sulfite, sodium carbonate and sodium bromide concotion, listed in the paper by William Jolly.
    What I hope to get is a 21 step wedge to match my current mixture.

    If I need more speed or more concentration do you have any recomondations?
    I cannot run the laser printer without getting a good calibration but I have never tried a non hydroqoninne developer for this . My goal of course is to make solarizations
    using the laser printer, which opens a lot of doors for me.

    thanks
    Bob


    Quote Originally Posted by Gerald C Koch View Post
    NO!

    Thee role of sulfite in a developer is a very complex one.

    While the sulfite content of a developer can be reduced it cannot be eliminated entirely. There are several reasons for this. Metol is a hydrochloride salt and is acidic. Enough base must be added to a developer to neutralize any acid from the metol. In many formulas the sulfite acts as the only base to raise the pH so that the metol can develop. Secondly without any sulfite a developer will likely produce stains on the negatives. I would suggest looking at the Crawley FX-1 formula for an idea of a minimalist sulfite developer. Thirdly, some sulfite must be present or film speed will suffer. Sulfite acts as a silver halide solvent and thus exposes active sites to the developing agent. There are more reasons which will not be discussed here.

  3. #13

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    While I have seen examples of solarization and read Jolly's article I have never tried the process. Have you read the following http://unblinkingeye.com/Articles/So...on/S2/s2.html?
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

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  4. #14
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    Quote Originally Posted by pierods View Post
    What would happen if one omitted Sodium Sulfite from d-23?

    Meaning:

    Distilled Water (125 degrees F) . . . . . . . 750 ml
    Metol . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 g
    ̶S̶o̶d̶i̶u̶m̶ ̶S̶u̶l̶f̶i̶t̶e̶ ̶(̶A̶n̶h̶y̶d̶r̶o̶u̶s̶)̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶1̶0̶0̶ ̶g̶
    Cold Water to make . . . . . . . . . . . . . . . . . . 1 ltr


    As far as I understand, SS is only used as a preservative, so I suppose that the only changes would be:

    - less fine grain
    - it should be used one-shot
    - one should mix it every time

    Would it work under these conditions?
    I'm a little curious about why you want to do this, Sulfite allergy?

  5. #15
    Rudeofus's Avatar
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    Quote Originally Posted by pierods View Post
    Excellent. How much?
    You seem to enjoy photochemistry and home brewing but lack the basics to formulate a developer. Learning is always a good thing and I recommend you dig through some photographic literature. Here is my recommended reading list:

    • Recipe selection on APUG and digitaltruth for a brief overview of common formulas. Don't get carried away with these recipes, quite a few of them are outdated and won't work as advertised with new film stock.
    • Mees, The Theory of the Photographic Process. This book is very old (think Forties) but very informative, and best of all, you can download it legally and for free.
    • Haist, Modern Photographic Processing. Despite its much newer date of publication, it offers quite outdated info on many subjects. Kodak would have stomped heavily on Haist's toes if he would have published more recent discoveries it seems. Still, B&W processing hasn't made all that much progress in the last 50 years, so his book is (IMHO) a very valuable and accessible resource. Although its main focus is B&W processing, it delivers the best explanation of color processes I have seen so far.
    • Anchell&Troop, The Film Developing Cookbook: a very short and concise resource, and the only book which looks at fairly modern recipes, including Crawley's formulas and necessary modifications to make a dev work well with T-Grain emulsions. Also the only book which describes Phenidone's properties compared to Metol.
    • Anchell, The Darkroom Cookbook: a much larger volume than the Film Developing Cookbook, mostly a big recipe collection.


    If you have a very tight budget, get at least the free book from Mees and Anchell&Troop's Film Developing Cookbook.
    Trying to be the best of whatever I am, even if what I am is no good.

  6. #16
    Bob Carnie's Avatar
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    i have done thousands with the formula he publishes, I am trying now to match developer speeds to make a calibration. does my last post make sense, as I may not be explaining myself properly.
    Quote Originally Posted by Gerald C Koch View Post
    While I have seen examples of solarization and read Jolly's article I have never tried the process. Have you read the following http://unblinkingeye.com/Articles/So...on/S2/s2.html?

  7. #17

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    LFA Mason,Photographic Processing Chemistry,p78:
    "Oxidised Metol combines with sulphite .....giving a monosulphonate of Metol.This reaction is an essential one in developers in which Metol is the sole developing agent, as certain oxidation products of Metol exhibit a strong inhibiting effect on development."

  8. #18
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    Quote Originally Posted by desertrat View Post
    Sodium sulfite also acts as an oxygen scavenger to protect the metol from oxidation. If you mix a metol only developer with borax and no sulfite, it will go bad very quickly. That's why formulas with metol recommend dissolving a pinch of sulfite first before adding the metol.
    Thanks for replying - but if I don't need my developer to keep (i.e. I mix it when I need it), does that work - no SS and borax ?

  9. #19
    pierods's Avatar
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    Quote Originally Posted by eclarke View Post
    I'm a little curious about why you want to do this, Sulfite allergy?
    Hi - I want to try because I like to experiment!

  10. #20

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    As stated above, sulfite has a complex functionality in developers, especially in metol based developers. In D-23 it acts as a silver solvent, preservative, and alkali to raise the pH to a point where metol will work. Just eliminating it will not work. Gainer did a number of experiments with eliminating sulfite from developers. They are almost all documented in the APUG archive. He used ascorbate as a combination developing agent and preservative (anti-oxident in this case). They all required a fairly strong alkali to make them work. Most of these developers were not terribly successful, although they were interesting.

    Sulfite-free developers from Patrick Gainer
    Original

    Sodium carbonate 1 tsp
    Ascorbic acid 1/2 tsp
    Metol 1/16 tsp
    WTM 1 qt

    2.5 ml of a phenidone solution (1/4 tsp (0.65 g) in 80 ml of denatured alcohol) may be substituted for the metol.

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