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  1. #1

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    Ascorbate paper developer

    After great success with a phenidone/ascorbic acid film developers based on Patrick Gainer's formulas, I've been wanting to make paper developer with the same chemicals. However, I've had no luck.

    Here's one of my first tries:

    1.5 liters of distilled water
    1 tbsp sodium ascorbate (NOW Foods)
    20 ml phenidone in rubbing alkocol as per Gainer on unblinkingeye
    3 tbsp sodium carbonate, anhydrous
    3/4 tsp bromide (for contrast)

    This worked OK, except that the maximum black achieved was weak. Longer development did not help. Also, it exhausted quickly, giving even weaker blacks. The rapid change in color to pink, whether I used it or not, hinted that aerial oxidation might be the problem.

    The formula is similar to Chris Patton's E-72, which also contains sulfite. I tried adding sulifte to no avail.

    After a while, I realized that if I removed the phenidone, the bromide became unnecessary. The contrast acheived by just ascorbate and carbonate was a close match to Agfa Neutol, and gave a pleasing warm tone.

    Secondly, I found that if I exchanged the carbonate for sodium hydroxide, the maximum black improved. I'm a bit leery of this - I'd rather use carbonate than hydroxide for safety reasons.

    Now I have:
    1 L water
    1 tbsp ascorbate
    2 tbsp sodium hydroxide (Red Devil Lye)

    (if you mix this, add the lye to the water, not the other way around)

    The contrast and D-max now both match Neutol, but it still turns pink and dies in less than an hour. I've tried adding Calgon to no avail. I tried added Phisoderm, which is 2 percent salicylic acid, but that ruined the D-max.

    Any clues?

  2. #2

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    Take a look at the Ascorbic Acid paper formulas in the APUG Chemistry section.

    Comments:
    Sodium Sulfite has no effect on the activity of either Phenidone or Ascorbic Acid.

    Try adding more phenidone. BTW, phenidone goes off fairly quickly in alcohol so dissolve it just before you use it. Don't try to keep a stock solution in alcohol. Stock solutions dissolved in polyethylene glycol or TEA will keep for a very long time.

    Calgon is a water softener - it has no effect on developer activity and is not a preservative. Try adding phenidone and/or ascorbic acid. The ascorbic acid acts as a developer and a developer preservative. It is difficult to add too much phenidone, however, too little phenidone will cause some of the symptoms you describe.

    Bromide is a restrainer - it reduces developer activity. Start with no bromide and then add small amounts of bromide as a percentage solution - if needed. Benzotriazole should have a stronger effect with phenidone.
    Tom Hoskinson
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  3. #3

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    Quote Originally Posted by Tom Hoskinson
    Sodium Sulfite has no effect on the activity of either Phenidone or Ascorbic Acid.
    It does in film developers. But I was adding it hoping for an antioxidant effect, and that was a bust.

    Quote Originally Posted by Tom Hoskinson
    Try adding more phenidone. BTW, phenidone goes off fairly quickly in alcohol so dissolve it just before you use it. Don't try to keep a stock solution in alcohol. Stock solutions dissolved in polyethylene glycol or TEA will keep for a very long time.
    I tried using this:
    1l water
    60 ml PG with phenidone and ascorbic acid as per Gainer
    1/2 tsp bromide

    It had less than maximum D-max and died quickly. I've tried PC-TEA too. In my experience more phenidone mainly affects the lighter values of the print, giving low contrast. So I had to add bromide to clear up the highlights and get the contrast to match commercial developers.

    Quote Originally Posted by Tom Hoskinson
    Calgon is a water softener - it has no effect on developer activity and is not a preservative.
    Yeah, the Calgon was a long shot. I tried it because I note it's found in Dektol.

  4. #4

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    Quote Originally Posted by psvensson
    It does in film developers. But I was adding it hoping for an antioxidant effect, and that was a bust.
    Dektol.
    The ascorbic acid acts as the antioxidant/preservative, so sulfite is not needed in that role.

    In both film developers and paper developers that use a combination of Ascorbic Acid and Phenidone and no other developing agents, sodium sulfite has no effect on the rate of development. See Grant Haist's Modern Photographic Processing, Volume 1, Table 1, page 224.

    If Metol replaces the Phenidone in the mix, then sodium sulfite increases the rate of development.
    Tom Hoskinson
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  5. #5
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    Quote Originally Posted by psvensson
    It does in film developers. But I was adding it hoping for an antioxidant effect, and that was a bust.



    I tried using this:
    1l water
    60 ml PG with phenidone and ascorbic acid as per Gainer
    1/2 tsp bromide

    It had less than maximum D-max and died quickly. I've tried PC-TEA too. In my experience more phenidone mainly affects the lighter values of the print, giving low contrast. So I had to add bromide to clear up the highlights and get the contrast to match commercial developers.



    Yeah, the Calgon was a long shot. I tried it because I note it's found in Dektol.
    Did you really leave out the alkali, or was that slip of the keys?

    I have found that the ascorbate powders do not keep as well as ascorbic acid. By the way, erythorbic acid, AKA isoascorbic acid, is cheaper at www.Kicgroup.com than the vitamin C.

    Ascorbic acid and phenidone are superadditive in ratios up to 80:1. The curve relating activity to concentration looks like a curve of contrast vs developing time, levelling off at the higher ratios. The best preservative for ascorbate is more ascorbate. It does not form a sulfonate with any sulfite as do hydroquinone and metol. You may in fact preserve the sulfite with the ascorbate. Excess ascorbate is a better way to go with paper than excess phenidone.

    I have left PC paper developer in the tray overnight with little or no loss of activity, though I usually mix it fresh for each session. Tom's suggestion about using a glycol as solvent for the phenidone is good. You can use ordinary glycerine as well if you don't mind the extra viscosity. Propylene glycol is a double alcohol, so to speak, and glycerine is the triple. I seem to recall that one is 1,2 propanediol and the other is 1,2,3 propanetriol. Anyway, you can try it out quickly by using glycerine, although drugstore prices for small amounts are greater.

    I generally use sodium carbonate as alkali, but if I use my tap water, I get a lot of calcium and magnesium precipitate. It's good for the heart, but a nuisance in developer. I use a mixture of 20 Mule Team borax and Red Devil lye with tap water. The ratio is about 1 tsp lye to 1 tbs borax for a liter of working solution. This goes along with a tbs of ascorbic or erythorbic acid and 15 ml of 1% phenidone solution.
    Gadget Gainer

  6. #6

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    Quote Originally Posted by Tom Hoskinson
    In both film developers and paper developers that use a combination of Ascorbic Acid and Phenidone and no other developing agents, sodium sulfite has no effect on the rate of development. See Grant Haist's Modern Photographic Processing, Volume 1, Table 1, page 224.
    In my experience with E-76-type developers, sulfite concentration has a very strong effect on activity.

  7. #7

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    Quote Originally Posted by gainer
    Did you really leave out the alkali, or was that slip of the keys?
    Ooops. I did use 2 tbsps carbonate.

    Quote Originally Posted by gainer
    I have found that the ascorbate powders do not keep as well as ascorbic acid.
    That's interesting. Does ascorbate age faster in solid form or in solution? I guess they ionize the same way in an alkaline solution, so the intuitive answer would be "solid form," but not everything about photo chemistry is intuitive, it seems.

    Does your developer turn pink too? I have used AA as well, but maybe only in the PG and TEA mixtures. Maybe it's worth trying on its own.

    Quote Originally Posted by gainer
    The best preservative for ascorbate is more ascorbate. It does not form a sulfonate with any sulfite as do hydroquinone and metol. You may in fact preserve the sulfite with the ascorbate. Excess ascorbate is a better way to go with paper than excess phenidone.
    I tried adding more ascorbate, and that did seem to extend life, but only up to a point. And it didn't solve d-max problem.

    Quote Originally Posted by gainer
    I have left PC paper developer in the tray overnight with little or no loss of activity, though I usually mix it fresh for each session.
    It's very strange that results can differ so much!

  8. #8

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    Quote Originally Posted by gainer
    I use a mixture of 20 Mule Team borax and Red Devil lye with tap water. The ratio is about 1 tsp lye to 1 tbs borax for a liter of working solution.
    That approximates metaborate, right? I've tried metaborate as the alkali too, but it didn't give a full D-max.

  9. #9

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    Sodium Ascorbate

    I would like to try adding Sodium Ascorbate to Rodinal.
    Does this masquerade in the supermarket under some common name or does it have to come from a chemical supplier?
    Mark
    Mark Layne
    Nova Scotia
    and Barbados

  10. #10

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    On face a contradiction. What do you suppose could be the reason for that.
    I'd suggest test conditions. Youself and G. Haist might agree with one another
    after testing with the same methods and conditions. You results though may
    be the better news.

    Have you tested at constant ph? Dan

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