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Article: EZ Rodinal

  1. #1
    gainer's Avatar
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    EZ Rodinal

    EZ Rodinal

    To 400 ml water, add:
    85 g anhydrous sodium sulfite.
    40 g p-aminophenol base.
    Stir well. Add
    13.8 g sodium hydroxide or 19.2 g potassium hydroxide.
    Add water to make 500 ml.
    No matter how you stir, there will be some precipitate of p-aminophenol. Don't filter it out. The theory is that as p-amonophenolate is oxidized by air, the hydroxide is formed which combines with some of the precipitate to form more phenolate.

    With the chemicals we can buy from Photographer's Formulary and other current sources, there is no need for the titration to leave "just a few" crystals undesolved. All the weighing and mixing can be done in a few minutes. Using the p-aminophenol base instead of the hydrochloride, and the sulfite instead of the bisulfite cuts down the amount of hydroxide needed. The net result is the same except for lack of an amount of a chloride. If you think it is necessary, you can add an amount of canning salt (non-iodized) equal to about 1/2 the weight of p-aminophenol. I can tell you it never will be missed if you leave it out.

    PF can sell potassium hydroxide without the special forms etc.
    Gadget Gainer

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    noseoil's Avatar
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    Same dilutions as with "store bought" Rodinal and activity level the same? Thanks, tim

  3. #3
    gainer's Avatar
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    Quote Originally Posted by noseoil View Post
    Same dilutions as with "store bought" Rodinal and activity level the same? Thanks, tim
    Yep. I tried it with the times listed on the side of an old Rodinal bottle with Agfa 100. At first I thought the negative was much too flat, but it printed very well on a VC RC paper without any filter, and also scanned very well. I had set the Elan IIe meter for ISO 125, a slight underexposure, and photographed the edge of a deep woods with plenty of highlight and shadow.
    Gadget Gainer

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    Bruce Osgood's Avatar
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    I tried this formula with Pan F+ at box speed and 6 minutes as per MDC and got what I feel are identical results to Agfa's Rodinal.

    EZ Rodinal has become my developer of choice for traditional films shot under 100 EI. I will be trying it on T-grain film soon, I hope it works as well.

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    Hello Gainer,

    Sorry to bring such an old topic.
    I'd like to know how are the keeping qualities of your EZ Rodinal. Does it last at least a year?

    Regards,
    Guilherme

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    Hi Guilherme,


    I've been doing this for the last year. And to be honest, if you make small batches of 250 ml (30 Paracetamol tablets 1000mg, 20gr NaOH and 50gr Sodium Sulphite) you'll most probably use it before it get bad. And when (or if) it gets bad, being so easy and cheap.. just make another batch.

    In my case, I had a batch that lasted at least 6 months, without any "special" protection (the last solution was on an almost empty bottle, and worked the same.. to me).

    It's fun.. enjoy!

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    Quote Originally Posted by amouco View Post
    And to be honest, if you make small batches of 250 ml (30 Paracetamol tablets 1000mg, 20gr NaOH and 50gr Sodium Sulphite) you'll most probably use it before it get bad.
    A true Rodinal-like developer cannot be made using both sodium sulphite and sodium hydroxide. Either the one or the other, or both, needs to be potassium. With all-sodium chemistry, you will only get 80% of the total solubility required, and the developer will be prone to early failure. If you use potassium hydroxide, it is possible to make a full-strength developer with zero precipitate forming, and which lasts as long (practically forever) as Rodinal. Check my post history for a calculator in Excel that will calculate the quantities for any combination of paracetamol, p-aminophenol, sodium/potassium sulphite or metabisulphite, and sodium/potassium hydroxide. My oldest batch is now 3 years, with no sign at all of deteriorating.



 

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