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  1. #1
    Ian Grant's Avatar
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    Modern Rodinal Substitutes Part II

    Apologies for having to start a new thread but I can't read or even access the first to reply to posts.

    So with a bit of telepathy

    Quote Originally Posted by Kirk Keyes View Post
    Well, there's a problem there, as it's really hard to measure pH accurately when it gets much above 12.5 or so. You have to start getting special electrodes and the like.

    But for MSDS work, it doesn't have to be too precise.
    __________________
    Kirk

    A point that's being missed is that A&O give a figure of 2.7% Potassium Hydroxide not 3% in older Agfa MSDS.

    The pH is around 14 sure, but the actual requirement is the pH of the working dilute solution rather than the concentrate which is given elsewhere as pH 11.55, which I commented on in the first post of the thread.

    Way back Ron (PE) mentioned adjustments to Rodinal before bottling, the question we need to ask is are they adjusting on the basis of the concentrate, or also doing some tests on a dilute sample, as this will be a far more accurate indicator.

    Can someone please post a link to this continuation on the original post.

    Ian

  2. #51
    Ian Grant's Avatar
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    The big problem with both the Ilford & Kodak charts is they don't take into account dilution of ID-11/D76 or Perceptol/Microdol-X where the developers begin to behave quite differently at 1+3.

    Ian

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    Quote Originally Posted by Ian Grant View Post
    The big problem with both the Ilford & Kodak charts is they don't take into account dilution of ID-11/D76 or Perceptol/Microdol-X where the developers begin to behave quite differently at 1+3.

    Ian
    Ilford do cite ID-11 diluted 1+3 as yielding the highest sharpness while Perceptol and Microdol-X also provide good performance at the same dilution.
    I have tried all of those developers and I can`t see much, if any difference in grain between D-76/ID-11 1+3 and the extra fine-grain developers 1+3, although it might show with huge magnifications.
    I find that D-76/ID-11 tends to compress the tonal range when diluted 1+3 while Perceptol and Microdol-X provides more sparkle at 1+3 with good sharpness. I use 1+1 with D-76, although I have not tried it 1+2 yet.
    BTW, have you read the United States Patent Office number 3,161,513 (Patented Dec, 15, 1964)? Photographic developer compositions containing an antistain agent?

    Good luck with your quest for a Rodinal substitute.

  4. #53
    Ian Grant's Avatar
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    Yes, I've got that Patent amongst a heap of others. Example 4 & 6 are a very slight re-working of the Wellington & Ward Borax MQ developer and a side step in the evolution of D76

    Ian

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    Photo Engineer's Avatar
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    Quote Originally Posted by Ray Rogers View Post
    What films do these data apply to, most strictly, in your knowledge/opinion?

    (How were these charts actually constructed?
    The developers are mentioned, but on what films?
    Was there any "weighting" of the results that you know of? (80% modern 20%traditonal... or some such? )

    BTW
    What developers/dev. agents do you know to be better?
    Ray;

    I know nothing about the data behind the chart nor its method of construction. I can infer how it was done, but that is just inference.

    I can say that Dimezone-S is far better than Phenidone as an example of better all round developing agents.

    PE

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    Photo Engineer's Avatar
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    Quote Originally Posted by Ian Grant View Post
    Yes, I've got that Patent amongst a heap of others. Example 4 & 6 are a very slight re-working of the Wellington & Ward Borax MQ developer and a side step in the evolution of D76

    Ian
    This is the seminal "Anti Dichroic Fog" patent among other claims hidden in it. It was one of Henn's major works and is cited by A&T in the FDC. This is not the answer to the real problem, nor does it correctly give the "secret" ingredient of Microdol X, which is also used elsewhere from what I understand.

    PE

  7. #56
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    Quote Originally Posted by Ian Grant View Post
    Would you buy it as R09 from Calbe and sell it as Gainerol

    There's an interesting cemical called "Oxygen Scavenger" which is sold by a bulk photographic chemical supplier.

    I've never seen it in any published formulae but it's sold in liquid form in sizes up to 1000 litre IBC's - Ammonium Bisulphite

    Ian
    You would not want to put Ammonium Bisulfite into a developer! It is great in fixers though.

    PE

  8. #57
    Ian Grant's Avatar
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    Quote Originally Posted by Photo Engineer View Post
    Ray;

    I can say that Dimezone-S is far better than Phenidone as an example of better all round developing agents.

    PE
    But then there's the original Phenidone and then Phenidone Z and various other derivatives.

    Many companies have used commercial "Phenidone" - Ilford, May & Baker (Champion), Agfa, Orwo (Calbe), Paterson, Forte, Foton, Foma, Fotospeed and a whole host of smaller companies. Between them they have all produced a wide and varied range of excellent developers using Phenidone in combination with one or more additional developing agent.

    Dimezone-S isn't an "all round" developing agent, nor is Phenidone, because unlike Metol, p-Aminophenol, Pyrocatechin, Hydroquinone etc they are not practical as sole developing agents except in very limited uses.

    I don't know what form my original Ilford Phenidone was I'd guess Phenidone Z, I only finished it a couple of years ago, the date stamp was 1962, it has exceptionally good keeping properties

    Ian

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    Ian;

    I was comparing two developers with very similar structures under identical conditions in my thinking. Phenidone and Dimezone-S are basically cyclic hydrazine derivatives. In alkali, the Phenidone ring opens and becomes inactive much more rapidly than Dimezone-S and the activity is somewhat lower. For this reason, Kodak used Dimezone-S in the PR-10 pods due to the high alkali content and the need for quick development.

    So, for a quick OTOMH answer, those are two to compare, and if you do, (and which I have done), the Dimezone-S comes out ahead.

    PE

  10. #59

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    Quote Originally Posted by Photo Engineer View Post
    You would not want to put Ammonium Bisulfite into a developer!
    It might get a little stinky...
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  11. #60
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    Would potassium metabisulfite be less likely to be oxidized to a sulfate than potassium sulfite? Some extra KOH would be needed, but the combination might be less expensive to the hobbyist who makes relatively small batches. Or, can one of you tell me a source of relatively small amounts of the liquid concentrate?
    I have what I believe to be an excellent Metol analog of Rodinal, but have only been able to test the sodium sulfite version. Even so, it seems to be capable of greater SBR and better shadow detail than any of the many Rodinal expedients I have tried.
    The attachments are from scans of a 10X print of a 35 mm EDU 400 Ultra neg. That puts the detail at about 30X, enough for a 30"x45" print from the full width of the negative. The viewing distance for such a print for proper perspective would be about 54" (no grain sniffing allowed).
    Attached Thumbnails Attached Thumbnails New Metolal test 1 Detail.jpg   METOLAL2 TEST1.jpg  
    Last edited by gainer; 09-01-2009 at 12:33 AM. Click to view previous post history. Reason: Change attachment
    Gadget Gainer



 

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