E-6 Reality Check on Wikipedia

Discussion in 'Color: Film, Paper, and Chemistry' started by Discpad, Aug 20, 2007.

  1. Discpad

    Discpad Member

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    Hi gang!

    I've been massaging the E-6 Process article on Wikipedia, and I'd like to get some feedback for both accuracy as well as clarity.

    My goal is to build an accurate reference so when questions arise here on APUG, we can refer people to the article.

    Please, post your comments here in this thread so we can discuss them, and then I'll add them in as appropriate. One of the problems with Wikipedia in general is the basic concept of anonymous edits; but if one person handles the actual entries, clean, concise and accurate articles is the end result.

    Cheers!
    Dan Schwartz

    [Note 1: I had to re-subscribe because the server lost my login info.]
    [Note 2: I also posted this on Photo.Net, where I usually hang out.]
     
  2. Photo Engineer

    Photo Engineer Subscriber

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    Dan;

    Comments follow:

    1. The stannous chloride in the reversal bath fogs the emulsion instantly.
    2. The color developer contains no hydroquinone. Sorry.
    3. The prebleach contains no formalin.

    Hope this helps for initial comments.

    PE
     
    Last edited by a moderator: Aug 20, 2007
  3. Photo Engineer

    Photo Engineer Subscriber

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    More comments:

    1. A Ferricyanide bleach will cause excessive dmin in the film without a clearing bath and may hurt the image. E6 films were designed to go through a Ferric EDTA bleach.

    2. A Sodium Thiosulfate fix will not be strong enough for E6 films without using very long fix times.

    3. You list more than 3 baths for a so called 3 bath process.

    PE
     
  4. Discpad

    Discpad Member

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    Ron, I didn't do the 3 bath process: I simply inherited it and left it alone.

    But, I sure as hell will update it with your suggestions!
     
  5. Discpad

    Discpad Member

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    Ron:

    1) I need to research the reversal bath action a bit more: It's very late and my fiancee wants me to go to bed! :D

    2) Nowhere does the article list hydroquinone as an ingredient of the color developer (nor should it!): Try a word search;

    3) The MSDS for E-K prebleach lists formalin as an ingredient. Perhaps you were thinking of the older conditioner, which required formaldehyde in the stabilizer bath?
     
  6. Discpad

    Discpad Member

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    Do you know if the Tetenal 3 bath kit uses a ferric EDTA bleach(-fix)?
     
  7. Photo Engineer

    Photo Engineer Subscriber

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    Sorry Dan. I meant first developer. My error. The first developer does not contain HQ. It is a no-no. Crossover, bad color, bad grain, bad sharpness etc..... Whatever. HQ is not used in the first developer. Also, AFAIK, an ingredient is missing now that I look it over again.

    My bottle of prebleach does not list formalin. It lists a proprietary thiol which is an R-SH containing organic compound.

    IDK what Tetenal uses. I only know that use of ferricyanide after a color developer without a clear will cause a pink dmin due to the oxidation of color developer. You have to use a clearing bath to neutralize the color developer and bring the pH down to a safe level.

    PE
     
  8. patrickjames

    patrickjames Member

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    Why don't you post it here instead? Seems like a huge waste of time to do it there when some schmuck can change it, or at least that is what I understand about Wikipedia. I never use it for this reason. Seems there are many things that are inaccurate and manipulated from what I have read.

    Patrick
     
  9. srs5694

    srs5694 Member

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    Concerning the DIY formulas, they seem to originate (or at least are also reported) here. In fact, this is the only DIY E-6 formula I've ever encountered on the Web. I mention this mainly so you can add a reference. PE has commented on this formula's deficiencies here on APUG in the past.
     
  10. Discpad

    Discpad Member

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    Yeah, I've seen the Watkins formula in the past... And it's not even a 3 step, as it was listed when I inherited the page (and I left that way).
     
  11. Discpad

    Discpad Member

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    Re-worked the page

    OK gang, based on the great suggestions so far, I reworked the sections on the page containing the Watkins chrome brew formula; and also moved the three step process hack to the bottom of the page.

    PE: I need to dig up the MSDS for the first dev, yada yada yada. As I remember it, I mentioned over on Photo.Net that it was a(n) MQ developer, you corrected me, and I looked it up.

    Thanks for the help!
     
  12. Photo Engineer

    Photo Engineer Subscriber

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    Dan;

    The first developer is a High Acutance developer with 2 developing agents and an additional ingredient not commonly listed. The developer is slow acting and very stable. It develops the many layers in E6 films just perfectly to prevent crossover and gives good dmin and dmax in both silver and dye. The developer you list can go awry. It is a very old formula which was corrected in Darkroom Techniques in the 90s. That formula, I think by Dignan, was the most correct I've seen.

    If you use a ferricyanide bleach, you must use a sulfite - acetic acid stop bath after the color developer and a good long wash to remove any color developer and acidify the film. This is called the clearing bath.

    My E6 bleach contains Ferric Nitrate IIRC. You might want to look this up as well.

    The pre-bleach also contains acetic acid and EDTA according to the MSDS.

    The stabilzer, final rinse is a proprietary chemical as well.

    PE
     
  13. Discpad

    Discpad Member

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    The developer I list? Do you mean the Watkins developer?

    I'm coming very close to wiping out the entire home-brew section of the article, anyway.
     
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  15. dmr

    dmr Member

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    Please leave it in, even with a disclaimer that it may not be ideal.

    I read the article and the ingredients and such were quite interesting, even though I'm not a photo chemist by any means.

    Thanks for putting this in there.

    About the only thing I would like to see in there is a bit more on how the "magic" of the CD3 works. Not as detailed as chemical equations and such, just some narrative on how the dye forming works. :smile:
     
  16. Photo Engineer

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    Dan;

    The real E6 first developer is what I describe, not yours. Yours is incorrect.

    Yours will be a good developer, but not for all E6 films and not for all characteristics due to the lack of one correct developing agent and an added ingredient for image structure.

    AFAIK, the correct formula was published one time by Pat Dignan in Darkroom Techniques in the 90s.

    PE
     
  17. Nick Zentena

    Nick Zentena Member

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    The BJP annual I have has different formulas. No idea if they're better/worse then the Watkins.
     
  18. Discpad

    Discpad Member

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    Could you please post them here for comment?
     
  19. Nick Zentena

    Nick Zentena Member

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    First Developer pH 9.6 +/-0.1

    Calgon 2grams
    Sodium sulphite anhydrous 15g
    Potassium hydroquinone monosulphate pure 15g
    Diethylene glycol 20g
    Potassium carbonate anhydrous 15g
    Phenidone 0.4 g
    Sodium thiocyanate 20% solution 8ml
    Potassium bromide 1.8 grams
    Potassium iodide 1% solution 4ml
    water to 1litre

    I think the alternate is the Watkins
     
  20. Nick Zentena

    Nick Zentena Member

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    Reversal bath pH 5.8 +/- 0.1

    Propionic acid 12ml
    Stannous chloride 1.65 g
    p-Aminophenol 0.5 g
    Sodium hydroxide 4.8 g
    BDH calcium complexing agent #4 15ml
    water to 1litre
     
  21. Nick Zentena

    Nick Zentena Member

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    Conditioning bath pH6.1

    Sodium sulphite anhydrous 10g
    EDTA Acid 8 g
    Thioglycerol 0.5ml
    water to 1litre
     
  22. Nick Zentena

    Nick Zentena Member

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    Bleach pH 5.5-5.7
    Potassium nitrate crystalline 30 g
    Potassium bromide 110g
    EDTA NaFe or NH2Fe Merck 110g
    water to 1litre
    Note teh nitrate is optional to protect stainless tanks
     
  23. Nick Zentena

    Nick Zentena Member

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    Stabiliser
    wetting agent 5.ml [Aerosol OT,anionic or any similar product 10% solution]
    Formaldehyde 35-40% 6.ml
    water to 1litre
     
  24. Nick Zentena

    Nick Zentena Member

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    I left out the colour developer and fixer since it seems they haven't generated much discussion.
     
  25. Discpad

    Discpad Member

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    Looks like the active agents are phenidone and hydroquinone...

    What sayeth PE?
     
  26. Discpad

    Discpad Member

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    I guess this is the old conditioner, instead of the newer pre-bleach -- Especially since the stabilizer you list has formaldehyde.