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  1. #21
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    SkipA, the formulas that I have are rather old and spotty but here goes.

    The developer is a low alkali phenidone hydroquinone developer. That is all the information that I have. It is also indended to develop as much silver as possible without excessive fog.

    The dye bleach is sodium bromide, about 5 g/l; sulfamic acid or sulfuric acid in a quantity sufficient to get to a pH of about 1.0 (This would range from about 20 - 100 g/l depending on which acid you use), and to that you add 0.1 - 1 g /l of phenazine (a known carcinogen - since my formula Ilford has switched to a less toxic chemical - I believe that it is a quinoline but I cannot find any information about it).

    The fix is an acidic fix of about 4.5 with sulfite and sodium hypo. Kodak Rapid Liquid Fix or similar might be useful without the hardener.

    I cannot find the definitive formula list of the Ilford chemistry, just the sketchy outline above. Sorry I cannot do better.

    This information comes from a talk given by one of the Ilford engineers, and also some patent references in which they discuss bleach-fixes for dye bleach materials.

    PE

  2. #22
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    Sorry, but the fix is pH about 6.5 not 4.5.

    PE

  3. #23
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    I've read several times that one can (for instance) use the Beers paper developer system to control Ilfochrome contrast; as you suggest, Kodak or other rapid fixer works fine for fixer; it's only the bleach that's really critical. Sodium bromide isn't impossible to get, and sulfuric acid is both not hard to get and used in other photo formulae (like reversal bleaches). The one that might be tricky is the phenazine or whatever has replaced it.

    All likely to be a moot question, of course, since if Ilfochrome chemisty is gone, the paper and tranny film won't be far behind.

    I was seeing Ilfochrome as a way I could make Polaroid-like one-off color prints or trannies in my plate cameras without having to deal with RA-4 materials and chemicals. OTOH, RA-4 can be reversed without much difficulty (develop in B&W paper developer, exposed to light to reverse, then apply standard RA-4 process); the main annoyance is it's likely to require significant filtration to make images direct from a scene, where I'm told Ilfochrome materials don't. Let's hope reports of Ilfochrome's demise have been greatly exaggerated...
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  4. #24
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    Donald
    I don't think that the ilfochrome(cibachrome) line will be discontinued in any short order. We are using Lambda technology to produce cibachromes and have found that we are using more and more material as time goes on.
    I do agree that with the shrinking E6 (transparancey) market, the traditional side of ilfochrome( cut sheet, CLM1k, CPS1K and CFK1k) will slowly phased out but roll 20 Inch and 30 inch (cibachrome universal ) will be seeing a massive increase with the lazer printers that are situated in labs throughout Europe and North America, I would also imagine Australia will be strong in this area as well.
    The inkjet market totally hit the cibachrome market and Ilford did nothing to fight back, but now with these new writers producing beautiful work it will not be long before a resurgence of ciba will occur.
    If you do not like glossy surface ciba is not for you , but there is no other product available that has a better colour gamut than cibachrome. I print most end products and can stand behind this statement.
    Ink jet is a pale comparison , as is crystal archive and endura RA4
    One only has to print from various files on each media to see this.

  5. #25

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    After using the P30 kits for a few years I've been playing around with my own developers in order to resolve the contrast issue. Results so far show promise. Firstly the developer is basically a normal B&W developer with a small amount of thiosulphate added to remove the masking layer. Personally I've been testing with the Beers formulas which for lower contrast uses only the metol developer, with the thiosulphate added at a rate of 0.1 to 0.2 grams per 100ml of developer (ie 30ml Beers A stock + 60ml water + 0.1 gm thiosulphate). This develops a silver image in the paper for each of the three layers. I can't see any reason why you couldn't use a normal multigrade type developer (with thiosulphate added) if you're happy with a normal contrast image. Dilution and time can be used to tweak things slightly. You can also use phenidone/ascorbic acid developers if you have a reaction to metol.

    For the bleach I've been using the P3 version which needs to run either longer or at a warmer temperature than the normal P30 bleach. The bleach removes the dye from the paper where there is metallic silver and at the same time converts the metallic silver back to a silver halide. Also although it requires a higher temperature or longer time and does deserve respect I prefer the P3 bleach as you can mix up enough for the job at hand. You do need to neutralise the bleach by adding sodium bicarbonate (or similar) before disposal. Ensure there's adequate ventilation.

    The fixer step is normal rapid fix at 1+9 dilution. This is a simplistic view of the process but it seems to work. The filtration values tend to require more cyan/magenta than the standard P30 chemicals however the ability to control contrast at the developer stage is a big bonus. Ilfochrome still suffers from slight colour crossover (cyan highlights, red shadows) with E6 films although it's not always noticeable and some films are more prone to the problem than others.

    Roger.

  6. #26
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    I have a list of about 5 substitutes for phenazine that can be used in dye bleach solutions if you wish. I don't know which one is used currently. I have searched for my old Ilford formulas, but cannot find them. I must have thrown them out.

    One caution is this. Low contrast black and white developers often do not give low contrast by lowering the amount of silver, they do it by changing the form of the silver image so that it appears low in contrast. However, dye bleach works on the quantity of silver formed not the way it appears to the human eye, so this can fool you when you are playing with low contrast developers.

    PE

  7. #27

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    Thanks PE, Roger, Bob, and Donald. I looked up the MSDS for quinoline and it is apparently a fairly hazardous chemical too. Maybe almost as bad as Phenazine. I'm careful with chemicals, but I still think I might be better off trying the P3 bleach with one of the modified developers that Roger mentioned.

    Bob, now I'm confused about the paper types. Which one should I use if I want a very bright and color saturated glossy image?

  8. #28
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    PE, I'd be very interested in the list of dye bleach candidate chemicals. From what I've read, if I can make the bleach myself (and I'm pretty sure I can if at least one of the chemicals is obtainable -- nothing in that bleach is likely to be any more hazardous than the dichromate used in C-41 bleach, which people use for lots of things pretty routinely and safely), I can cut the cost of processing the Ilfochrome enough to be worth obtaining and cutting the paper or display film. It'd be nice to be able to get it precut to 9x12 cm film size, of course, to fit my sheaths...
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  9. #29
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    Quote Originally Posted by ras351
    Firstly the developer is basically a normal B&W developer with a small amount of thiosulphate added to remove the masking layer.
    Given what the process is, I'm not sure I understand the need to remove a masking layer in developing. Won't that layer (presumably a colloidal silver yellow filter layer like the ones found in C-41 and E-6 materials) be removed in the bleaching and fixing steps, just like the developed silver image?
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  10. #30
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    Skip
    There are four different papers available for cibachrome printing that have the melimex base and high gloss( these are the only papers I use) as well there is an rc version , which I do not use .
    CFK= LOW CONTRAST
    CLMK= MEDIUM CONTRAST
    CPS = HIGHER CONTRAST
    UNIVERSAL = LAMBDA OR DIGITAL WRITER ( I have used this under enlarger no problem) characteristics mimic cps but the blue rendition is much better.

    My crystal ball predicts Ilford will at some time cut production of the cut sheet versions and will only produce the universal.

    this will present some problems for enlarger base printing but is easily fixed by followings Donald Millers advice on contrast masking. I have read his article and also posts and he definately has a good grasp on contrast control.
    You would be able to make masks to control contrast if Ilford decides to downsize the paper selection.

    At the moment I am using only universal under the enlarger and with the lambda. If the transparacy is normal I will print traditional, if the trans is dirty, contrasty , I will print using lambda and photoshop.

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