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  1. #11
    Photo Engineer's Avatar
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    My darkroom is configured for emulsion making and B&W processing. I do color film as well, but I cannot easily do color printing, so my workflow is hybrid at the present time. I do 35mm, 120 and 4x5. I do 120 in two formats. So, I strive for the ultimate quality in the negative and reversal film processes.

    That is the source of my comments. And, it is also based on the number of complaints here about substandard sharpness, color and grain on color materials which may also be due to less than perfect color chemistry.

    So, that is just my POV.

    PE

  2. #12
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    Quote Originally Posted by analog what is that? View Post
    Well since you already know whats so wrong with the recipes, why don't you just publish a better or "correct" version?

    Kodak is going bust, there is virtually no money to be lost or gained in this in the future, so it should be quite OK to do so, just to satisfy the curiosity.....
    OK;

    E6 uses HQ Monosulfonate not HQ. It does not use KSCN, but rather is more like the B&W motion picture film first developer and uses DTOD. The Thiocyanate is incorrectly placed in the Color Developer!!!! It goes in the 1st Developer.

    The level of KI and NaBr must be balanced (and both must be present). Ditto for the C41 CD.

    Ferricyanide was not specified in the original test conditions for E6 or C41 and therefore the image stability can be called into question unless the tests are run. Both films were designed for milder bleaches using sequestered Iron III. If Ferri is used, the least one can do is use a clearing bath as was used in E3 and E4 to insure that stain does not form.

    The rinse after the bleach is too short for a Ferri bleach and can lead to decomposition of the fixer just like Farmers Reducer or the like.

    All E6 and C41 fixers are at an acidic pH (about 6.5) and use Ammonium salts. Sodium salts are too slow and ineffective for the high Iodide and DIR environment of the thicker color films. A slightly acid pH is suggested for best results in hue and stability.

    Those are a few for starters. Now, you ask why I can't be more specific and that is due to the fact that I handed in my formulas for the developers and bleaches when I retired. I can give you formulas for the C41 Bleach I and the Fixer because I worked on them. I simply cannot remember all of that in my head except for the notes I have which I have reproduced above. In fact, I have given those two formulas and the stabilizer formula here on APUG several times.

    Hope this is enough. You should realize that individuals have come up with these by guess and by golly, not by having the actual formulas. Those that have read the formulas or who have worked with them can tell whether they are right or wrong, but may not be able to reproduce them exactly. The formulas will work, but may not work with all films.

    PE

  3. #13

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    Thank you Ron. I appreciate your input.

    On a positive note : "The formulas will work, but may not work with all films"

    This probably opens for a round of try-if-it-works situation, much like Caffenol and such-like, and with a simple adjustment according to what Ron wrote above here, it might work for all films and work with excellence for many!?

  4. #14
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    Or, work with none, or most unhappily appear to work but ruin image stability for long term storage (a result I doubt).

    Anyhow.

    PE

  5. #15
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    Interesting brochure. Nothing new. In fact, it is organized and reads as if lifted directly from the related chapter of Developing by C.I. Jacobson & R.E. Jacobson.

  6. #16
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    Quote Originally Posted by BradS View Post
    Interesting brochure. Nothing new. In fact, it is organized and reads as if lifted directly from the related chapter of Developing by C.I. Jacobson & R.E. Jacobson.
    Jacobson's book Developing and also Enlarging are still the best books of their type, but remember that there were many other Focal Press books which used the same information. L.A.Mannheim also contributed to many of them and had a good technical grounding in photography as well, working as a technical writer for Jacobson's companies.

    So the same information is used extensively in the 3 different versions of the Focal Encyclopdia of Photography (Full edidition, Desktop edition and Pictorial Cyclopedia) and of course there were many editions of these books as well

    Ian

  7. #17
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    Interesting to note that there are formulae for "Wash Aid for Paper Prints" (Na Carbonate) and "Hypo Eliminator" (H202 + NH3), but not the sulfite HCA mixes that are used nowadays.

    When did the 'modern' HCA become commonplace? I seem to remember using in the late 70's with the knowledge that 'eliminator' wasn't ideal from a permanence stance.
    - Ian

  8. #18
    Ian Grant's Avatar
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    Ian, Agfa recommended Carbonate as wash aid right up until the consumer Photo division closed down.

    Mason mentions Sulphite in his 1966 book Photographic Processing Chemistry. Permanganate was also used like Peroxide to break down Thiosulphate.

    Ian

  9. #19

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    I used to buy chemicals from them years ago and they supplied this booklet which I still have. It is a pity that they are no longer in business.

  10. #20
    Ian Grant's Avatar
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    They must have been quite small, Rayco and Hogg Lab supplies were the two main suppliers listed everywhere for photo chemicals in the UK.

    Rayco also produced similar booklets of formulae etc and also made timers and other equipment for colour work. Hogg's on the other hand were a larger chemical supplier selling to schools, univerities and laboratories and Ninian Hogg had a separate store room just for specialist photographic chemicals. Back in the late 1980's a few years after they'd moved I bought the entire stock after Mike decided to pull out of Photo chemicals, not long after he sold the company which was merged with Scientific and Chemical Supplies.

    Rayco themselves were sold and moved up North where they were part of a Pharmacy shop until the shop owner wound them down, I did approach them to take over & buy the company but it had been sold two days earlier and just disappeared.

    Ian

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