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  1. #11

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    Quote Originally Posted by Ian Grant View Post
    Heather, Photocolor has been around for a long time, the company who originally made it were the successors to Johnsons Photochemicals, Pip Pippard was the chemist.

    Now I think they are made by Paterson. But for many years they were predominant in the UK market for their C41, RA4 and E6 kits.

    It's available online at Retro, but maybe its not currently manufactured, Paterson have only just resumed B&W chemistry after their outsource manufacturer stopped making photo-chemicals in the UK.

    Ian
    Paterwson no longer produce RA4 or C41 developers. I e mailed them to ask and that's what they told me.
    Cheers
    Jeff

  2. #12

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    As Jeff has confirmed, Paterson no longer does RA4 or C41 kits. Their supplier, Champion I think, moved, I believe, to Spain and there seemed to be a problem with the quantities Champion would have required Paterson to buy per consignment. Paterson's sales might have left it with stock on the shelves too long.

    Pity. It was easy stuff to use and relatively cheap.

    I couldn't find any mention of Photocolor on the Retro site. It seems to only deal in Tetenal kit. Most of the off the shelf kits for the low volume user have C41 blix not separate bleach and fix. Again a pity. Morco for one does the Kodak kit which has separate bleach and fix but not in small quantities.

    If anyone were to find old Paterson photocolor C41 or RA4 stock for sale, he should be wary as it has to be quite old stock now.

    pentaxuser

  3. #13
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    I started doing my own C41 earlier this year. It's really easy, and my results have been good. I use the Tetenal 5 litre kit, which uses a blix, but that hasn't caused any problems yet - possibly because I don't run it to exhaustion.

    I decided to get a jobo processor off e*bay, as I wanted better temperature control and auto rotation, but you don't actually need one.

    It's much cheaper than having it processed commercially, and the results are just as good.
    You can also take the executive decision not to charge for pushing and pulling films
    Lens caps and cable releases can become invisible at will. :D

  4. #14
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    Fotospeed, unlike Paterson's chemicals, are still around; I think I bought mine from Firstcall, but I've seen them in other online shops.

    Don't have much to say as I've only just started dev and printing my own colour too (and most of that cross-processed...) and have been using Tetenal C41 and Fotospeed RA4 although I will probably buy Kodak C41 chems when the Tetenal runs out - I just wanted something simple for my first few rolls.

    I already have a Jobo CPE2, so keeping the C41 at 38C is fairly straightforward. Without such equipment, a tempering bath of hot water is required to hold the working chems - possibly in an insulated container such as a picnic cooler.

    Have fun, Bob.

  5. #15
    AgX
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    Quote Originally Posted by Photo Engineer View Post
    This is why Kodak, Fuji and Agfa never released a blix for any color film product.

    So, these companies recommended a C41 process which was prewet, color developer, bleach, wash, fix, wash and stabilzer.

    Agfa offered within their AP70 process chemistry range (compatible with C-41) a so called `AP 70 Kit´, which used a bleach-fix.
    [Aside from 37,8°C a process temperature of 30°C was advised without limitations.]

    Agfa did not advise a prewet (if you mean wetting the film before employing the coulour-developer) for their CN processes, nor have I seen any hint at that in any other datasheet.

  6. #16
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    Quote Originally Posted by AgX View Post
    Agfa offered within their AP70 process chemistry range (compatible with C-41) a so called `AP 70 Kit´, which used a bleach-fix.
    [Aside from 37,8°C a process temperature of 30°C was advised without limitations.]

    Agfa did not advise a prewet (if you mean wetting the film before employing the coulour-developer) for their CN processes, nor have I seen any hint at that in any other datasheet.
    I am sure that they could devise one just as we did at Kodak, but the keeping quality of a film blix is very low. It would probably be close to a one shot blix if it removed all of the silver.

    OTOH, it may only have worked on Agfa films. IDK.

    Here is a good blix process for C41.

    Develop in C41 developer

    Stop in 2% acetic acid + 10 g/l sodium sulfite (clearing stop) for 2 minutes

    Wash 2 minutes

    Blix in 50 g/l Potassium Ferricyanide + 200 ml /l of 60% ammonium hypo for about 5 minutes then throw this solution away.

    Wash 10 minutes

    Stabilize.

    This is all at 100F.

    That should work, as the Ferricyanide/hypo blix was one of the earliest and least stable and would never survive a deep tank replenished process.

    BTW, I have not tried this with current films so I do not warrant the process. I have not done this since about 1970 or thereabouts.

    PE

  7. #17
    AgX
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    Tetenal state for their `fast blix´ (4min in contrast to Agfa's 10min blix) a shelf life of the working solution of 2-4 weeks.
    Well, they don't state whether this is for fresh or used blix.



    But what about that `prewet´ thing, PE?

  8. #18
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    Either way, at a useful pH and at a high enough concentration to blix modern C41 films from Kodak and Fuji, the lifetime of the hypo will be rather short. A good blix for fillm, using hypo, will need ammonium salts and will begin to go bad the minute the two parts are mixed. One part is an oxidant and the other is a reductant.

    BTW, Kodak RA blix mixed at 2x concentration and then brought down to pH of about 4.5 (it turns orange like orange juice from the original blood red color) will make a passable blix for C41 film, but is only stable for hours.

    PE

  9. #19
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    I would like to add that I spent nearly 50% of my time for over 5 years on the subject of blixing C41 films and have a patent on the topic with 2 of my co-workers. I also designed the current paper blix which is esssentially unchanged from my original formula of 10/1966.

    PE

  10. #20
    AgX
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    PE,

    I know about your work on blixes and your knowledge is highly appreciated.

    I just referred to the fact that other companies offered blix processes. Whereas that very Agfa chemistry was seemingly intended for amateur use, the Tetenal chemistry is intented for rather large volumes of working solution too, especially allowing repeated runs with blix solution.
    From that I conclude that it works. The quality of such a blix-process may be another issue…


    And again:
    You referred to the use of a pre-wet. There is no hint at such in any type of C-41 datasheet I got.

    Did I miss anything?

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