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  1. #11

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    Quote Originally Posted by arigram
    So, what is PC-TEA good for?
    It is used for developing film.

    Sandy

  2. #12
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    Quote Originally Posted by sanking
    It is used for developing film.

    Sandy
    Bravo! It's about time someone told the truth.
    Gadget Gainer

  3. #13
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    You mean that you're not supposed to drink it with Lemon and Sugar?! :o Ptoooi!!!
    That is called grain. It is supposed to be there.
    =Neal W.=

  4. #14
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    Quote Originally Posted by Flotsam
    You should probably edit that in the original post. If someone just searches apug or google on PC TEA they might just see the errant formula and ruin some film and waste some chems.
    The original post was in Photo Techniques Magazine under the title "The Role of Antifreeze in the Photographic Process"

    You might use more phenidone than necessary, but I don't think you would ruin much film. There is a ratio of ascorbic acid to phenidone that is optimum but if you hold ascorbic acid constant and increase phenidone, the curve of contrast index vs phenidone content will flatten out. I did test the other way round, holding phenidone constant.

    I will test the erroneous formula to see if it does ruin film. If your own test seems to show too much phenidone, you can dilute the stock with more of everything else: more TEA and more ascorbic acid.
    Gadget Gainer

  5. #15

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    I am unclear as to the advantages of this formulation over, say, Pyrocat (which is what I use now). What is there to gain,besides increased activity, in a switch to PC-TEA? Am I missing something???

  6. #16
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    Quote Originally Posted by gainer
    The original post was in Photo Techniques Magazine under the title "The Role of Antifreeze in the Photographic Process"

    You might use more phenidone than necessary, but I don't think you would ruin much film. There is a ratio of ascorbic acid to phenidone that is optimum but if you hold ascorbic acid constant and increase phenidone, the curve of contrast index vs phenidone content will flatten out. I did test the other way round, holding phenidone constant.

    I will test the erroneous formula to see if it does ruin film. If your own test seems to show too much phenidone, you can dilute the stock with more of everything else: more TEA and more ascorbic acid.
    I have no clue what effect using the formula with the misplaced decimal point would have on the film. I'm strictly a recipe follower. I only mentioned it because when I became interested in your formula, I just searched on the name and found it on APUG. Without a basic knowledge of photo chemistry, I would have followed the formula unquestioningly to the letter even if it had mistakenly called for a cup of Chicken broth . I just thought that correcting the the formula in the might help avoid confusion among recipe followers like myself.
    That is called grain. It is supposed to be there.
    =Neal W.=

  7. #17

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    Quote Originally Posted by sanking
    ...What I found was that adding 0.2g of potassium bromide per 100ml of stock solution of PC-TEA reduces B+F of the films mentioned above to about log 0.08, without reducing the activity of the developer. The exact amount is very critical because more bromide will result in loss of energy while less leaves you with a high B+F. I add the bromide directly to the stock solution when mixing, after the ascorbic acid goes in but before the phenidone.

    Sandy
    Would the addition of bromide increase edge effects? On the grounds of decreased activity of the developer near dense areas?

  8. #18

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    Quote Originally Posted by Daniel Grenier
    I am unclear as to the advantages of this formulation over, say, Pyrocat (which is what I use now). What is there to gain,besides increased activity, in a switch to PC-TEA? Am I missing something???
    Actually, Pyrocat-HD, even with the 1:1:100 dilution, is a more active developer than PC-TEA. And, at least from my own comparisions, Pyrocat-HD (because of grain masking) gives slightly finer grain than PC-TEA. Both give very high acutance, though the physical method of development matters a lot when maximum acutance is the issue, and in many cases is more important than the developer itself.

    PC-TEA has a convenience factor in that it is a one-solution developer. Like Rodinal, you just dilute it with water. And it gives much finer grain than Rodinal.

    Pyrocat-HD is my developer of choice for most applications, but there are times when a non-staining developer may be desired, and at those times, voila PC-TEA. Much cheaper than Rodinal, and better results. Unless of course you like the golf-ball size grain of Rodinal.

    Sandy
    Last edited by sanking; 12-15-2004 at 10:22 PM. Click to view previous post history.

  9. #19
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    PC TEA also gives full film speed - which is one advantage over pyro - especially for push processing - I am not sure the grain of PyrocatHD is smaller that PC-TEA. I am certain that XTOL is finer - it contains sulfite though. - which means there is a trade (PC-TEA and XTOL) - some sharpness for some finer grain. Not a big trade in this case though. I use pyrocat exclusively for LF with no regrets - I am not always happy with bigger enlargments on roll film in pyro - at least Pyrocat is a lot finer than PMK.

  10. #20

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    Quote Originally Posted by jdef
    I am not sure what advantages in results PC-TEA offers, because I don't use pyrocat, but there are some ancillary benefits to be had, such as greater shelf life, single solution/ease of use, lower toxicity, simplified densitometry, and economy. Wether or not any or all of these benefits are enough to warrant a switch from your current developer is for you to decide, based on your own work. If you are enlarging your negatives, your question could reasonably be reversed; what is there to be gained by using pyrocat over PC-TEA? To which, I would answer; nothing that I can think of.

    Jay

    The issue of shelf life of Pyrocat-HD (or of PMK or Rollo Pyro for that matter) versus a developer such as PC-TEA is really a non-issue. The simple fact is that the Stock A solutions of Pyrocat-HD, PMK and Rollo Pyro can be mixed in propylene glycol with a resulting shelf life as long as that of PC-TEA, or any of the -TEA developers. And there is no need to be concerned about the shelf life of the Stock B solutions of these developers because it is on the order of years and years. Moreover, both PMK, Pyrocat-HD and Rollo Pyro can be mixed in TEA if desired, without the necessity of a Stock B solution, giving the same single solution advantages of PC-TEA.

    However, there are some important reasons why one might choose a staining developer over a non-staining developer. The issue is fairly complex and persons interested in more detail might have a look at my article on pyro staining developers at http://unblinkingeye.com/Articles/PCat/pcat.html.

    Sandy

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