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  1. #1
    fhovie's Avatar
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    PC TEA - The new frontier?

    I was delighted with the performance of my home-made XTOL (MYTOL) - but not delighted with the same old D76 deterioration on the shelf and the mixing of large stock solutions with limited capacity. So I just tried PC-TEA hoping to get the same performance I was getting with MYTOL but with the convenience of a 50:1 stock solution with unlimited shelf life. My first try using
    400ml TEA at 250 F
    45g Ascorbic Acid
    1.25g Phenidone
    last 100ml TEA
    50:1 at 68 F
    was TRI-X pushed to 1600. 14 minutes with 5 sec agitation every 30 sec.
    All my shadow detail is there and the film looks great - I will soon know if the grain is tight and by looking at it, it doesn't seem to have that N+2 look I was expecting and half hoping for - I may try a three stop push if it doesn't have the contrast expansion I was looking for. (Dusk shots with very low contrast)

    Should I add Benzotriazole or Potassium Bromide? I don't seem to have any streaking or fogging now but I will certainly be using this for FP4 (if it can be purchased ... ) and other films as well. I am also hoping the grain will be as fine as the MYTOL I was using - (which had some sulfite in it) I would like microdol fineness with acufine speed ... with pyro accutance - throw in the moon and stars and I will not have to experiment for at least a few weeks!

    Any advise from the pros would be very appreciated!

  2. #2
    gainer's Avatar
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    I don't use restrainer, but then I can stand a little base fog. 35 mm HP5+ has a base density of about 0.2 even when you remove the emulsion. neither benzotriazole nor potassium bromide can do anything about that part of the fog. I don't think the sheet film has that in the base, the antihalation being provided by a dye in the gelatin coating on the back of the film which washes out in the processing. You will just have to try it for yourself unless someone else chimes in. It is easilly added to the concentrate or to the working solution. I do keep a saturated solution of KBr handy, a few drops of which does the job on paper. Do a test without restrainer for your personal satisfaction.
    Gadget Gainer

  3. #3
    arigram's Avatar
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    You are welcome to throw at me any curse words in the book, but I want to ask:
    - What the hell is PC-TEA?
    I keep reading about it a lot in APUG but apart from being a film developer, I don't know anything else about it! It is just home made or can be found ready?
    Anyone kind enough to enlighten this cave-dweller?
    aristotelis grammatikakis
    www.arigram.gr
    Real photographs, created in camera, 100% organic,
    no digital additives and shit




  4. #4
    gainer's Avatar
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    TEA is short for triethanolamine, an organic liquid solvent and base. It will dissolve most of our developing agents to an extent useful in making concentrated stock solutions. It does not become basic until water is added.

    PC-TEA as used here is:

    100 ml TEA
    9 g ascorbic acid (erytorbic acid, AKA isoascorbic acid works as well)
    2.25 g phenidone

    Heat this mixture to about 160 F and stir till it dissolves. It will stay dissolved after it cools. If it gets a brown color, don't be worried. TEA by itself turns brown upon sufficient heating. At 160, it shouldn't be any darker than HC110 concentrate.

    This concentrate is diluted 1+25 or 1+50 for use on film. I don't want to brag too much, but it's pretty good stuff. Note that there is no sulfite. If you think there should be, add it to the working solution, but try it without sulfite first.
    Gadget Gainer

  5. #5
    gainer's Avatar
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    I put the decimal in the wrong place. It should be 0.225 grams of phenidone.
    Gadget Gainer

  6. #6

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    Quote Originally Posted by gainer
    I don't use restrainer, but then I can stand a little base fog. 35 mm HP5+ has a base density of about 0.2 even when you remove the emulsion. neither benzotriazole nor potassium bromide can do anything about that part of the fog. I don't think the sheet film has that in the base, the antihalation being provided by a dye in the gelatin coating on the back of the film which washes out in the processing. You will just have to try it for yourself unless someone else chimes in. It is easily added to the concentrate or to the working solution. I do keep a saturated solution of KBr handy, a few drops of which does the job on paper. Do a test without restrainer for your personal satisfaction.
    As an alternative printer I abhor any type of B+F that is in excess of the theoretical minimum. When one processes fresh FP4+ (or Delta 100 or Tmax-100) sheet film in developers such as D76, Xtol or Pyrocat-HD the B+F is about log 0.06. Processed in PC-TEA with no restrainer the B+F is around 0.20. This amount to almost 1/2 of a stop loss in printing speed, which can amount to a very long time when printing with a UV sensitive alternative process where printing times are in the minutes or tens of minutes.

    I did some tests with PC-TEA in an effort to reduce B+F without loss of activity or energy level. 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

  7. #7

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    TEA

    TEA = TriEthanolAmin

    what i really hate about it is the high viscosity of TEA/the concentrate.

    best regards, --- jan.

  8. #8
    Flotsam's Avatar
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    Quote Originally Posted by gainer
    I put the decimal in the wrong place. It should be 0.225 grams of phenidone.
    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.
    That is called grain. It is supposed to be there.
    =Neal W.=

  9. #9
    fhovie's Avatar
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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.

    Sandy
    That is exactly what I was looking for - Thanks!!

  10. #10
    arigram's Avatar
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    So, what is PC-TEA good for?
    aristotelis grammatikakis
    www.arigram.gr
    Real photographs, created in camera, 100% organic,
    no digital additives and shit




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