PC-TEA 1:100

Discussion in 'B&W: Film, Paper, Chemistry' started by Alan Johnson, Sep 30, 2005.

  1. Alan Johnson

    Alan Johnson Subscriber

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    With T-max 100 I develop for 22min 68F, agitated 30s then 2 inversions/min.(All times for 500 ml tank) Gives finer grain than 1:50,high resolution,suitable for sunny landcsapes at EI 64 and for portraits(no Mackie lines). Higher acutance than Xtol 1:3 IMO. Acros 18min and Delta 100 20min I found also good, slightly more grain.Care, not possible IMO to make hot TEA completely risk free.

    My tests with T-max 100 show the 1:100 dilution gives finer grain (similar to D76 1:1) than the 1:50.The pH has been reported to be 1:50-9.07 , 1:100-9.01.As these are similar I cannot explain the finer grain with the 1:100.

    Any other PC-TEA comments?
     
  2. aligndont

    aligndont Member

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    Agitation with 1:500 pctea

    Jay
    With 1:500 dilution of pc tea are you only agitatating at the beginning of the process or intermittantly, say every 15 minutes. And if were talking about a roll of 120 or 36 exposure 35mm how much solution have you been using ? I presume you are using temperature of 70 F. I find that that Delta 100 closely matches FP4+ in developing times and temps.. Have you found this to be so in extremely dilute PC tea?

    I must say that this seems quite inexpensive.

    Michael
     
  3. gainer

    gainer Subscriber

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    I am going to let you in on a secret. I debated about revealing this for quite a while. It is not necessary to heat the TEA any more than necessary to reduce its viscosity. Lukewarm will do. Let's say you want to make a liter of PC-TEA stock. Take 100 grams ascorbic or erythorbic acid, 2 grams phenidone, and 100 ml water. Mix them and heat until dissolved to form a clear solution. Immediately add enough lukewarm TEA to make a liter. It will dissolve directly with a little stirring. Thus you are heating water, not the TEA, no more dangerously than when you make tea to drink.

    I have tested this mixture two ways. A drop of the concentrate on a snip of film in room light will not blacken the film in 2 minutes. 100 ml of the stock left standing two days in an open 1/4 liter measuring cup was still as active as when first mixed. This brings me to believe that the stock with this small amount of water will last as long as needed. Of course, if you are diluting it 1:500, you will probably only need to make 100 ml at a time.

    I really didn't think it would work at that dilution, but then I never thought of leaving it for an hour. Are you sure there is not something else in your water? Coffee grounds, maybe?
     
  4. gainer

    gainer Subscriber

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    P.S.: This method leaves the stock solution much less colored. It also works with ascorbic acid, phenidone and glycol. It will not work as well for mixing TEA or glycol and hydroquinone as the same amount of hot water makes a paste with hydroquinone. Hydroquinone is very soluble in alcohol, so I plan to try using alcohol to do the same trick.
     
  5. Alan Johnson

    Alan Johnson Subscriber

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    Jay,thanks, I will try the 1:200 for 1 hour with some Pan F. I wonder if this will make light lines round dark objects in the print.

    Patrick,thanks for details of the low temperature method of making PC-TEA. I will make 200ml by this method and see if it lasts a few months,that would be OK.
     
  6. gainer

    gainer Subscriber

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    I have since learned that I can get by with 7.5 ml hot water per 10 g ascorbic acid. At some temperature it makes a clear solution to which you can add the lukewarm TEA. I have a feeling that the first thing that happens when the TEA meets the hot water solution is the formation of some compound that is like an analog of sodium ascorbate. I don't really care as long as it works.
     
  7. Maine-iac

    Maine-iac Member

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    While I'd never deny anyone their pleasure, you guys must have a lot more patience for film developing than I do. I look for formulas that are going to shorten my development time to the maximum while still giving me the fine grain and high acutance I want. I hate standing there for a long time watching the timer go around and inverting every 30 seconds, even if "Car Talk" or "Wait, Wait, Don't Tell Me" is on NPR. I recognize that I am easily bored, however, and that other people have a lot higher boredom quotient than I do. This is no criticism; just a personal confession.

    My Delta-400/PCM (Phenidone, Ascorbic, Metaborate) combo gives me 6 1/2 minutes at 70 F, and I can enlarge my 120 negs to the largest size I ever print and still barely see the grain. With ACROS, I substitute carbonate for the metaborate to shorten the time to 7 1/2 minutes (the metaborate formula takes 9 1/2) and get superb sharpness and no grain at all that's visible in an 11X14. I wouldn't want to go much shorter than these times because of the risk of uneven development, but for the life of me, I really don't understand the need for longer development times. I know there are plenty out there who would argue with me that one can reach the ultimate in acutance or edge-adjacency effect, etc., with long times, but who's looking at this stuff with a microscope? I rarely print bigger than 16 X 20, and most of the time am happy with 11 X 14 or 8 X 10, and at those sizes I get all the sharpness and fine grain I can handle.

    Larry
     
  8. gainer

    gainer Subscriber

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    I'm with you on that. I don't always trust stand development and don't much like watching the clock for agitation. I am considering making an agitator out of an old child's phonograph, if I can find the phonograph. I use PC-TEA at 1+50 in the summer when 75 F is easier to get than 70 and use 8 minutes for normal contrast. 1+25 is still economical. I also use PC-Glycol and either Kodalk or carbonate as split stock with a wide range of contrast and developing times available. The Kodalk I use is the same as for PMK and the carbonate is the same as for Pyrocat HD. That way I don't have to keep too many bottles around. I do keep a lot, but that is because I do a lot of experimenting and hate to throw anything away. Once in a while, I looK at a bottle that I didn't label because I was sure I would never forget what is in it and wonder what is in it. That I can throw away.
     
  9. Alan Johnson

    Alan Johnson Subscriber

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    Larry,

    You refer to the use of 120 film and I can believe that you obtain excellent results with your developers at 11x14 with this format.But I am using 35mm film and trying to approach the same standard so the grains have to be that much smaller,hence the PC-TEA 1:100 and this needs the long time.I have a cup of coffee.And I like the grains sharp so no sulfite for me either.

    Alan
     
  10. Maine-iac

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    Though the spirit doesn't move me very often, I do occasionally shoot the odd roll of 35mm Delta. My PCM formula works great with it, and I do get very fine, sharp grain. Not, to be sure, the equivalent of the 120 film-- there really isn't any substitute for negative size, not even Tech Pan which I used to shoot a lot in 35mm. Even when the resolution holds, the tonal qualities are just not the same. It's why I eventually gave up on 35, despite the fact that I cut my photographic teeth on a brace of Leica M-3's and Summicrons. (Come to think of it, my early Leica period may explain why I favor the Fuji 645 and 67 rangefinders now. They're just big Leicas, and I use them, especially the 645's in much the same way for "street shooting" on-the-go photography.)

    Larry
     
  11. Alan Johnson

    Alan Johnson Subscriber

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    My tests only showed that PC-TEA 1:100 is finer grained than PC-TEA 1:50.I kind of assumed Larry's developer would be similar to the PC-TEA 1:50 for grain.I wonder if anyone would care to comment on how the other Vit-C developers really compare to PC-TEA 1:50.
     
  12. fhovie

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    In my opinion - the best vitamin C developer on the planet is XTOL or a variation of XTOL called MYTOL. Mytol uses sodium ascorbate instead of ascorbic acid and does contain sulfite. I have used it to push process 120 TRI-X to 1600 and make 16x20 prints that were wonderfully sharp and smooth with very little grain. The reason I do not use it for everything is that it doesn't have many of the properties of staining developers and it has a finite shelf life - maybe 6 months. It is not expensive to make and it is not very toxic.
     
  13. gainer

    gainer Subscriber

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    The difference between ascorbic acid and the ascorbate is a tiny bit of carbonate or bicarbonate or borax or Kodalk. It would be better if you did use ascorbic acid and baking soda in place of the ascorbate, as the ascorbate powder does not keep as well as the acid. Use 2.1 g ascorbic acid and 1 g baking soda for each 2.36 g sodium ascorbate. Mix them in a little water and let the fizzing subside before mixing with the rest of the ingrdients. You can use this with any formula calling for sodium ascorbate.

    In PC-TEA, the salt of ascorbic acid is of TEA, which I suppose makes it an analog of ammonium ascorbate. You will find that it too will make wonderfully sharp and smooth negatives and will have a much longer shelf life. You might try reducing the sulfite in the Mytol to see if it makes any difference. Most who formulate developers containing sulfite seem to take as a given that it will have 80 grams or more. In the case of ascorbate developers, you can go all the way to zero with no fear of staining. The next time you mix a batch, try using it before you add the sulfite, just for fun.
     
  14. Maine-iac

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    Pat,

    Can you remind me once more why ascorbate is to be preferred over ascorbic acid? Not sure I understand the rationale. If the acid keeps better, why not just use it instead of ascorbate in any formula that calls for it?

    Larry
     
  15. gainer

    gainer Subscriber

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    In any of the developers that are, like Xtol, water solutions with developing agents, activator and preservative, and in my own sulfite free developers, whether you use ascorbate or ascorbic acid is immaterial in the working solution, since whatever base you are using as activator will provide whatever is needed to give the ascorbate part of sodium ascorbate when it is needed in the reaction. In water solution, the sodium and ascorbate parts of sodium ascorbate are pretty much free to behave the same as if you had put sodium hydroxide and ascorbic acid in the solution. I do not know why there are formulas calling for sodium ascorbate and formulas calling for ascorbic acid. The pH will certainly be different if you substitute one directly for the other, but if you make sodium ascorbate out of ascorbic acid and baking soda in the proper proportions, you will get sodium ascorbate and carbon dioxide. True, the CO2 in water is slightly acidic, which is why carbonated beverages tingle the tongue, but using a minimum of water and allowing most of the CO2 to escape (go flat) will make that not a serious hazard. If you used the right amount of sodium hydroxide, there would be no CO2 and the pH would be the same as if sodium ascorbate had been used. Many are loath to use NaOH, even though it was used for many things in house and shop by their parents and grandparents, of whom I am one.

    At any rate, the specification of sodium ascorbate is not written in stone. I can think of valid reasons for preferring the acid in split stock developers, as a low pH generally prolongs storage life.
     
  16. Jordan

    Jordan Member

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    The formula for MYTOL calls for sodium ascorbate. In principle, you could just substitute ascorbic acid and add enough base to make up for it (sodium metaborate in the case of MYTOL). My guess is that they use sodium ascorbate (which forms slightly alkaline solutions in water on its own) as the starting material so that less base will be needed, either for cost savings or because you would have a solubility problem for the metaborate.

    Sometime soon I plan coming up with a MYTOL-like formula that uses ascorbic acid directly instead of sodium ascorbate (without the need to pre-neutralize with NaOH or NaHCO3). I'll post my results.
     
  17. Maine-iac

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    Thanks, both of you for the explanations. I think that since I've got my Phenidone/Ascorbic Acid/Metaborate formula working so well and giving me the kind of negs that almost print themselves, I'll forego the joys of experimenting with ascorbate. My 1/2 tsp. AA, 1 tsp. Kodalk, and 2.5 ml Phenidone stock is so easy and so consistent and so fine-grained and sharp that it's pretty hard to beat. With ACROS or Delta 100, I can substitute 1 tsp. of carbonate for the metaborate and shorten the development time from 91/2 minutes to 7 which I like better, with no visible increase in grain.

    Larry
     
  18. mongo141

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    Hi , Have you tryed the PC-TEA with one of the alcohols in place of the water? I Have plenty of Methanol out in the shop. I ask because I made up some of the "basic" PC-TEA formula and about an hours stirring didn't seem to dissolve all of the A/A in 170 deg TEA. I dislike using water in developers until I am ready to use the stuff since film developing around here sometimes gets rather sporatic. Dave

     
  19. gainer

    gainer Subscriber

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    I haven't tried it recently. I don't think methanol gives the same protection against aerial oxidation, but I really don't know why. I'm fresh out of methanol. They will only sell one 12 oz bottle of it at a time, in the form of gasoline drier. Afraid I'll start a meth lab, I guess. I think they would call the cops if I tried to buy Pseudephedrine and methanol at the same time.

    The small amount of water that aids in the solution doesn't seem to have any effect on storage life. You could try the methanol, but it will still probably have to be heated somewhat, and for that I recommend a water bath. Methanol is much more volatile and combustible than either TEA or propylene glycol. Its octane rating is 100.

    According to the CRC handbook, ascorbic acid is very soluble in water, but only soluble in alcohol. Hydroquinone is the other way round.
     
  20. mongo141

    mongo141 Member

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    Ok, well I may try it time permiting as I have plenty of the stuff left over from my racing days but you are probably right. There should be a bounty on dopers and all of their ilk, You know, turn their ears (or something else) and get a $1.00. Dave

     
  21. Tom Hoskinson

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    Try Isopropyl alcohol (aka Propanol, IPA, rubbing alcohol). Get the 99% or 90% stuff from the supermarket shelf. It should work as well (or poorly) as methanol.

    If it doesn't work (dissolving A A), you can always use it as lens cleaner.