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  1. #11

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    Kirk,

    I use tube development, with constant agitation, and develop with the tubes in a water bath, which provides the most even development possible. However, development of sheet film in 8X10 trays should give good evenness as well. The differences between these two developers in terms of energy level, though not subtle, is also not huge, so some degree of attention to detail is required.

    My testing also incorporates an 80A filter so we are on the same base there. As for exposure time, one second is too long and will take you into reciprocity with FP4+, which might compromise the results. If possible, adjust the aperture of the lens and don't expose any longer than 0.5 seconds.

    For several years I tested by exposing three different step wedges at a time, for the reasons you mentioned. However, I switched to the Stouffer TP 4X5 several years ago and now use it for all of my testing. I have several of these, but one is dedicated to film testing, and I do check the densities from time to time to make sure they are the same as the densities that are used by the graphing software.

    Sandy
    Last edited by sanking; 05-22-2005 at 04:56 PM. Click to view previous post history.

  2. #12

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    Moving away from the issue of testing and back to the issue of the developing characteristics of Hypercat itself ,I want to mention a couple of the reasons why I don't think it is an optimum formula, and both have to do with the choice of activator.

    First, sodium hydroxide is a rather nasty thing to work with. It is in fact the chemical that is in Red Devil Lye, and if you read the bottle it says Poison. Now, I am confident that most of us here are able to safely use sodium hydroxide, but if better results can be had with something else why run the risk?

    Second, and much more important, is the question of buffering. In a private email with Jay some time ago I expressed my belief that the carbonates are better all around activators for pyrocatechin based developers than the hydroxides, and that one of my concerns was the buffering quality of the hydroxides. As I recall, Jay's response was that he had not seen any evidence of a problem. Well, if you look at the comparison curves I provided of FP4+ and HP5+ the evidence is plainly visible. The developer with hydroxide peters off in activity compared to the one with carbonate. You will see, for example, that the contrast produced by Pyrocat-HD and Hypercat at four or five minutes is very similar, but look what happens with increasing times of development. While the build up of contrast remains very constant with the carbonate developer the one with hydroxide slows down considerably after about six or seven minutes.

    Obviously, if one’s goal is to design a very fast acting developer that will develop film to a desired contrast within a short period of time one might be able to make a good case for hydroxide, but for a general purpose developer that might be asked to serve a wide range of applications I don’t think it is a good choice.

    Another and final issue is developer pH. The higher the working pH of a developer the more the film emulsion swells, which makes the film more susceptible to damage. This is an important issue, especially with the east European films, including Efke PL100, that appear to have rather fragile emulsions. The working pH of Hypercat is well over 12, and that is simply much higher than needed with pyrocatechin for most applications.


    Sandy

  3. #13
    c6h6o3's Avatar
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    Quote Originally Posted by jdef
    Sandy,

    I disagree with your characterisation of sodium hydroxide. First, it is no more poisonous than catechol, and if they sold catechol at the local grocery store, I'm sure it would bear a similar warning, among others.

    Jay
    Toxicity is the least of my problems with NaOH.

    I don't know what form you buy it in, but in solid form it's extremely caustic and volatile. The chemical burns it will cause may not even be apparent to the victim for quite a few hours, and they can be quite serious.

    Sodium Hydroxide is a substance I simply refuse to have in my house.

  4. #14

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    Quote Originally Posted by jdef
    Kirk,

    Jay,

    I disagree with your characterisation of sodium hydroxide. First, it is no more poisonous than catechol, and if they sold catechol at the local grocery store, I'm sure it would bear a similar warning, among others. I haven't tested much with carbonates, partly because I intended Hypercat to be a fast acting developer for expansion development with high DRs, and partly because when I got the results I wanted, I concentrated my efforts on that alkali.

    Jay
    Well, I don't agree with you at all. Even if sodium hydroxide is no more dangerous to work with than pyrocatechin, it is a lot more dangerous to work with than sodium or potassium carbonate. It is a caustic alkali that can cause severe skin burns in human beings, and may also soften the gelatin emulsion of film and make it more susceptible to damage. The fact that you have not yet experienced any problems does not mean that the dangers do not exist.

    I would also add that high pH caustic developers tend to be unstable, which may well result in inconsistent results. In my experimental work with the Pyrocat-HD formula some years ago the use of hydroxides was the only case where I was unable to replicate results with a second testing with a tolerance of about 0.05 or less.

    And the bottom line is that there is no advantage to the use of hydroxide over carbonate, unless extremely short developing times are your objective. If you look at the HP5+ curves in Pyrocat-HD and Hypercat that I posted you will see that they are almost equal in terms of energy level up to about 12 minutes of development, at which point both developers are producing far more contrast than would be required for printing with silver gelatin papers. So what do you gain by the use of a chemical that is potentially dangerous, may cause damage to the film emulsion and is unstable?

    As I suggested to you at some point in the past, if the carbonates don't satisfy the requirements of your application you should strongly consider the use of TSP, tribasic sodium phosphate. The pH produced by TSP in a working solution is about mid-way between the carbonates and the hydroxides, but tests show that it has much less gelatin softening effect than the latter. I experimented with TSP while formulating Pyrocat-HD and found that it had many good properties.


    Sandy
    Last edited by sanking; 05-22-2005 at 11:09 PM. Click to view previous post history.

  5. #15

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    Quote Originally Posted by jdef
    I think you're too eager to dismiss Hypercat, and allowing your personal antagonism for me to cloud your judgement.

    Jay
    I have no personal antagonism toward you, and wonder why you make such a statement? I do believe that you are very sloppy in your work, and I have very little respect for your methodology of testing, and have so stated many times. But this is not a personal issue.

    I am aware that some people on this forum appear to believe that you are rather ignorant, petty, nasty and something of a jerk. But whether I agree or don't agree with those opinions is irrelevant. In my exchanges with you I have tried very hard to stick to the facts at hand so as to not to allow my opinion of you as a person to impact my opinion as to the potential of your developers. Granted, this has not always been easy. But anyone with any degree of objectivity who takes the time to read the messages in which I presented my doubts about your Hypercat formula must recognize that the concerns expressed are entirely professional, and can be found in the literature.


    Sandy

  6. #16

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    Quote Originally Posted by jdef
    Kirk,

    thank you for the generous offer. If it's all the same to you, I'd prefer to provide the Hypercat for your tests.

    Jay
    I will provide both Pyrocat-HD and Hypercat. Kirk will therefore be free to test the two versions and determine for himself if there is any difference in results. Or, if Kirk prefers, I will send a small quantity of the dry chemicals themselves. He can mix with distilled water since there is no need to mix in glycol when the tests are to be done within the period of a week or so.

    This is in fact a important issue because the mixing of these solutions is quite crucial, given the small amount of phenidone and restrainer in the formulas (less than 0.3 g in both cases). Even a 10% difference in weight of either of these two chemicals can have a significant impact on results.

    In my own situation I use a scale with accuracy to 0.01 g. Jay has stated that he has a very accurate scale, but given the fact that I am on record with the opinion that Jay is very sloppy I have considerable concern about the reliability of his stock solutions.

    Sandy

  7. #17
    glbeas's Avatar
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    Sandy it might be advantageous for Kirk to test yours and Jays Hypercat developers side by side and see if there are differences in thier activity. It might point to a reason for the differing data points.
    Gary Beasley

  8. #18

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    Quote Originally Posted by glbeas
    Sandy it might be advantageous for Kirk to test yours and Jays Hypercat developers side by side and see if there are differences in thier activity. It might point to a reason for the differing data points.
    Gary,

    Basically I am pretty sick of of this developer discussion. I simply noted a contradiction in Jay's results, without in any way meaning for it to become a big deal. But Jay took it very personally and started to attack my work, and that got me going and sucked me into some testing that I quite would rather have avoided at this time.

    Regarding your question about Kirk's testing, of course he is free to test whatever version of Hypercat or Pyrocat that he choses.

    And this is the last post I plan to make about developers for several months, if ever.

    Sandy

  9. #19

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    buffering and phenolic hydroxides

    Proper buffering is important with phenolic hydroxides, they have a tendancy to oxidize much more quickly at a high ph. This would be consistent with a highly active developer that quickly peters out.
    Since we have a system here that is multiphase (the emulsion is a a solid, the base and reducing agent are in solution) we can only push the speed of development so far.

    One way of getting around this problem may be to try phase transfer catalysts such as Benzyl Trimethyl Ammonium Chloride or Tetra Methyl Ammonium Chloride .

  10. #20
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    Quote Originally Posted by c6h6o3
    Toxicity is the least of my problems with NaOH.

    I don't know what form you buy it in, but in solid form it's extremely caustic and volatile. The chemical burns it will cause may not even be apparent to the victim for quite a few hours, and they can be quite serious.

    Sodium Hydroxide is a substance I simply refuse to have in my house.
    My grandmother made soap using lye and lard. It is used in many drain cleaners. Most of the others use potassium hydroxide. Some even use concentrted sulfuric acid. Clorox is pretty bad stuff. None of it compares with the dangers of walking across a city street, IMOH.

    NaOH is certainly caustic, but I can't see the volatile part. What evaporates from its surface is water.
    Gadget Gainer

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