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  1. #81
    Ian Grant's Avatar
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    Quote Originally Posted by Ryuji View Post
    Ammonium chloride would actually make the image grainier than having nothing at all. It'll give opposite effects to sulfite. You can't just round them all up with a categorical label "silver halide solvent."
    Back in the 1960's around the time Ilford released Perceptol they pulished a datasheet "TECHNICAL INFORMATION SHEET P10 FINE GRAIN DEVELOPMENT" which gave an over view of different approaches to fine grain developers. In this document they advocated adding Ammonium Chloride 40g to 1 litre ID-11 (D76) to give much finer grain. There's a loss of film speed which is halved and the development times need to be doubled.

    This works with most developers. So Mark's right in saying adding Ammonium Chloride would give finer grain, however it would change the characteristics of the developer and in practice Sodium Chloride is used in preference as in Microdol-X and Perceptol.

    Ian

  2. #82

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    Quote Originally Posted by Ian Grant View Post
    Back in the 1960's around the time Ilford released Perceptol they pulished a datasheet "TECHNICAL INFORMATION SHEET P10 FINE GRAIN DEVELOPMENT" which gave an over view of different approaches to fine grain developers. In this document they advocated adding Ammonium Chloride 40g to 1 litre ID-11 (D76) to give much finer grain. There's a loss of film speed which is halved and the development times need to be doubled.

    This works with most developers. So Mark's right in saying adding Ammonium Chloride would give finer grain, however it would change the characteristics of the developer and in practice Sodium Chloride is used in preference as in Microdol-X and Perceptol.
    Ian
    I tried adding 40 g/L Ammonium Chloride to XTOL, and I could see no difference at all. Except that development was slower due to lower pH.
    Likewise, adding Sodium Chloride to XTOL made no difference.
    Except that after adding Sodium Chloride and pouring the developer back and forth a few times developing test-strips, it finally decided to have sudden death after all that abuse.

    I respect XTOL. It seems difficult to improve on it using classic tricks.

    Mark Overton

  3. #83
    Photo Engineer's Avatar
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    I think that you are all looking for a magic bullet to solver your problems of speed, grain and sharpness. Remember that this triad makes up what is essentially a "water balloon" which will burst if you push too hard. Usually, you can only get 2 of the 3 at a time.

    In any event, with the millions put into their budget for new developers, don't you think that Kodak would have solved the problem? Well, they were on their way there when all R&D stopped, and none of the above was the answer. They were going in an entirely different direction.

    And, there is a substitute for Sodium Sulfite that is a good preservative and halide solvent! In fact, I know of 2 solvents, one of which is totally soluble in the organic phase solvents.

    PE

  4. #84
    Ian Grant's Avatar
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    Mark, one problem is modern emulsions are so good that the fine grain is inherrent in the emulsion and different developers have less effect compared to films in the 60's and 70's.

    Xtol already gives finer grain than D76/ID-11 and if you look at Kodak's own comparison chart (see attached) you'll see they show grain only just behind Microdol-X. Now if you tried adding Ammonium or Sodium Chloride to your simplified DS-10 that might be slightly different.

    Ian
    Attached Thumbnails Attached Thumbnails kodak.jpeg  

  5. #85

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    Quote Originally Posted by Ian Grant View Post
    Back in the 1960's around the time Ilford released Perceptol they pulished a datasheet "TECHNICAL INFORMATION SHEET P10 FINE GRAIN DEVELOPMENT" which gave an over view of different approaches to fine grain developers. In this document they advocated adding Ammonium Chloride 40g to 1 litre ID-11 (D76) to give much finer grain. There's a loss of film speed which is halved and the development times need to be doubled.

    This works with most developers. So Mark's right in saying adding Ammonium Chloride would give finer grain, however it would change the characteristics of the developer and in practice Sodium Chloride is used in preference as in Microdol-X and Perceptol.
    Film emulsions from 1960s are pretty different from todays stuff. If you add 40g/L ammonium chloride to ID-11 and develop most pictorial films today, you're more likely to get slightly coarser grains. Same with sodium chloride. I've done several experiments on this topic and abandoned this route early on.

    Generally speaking, it is not very productive to search for a developer that gives better granularity than DS-10 or XTOL. Dimezone-ascorbate developer at pH of 8 to 8.5 range already gives pretty good overall image quality including fine grain. Trying to coerce the film's characteristics by developer formulation even at a loss of speed is not going to be productive. It's much better to formulate the developer to pull the best out of the film. If you need finer grain even at a lower speed, it's far far better to switch to Acros or TMX.

    Also, I would not stretch quoted Ilford statement to "this works with most developers." If you add ammonium chloride to developers with higher pH you get more powerful effects from ammonia base form. You'll get grains like HC-110.

  6. #86
    Ian Grant's Avatar
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    Well adding Sodium Chloride still works for Ilford and Lodak in Microdol-X (what little stocks are left) and Perceptol with modern films.

    I did some tests using Tmax 100 about 3 or 4 years ago adding Sodium Chloride to a developer and it did reduce the grain size slightly, however I'm not interested in any speed or sharpness loss. Ilford also suggested adding Ammonium Chloride to a higher pH developer but I've not tried it myself.

    I'm not advocating the use of Ammonium or Sodium Chloride but it does work with modern emulsions and so shouldn't be dismissed and it may help in Mark's simplified DS10.

    Ian

  7. #87

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    Quote Originally Posted by Photo Engineer View Post
    I think that you are all looking for a magic bullet to solver your problems of speed, grain and sharpness.
    I'm willing to sacrifice a little of XTOL's accutance and speed to improve grain. But I was surprised that I couldn't improve grain. Ryuji just mentioned that he tried the same ideas ... with the same results.

    Quote Originally Posted by Photo Engineer View Post
    And, there is a substitute for Sodium Sulfite that is a good preservative and halide solvent! In fact, I know of 2 solvents, one of which is totally soluble in the organic phase solvents.
    And you're not telling us, so it's probably Kodak-proprietary. Let's see, what could it be? You didn't mention toxicity, so how about... Potassium Cyanide!

    Mark Overton

  8. #88

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    Quote Originally Posted by Ryuji View Post
    Generally speaking, it is not very productive to search for a developer that gives better granularity than DS-10 or XTOL. Dimezone-ascorbate developer at pH of 8 to 8.5 range already gives pretty good overall image quality including fine grain.
    That's what I'm discovering the hard way.

    BTW, I'm using Phenidone instead of Dimezone. And I've read in a couple of postings that Phenidone is a little more active, implying that less should be used. Is that true in your experience? Are there any image-quality differences between Phenidone and Dimezone?

    Thanks,

    Mark Overton

  9. #89
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    Mark;

    Phenidone is less stable in alkali than its two analogs.

    As for the other new ingredients? Well, did you get the secret ingredient of the other developer that you are interested in? Mine are very common in several cases and are actually in use in some developer, just not in combination or proper combination.

    Someday, I will either post it here, or design my own developer to put up for sale.

    PE

  10. #90

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    Quote Originally Posted by albada View Post
    BTW, I'm using Phenidone instead of Dimezone. And I've read in a couple of postings that Phenidone is a little more active, implying that less should be used. Is that true in your experience? Are there any image-quality differences between Phenidone and Dimezone?
    Technically, there are some small differences in developing properties of Phenidone derivatives. There were many compounds tested, both electrochemically and also photographically, and they were published. The best of the best has been so known, but not really used in commercial formulation because of cost and other practical concerns. There are some small differences between Phenidone A and Dimezone S, but the difference is small enough that you can safely ignore it. (there are folks who linger on tiny points but if you get sidetracked by them you'll never achieve big goals! Learning process has a lot to do with knowing what matters and what don't.) The reason why Dimezone S is preferred is that it is stable in alkaline solution whereas Phenidone A isn't. But at pH of 8.2 and for short term keeping, it's not a problem. If you are making a concentrated developer at pH of 10 and people buy stuff many months after manufacturing, yeah you should use Dimezone S definitely.

    Back on fine grain agents. Be very careful when comparing granularity. A lot of people who think they get better grain with Perceptol or Microdol-X with modern film are in fact underdeveloping. That is, they are ok getting lower contrast with these developers than when testing D-76 or ID-11. What they are missing is that if the film is developed to the same contrast index the grain is same or slightly coarser. One can equally underdevelop in DS-10 and get good results as well.

    Halides, ammonia and primary amines are silver halide solvents, but they tend to make bigger grains, at least if you test them in Phenidone-ascorbate type developers.

    Sulfite is more gentle fine grain agent, and I prefer 30-80g/L of it in the working solution of fine grain developers. If you can't use sodium sulfite, you can use potassium salt. Also, you can use sulfur dioxide gas reacted with organic base such as triethanolamine. This is what's done in HC-110, but HC-110 also uses primary and secondary amines, which is also silver halide solvent (see above). That's one of the reasons why HC-110 gives coarse grain. (Also the pH is higher.) But such a combination is susceptible to dichroic fog and other forms of silver stain so there are some tricks. Usually, dihydroxybenzophenones, poly(vinyl pyrrolidone), heterocyclic antifoggant compounds, etc., are used in high solvent developers, such as HC-110, Microdol-X, etc. You probably need some quantity of PVP to be effective, but other compounds are used in such a small quantities that they usually don't appear in MSDS. I tried all of the above compounds in DS-10 and its later variants in attempt to increase solvent contents and still get even better image quality. Conclusion: they didn't harm but did not help either, at least in DS-10.



 

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