Improved version of DS-10 by Ryuji Suzuki?

[Alan Johnson]

Yes, good to read your posts again Ryuji.
I wonder if the improved fine grain developer you made might be considered in any respects better than Xtol.

 

[Ian Grant]

Kodak supplied the developing agent paraminophenol as the oxalate salt under the tradename kodelon. Therefore their developers would naturally use this salt rather than the hydrochloride. We should not jump to the conclusion that there is any other reason for DK-93 containing a small amount of oxalate.

Oxalic acid is a poorer chelating agent than salicylic acid. In addition we do not know whether it will inhibit oxidation or enhance it.

p-Aminophenol Hydrochloride was also sold by Eastman Kodak as Kodelon and depending on when/where a formula was published may well say p-Aminophenol Hydrochlride or Kodelon.

Mees had worked on p-Amininophenol developers while at Wratten & Wainwright and much of Kodak's work on them was carried out at Kodak Ltd's Harrow Research facility. Kodak UK marketed Kodinol which like M&B Azol, Ilford Certinal etc was a direct competitor for Agfa's Rodinal.

So we need to be careful assuming the possible role of Oxalate in a developer like DK-93 which Kodak published as using Kodelon and elsewhere p-Aminophenol Hydrochloride.

Ian

 

[Ian Grant]

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

 

[albada]

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

 

[Photo Engineer]

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

 

[Ian Grant]

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

 

[Ryuji]

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.

 

[Ian Grant]

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

 

[albada]

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.

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

 

[albada]

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

 

[Photo Engineer]

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

 

[Ryuji]

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.

 

[Alan Johnson]

The Europeans have gone down different routes, Xtol is not necessarily end of story.
Here can be found the MSDS for Rollei RLS which contains ammonium chloride and some Spur developers using thiocyanate:
Dead Link Removed

 

[albada]

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.

Obviously, we encourage you to post the ingredients here. Perhaps you could patent their use to prevent others from using them in a developer. That would both publish the knowledge so it won't be lost, and could give you an income from a product.

BTW, I discovered your full name, and did a patent-search on you via www.google.com/patents. Wow!

Mark Overton

 

[albada]

Two questions for Ryuji about DS-10 (I hope he's still watching this long thread):

1. Could the Dimezone and Ascorbic acid be kept in a separate concentrate in propylene glycol? I would hope that both concentrate and working solution (containing no developers) would last at least a year. Before using, some concentrate would be added to working solution for one-shot use.

2. If the answer to question 1 is "yes", then are TEA and Salicylic acid still needed? Your older posts indicate they are used to chelate iron to protect the developers to improve storage-life. Does the TEA affect image-quality?

Thanks,

Mark Overton

 

[Photo Engineer]

Mark;

My neither my work nor my name are secrets here and on Photo Net. And, my work is not unusual for EK researchers. I have many Defensive Publications and Research Disclosures of materials in addition to the Patents. If you search there, you will see some of the ingredients mentioned!

PE

 

[albada]

Mark;
My neither my work nor my name are secrets here and on Photo Net. And, my work is not unusual for EK researchers. I have many Defensive Publications and Research Disclosures of materials in addition to the Patents. If you search there, you will see some of the ingredients mentioned!

Ron,

My copy of Mees arrived today. That's an amazing compendium of knowledge, even more so than Mason. Among many other developers, he describes ferric-EDTA. I didn't know that any EDTA-compound would develop. Interesting. I thought EDTA was used mainly as a chelating agent and as a halide solvent.

Anyway, many if not most defense research disclosures are done in ResearchDisclosure.com. I have published in them myself at my prior job. But a subscription costs $1490 annually, so I won't be doing that. I wish they had a cheap personal-subscription program.
That leaves patents. I'll look through yours. You can PM me the ingredients and I'll promise not to tell anyone!

Mark

 

[Photo Engineer]

Mark, read the patents.

PE

 

[Gerald C Koch]

In the very early days of photography ferrous sulfate was used as a developing agent. Oxalic acid was used as the chelating agent. This developing agent produced almost no fog but didn't completely develop the latent image causing some speed loss.

 

[Photo Engineer]

Jerry;

IIRC,the prevalence of this developer back then led some manufacturers and home coaters to compensate with high silver "silver rich" coatings to help alleviate the problem thus placing another rung in the ladder leading to the mythos surrounding "silver rich" products.

I had completely forgotten about this until your post.

PE

 

[Gerald C Koch]

For anyone who might want to try using ferrous sulfate the following is from Neblette's book.

As a developer ferrous oxalate is noteworthy for its fog-free, pure black silver deposit. It does not, however, fully develop the latent image and greater exposure is necessary than with the more energetic organic developers. This is of no concern in the case of papers and transparencies for which it is well adapted on account of its freedon from stain and fog and the clean, neutral black image.

Soution A:
Ferrous sulfate 330 g
Sulfutic acid, conc 1.0 ml
Water to make 1.0 l

Solution B:
Potassium oxalate 330 g
Hot water to make 1.0 l

For use, take 1 part of A and 4 parts of B.

Only the highest grade of ferrous sulfate should be used and this should be fresh. The stock solution will keep for only one or two days.

 

[Gerald C Koch]

Ron,

I came across this formula many years ago and actually tried it out. It does what Neblette says and the image really is a pure neutral black. I mentioned it because the iron EDTA developer seemed to be doing something similar although the chelating agent was different.

Jerry

 

[albada]

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.

I searched through the patents, and here are the silver halide complexing agents I noticed which could be considered organic (containing carbon):

Thiourea (an "organosulfur") (plus Phenyl-, Allyl-, Ethylene-)
Sodium/potassium/ammonium Thiocyanate
3,6-Dithia-1,8-octanediol (CAS 5244-34-8) (many others in this family, but nobody's selling them)
ethylene-bis-thioglycolic acid (or GDMA) (CAS 123-81-9) (many others in this family, but nobody's selling them)

​

Thiourea came up repeatedly. Other searching shows it to be a powerful solvent (only .5-1 g/L needed). Are there any disadvantages to this, such as skin contact dermatisis mentioned in an MSDS? I'm hoping it'll dissolve in PG.
The Thiocyantes also are common. They contain carbon, but that doesn't mean they'll dissolve in PG, as I found out with Sodium bicarbonate. Comments about Thiocyanates?
How strong a solvent are 3,6-Dithia... and ethylene-bis-...? The 3,6 is easily purchasable for about $33 for 25g, so it's tempting if it's a strong solvent and PG-soluble and not too toxic.

Sorry about so many questions in one post. I'm learning.
Thanks!

Mark Overton

 

[Gerald C Koch]

Several more compounds are listed in Grant Haist's book "The Monobath Manual." Anyone interested in photographic chemistry should have this book as it contains quite a bit of information for its size.

Ionic compounds such as sodium bicarbonate are not usually soluble in non-ionic solvents such as glycols. Kodak uses a mixture of TEA and DEA to provide the proper pH for HC-110. They also use the addition product of DEA and sulfur dioxide to replace sodium sulfite used in conventional water based developers.

 

[Photo Engineer]

Mark;

You are looking in the wrong places. You want developer stabilizers, not silver halide solvents! At least in this context. As for silver halide solvents, you just have to experiment as the level is very much a function of the developer formulation itself. This is grinding plodding work that involves the use of what is called a factorial experiment.

PE