Improved version of DS-10 by Ryuji Suzuki?

[Ryuji]

Why would a long time in a sulfite-rich solution, in and of itself increase graininess? That seems odd, unless what you're seeing is simply more development taking place due to the developing agents being better preserved by the higher sulfite level, which would indeed increase graininess. But that's not "direct" action by the sulfite.

This is a very good and relevant question.

Some people here seem to jump to fallacious conclusions... many equate sulfite with solvent, solvent with physical development, physical development with fine grain effects, where each association here is problematic. For example, sulfite does a number of other things than dissolving silver halides. Solvent effect does not entail in physical development. Physical development may make larger or finer grain, often within the same emulsion and same developer. So, making a grand fallacy of sulfite = fine grain is misleading, but some seem to be trapped with it.

If the reported experiment was done very carefully, the most plausible explanation of the result is that sulfite acted as a mild “disinhibitor” or accelerator of development process, and this is well known.

 

[Rudeofus]

Sulfite is also your preservative to a certain extent, extending the life of the developer.

That's a nice property of sulfite but I assume Mark mixes his soups as he uses them, so preservation seems less of an issue here.

Oxidized ascorbates are not regenerated by sulfite. The oxidation reaction is quite complex depending on the condition, but the reaction pathways that matter in this context, the mechanism is very different from that of hydroquinone

Oops. Read too many articles on superadditivity and got that mixed up apparently. So much for "learn photo chemistry in 24 hours"

Yesterday, Rudeofus mentioned that SMAP is restrictive. True, but for a concentrate, I'm not restricting myself to metaborate-ascorbic-phenidone. For example, Boric acid is a worthy chemical for a concentrate, and buffers well with metaborate. TEA is another. But I'm finding that one can accomplish surprising things with only the four SMAP components, so I'm using them as my baseline for experiments.

The biggest advantage of restricted choice of ingredients is that the number of experiments doesn't go through the roof, so there's a good chance we as amateurs can even reach the optimum of what is possible with these ingredients. But lets not forget that Kodak could afford lots of engineers, lots of experiments and had lots of exotic compounds at hand so there is a good chance that Xtol will always be superior to SMAP except for a few special cases. The original question you asked about your SMAP sounded like "I beat Xtol in grain size and speed, how come it's still better in sharpness?".

Instead of beating Xtol in all respects we could focus on beating it in a few relevant parameters so we can mix and match dev depending on application. I would love to create a set of 10 recipes, all using the same set of easy to get ingredients only in different concentrations and which would cover the whole speed/grain/acutance triangle. Current recipe collections read like books about cocktail mixing, where you need 10 different ingredients for 3 cocktails and 20 if you want to mix 6 of them.

There are others reasons such as the fact that solvent developers can change edge effects and change visual contrast thereby subtly altering the visual appearance of grain making it appear worse.

Yes to that. Let's not forget that the grain we observe is not the individual silver grains but a superposition of them. A lot of things have an effect on visual grain, actual silver grain size is only one of them.

 

[Keith Tapscott.]

Oxidized ascorbates are not regenerated by sulfite. The oxidation reaction is quite complex depending on the condition, but the reaction pathways that matter in this context, the mechanism is very different from that of hydroquinone.



That’s right. When I look back my work in DS-10, which was intended to err slightly on the safer side with the knowledge I had at that time, knowing that pH of 8.0 was a slightly risky choice, I can simplify it a bit now, but I can only remove three ingredients (but must add one new agent) without sacrificing the stability/reliability of the developer.

Would you reveal your formula for those interested in trying it?

 

[Ryuji]

Would you reveal your formula for those interested in trying it?

I might be cynical here, but I'm not into publishing every little variants of so many developers I made and tried and used just because they are different. They made the same photographic effects for all practical purposes.

You might want to go to a Hong Kong restaurant, and ask your server, what's the difference between yesterday's and today's daily soup?

Then do you see the title of this thread? "Improved version of DS-10 by Ryuji Suzuki?" You don't want to see me if the title did not end with a question mark.

But one thing I can reveal now is that, the reason why I used that much TEA (and would've used more if I felt like it) and salicylic and boric acids was to increase the stability of the developer. I am ok with less of these ingredients, and zero salicylic and boric acids, only because I have a much more powerful developer stabilizer (which was used for Tektol developers after the packaging changed).

 

[Ryuji]

Instead of beating Xtol in all respects we could focus on beating it in a few relevant parameters so we can mix and match dev depending on application. I would love to create a set of 10 recipes, all using the same set of easy to get ingredients only in different concentrations and which would cover the whole speed/grain/acutance triangle.

That's what I've been saying for years... since when I was using precursors to DS-1 and DS-2.

 

[Gerald C Koch]

May I recommend the following article as it explains many of the design factors concerning the formulation of Xtol. This article may be hard to find but is worth reading. It is no longer on the PT website but copies of it do exist on the web.

The Genesis of Xtol
Dick Dickerson and Silvia Zawadski
Photo Techniques Vol 20, #5

 

[albada]

I might be cynical here, but I'm not into publishing every little variants of so many developers I made and tried and used just because they are different.

On the other hand, publishing a formula allows for community-review and community-testing, which helps catch flaws. In the software-community, this is called "open-sourcing", and it's popular -- for good reason.

the reason why I used that much TEA (and would've used more if I felt like it) and salicylic and boric acids was to increase the stability of the developer

I've never heard that boric acid is a stabilizer. Is that merely because it's an acid, or is there something else about it that helps stabilize?

Mark Overton

 

[Ryuji]

On the other hand, publishing a formula allows for community-review and community-testing, which helps catch flaws. In the software-community, this is called "open-sourcing", and it's popular -- for good reason.

On the internet you can find a lot of competent software engineers. That is not the case on this forum.

I've never heard that boric acid is a stabilizer. Is that merely because it's an acid, or is there something else about it that helps stabilize?

I didn't say boric acid is a stabilizer. Triethanolamine and salicylic acid are. In many practical chemical choices one has to make, one just can't change one thing without balancing other factors.

 

[Rudeofus]

On the internet you can find a lot of competent software engineers. That is not the case on this forum.

Don't underestimate the number of competent software engineers in this forum


@Mark: The original formulas for DS-10 and DS-12 were published a long time ago, and as far as I have understood the main issues Ryuji has dealt with since then were longevity and manufacturability while keeping the dev properties the same. For all open sourcerers amongst the home brew crowd we have the raw source ingredients, but we won't get the nice packaging for free. Remember, Ryuji made several attempts at commercializing his devs in the past. Rather than screaming that everything should be free for us we should be grateful that he helps us here in the forum.

 

[Ryuji]

For record, DS-10 and DS-12 were not designed with manufacturability in mind. I was still focusing on making the developer stable for practical routine processing.

I did not publish any formula that was specifically made with manufacturability in the scope. The first generation Tektol developers were a one-step forward from DS-14, but the second generation Tektols were further improved. But then Tektol is no more. One reason why I don't publish the formula for Tektols in part has to do with the ingredient (developer stabilizer) not available from anywhere but Silvergrain, but chemical sales is not my business... When Silvergrain chemicals were offered for sale, I actually prepared the stabilizer additive and shipped it with instruction to the factory under nondisclosure agreement. The entire formula was under the scope of NDA but there was no better way to do this. Suppose the darkroom chemical market is 7000x larger than what it is today, and if it makes sense to do Silvergrain chemical again, I'd actually set up my own mini-plant. While I accumulated a lot of insight and know-how as to how to prepare ascorbate developers with minimum of aerial oxidation during manufacturing, I think the factory people didn't like to be told what to do, so a lot of my knowledge wasn't utilized effectively. Believe or not, when factories prepare developer concentrates, the solution is heated, stirred and poured for hours from start to finish, and many of the mixing apparatuses are made from stainless steel, so there are a lot of things that would be ok with hydroquinone developers but not with ascorbate developers.

A lot of people don't realize, but if you pour hot water in a stainless steel vessel, a trace amount of iron goes into the water. This level of iron is significant for unprotected ascorbate solution. The second generation Tektol had a stabilizer that deals with this problem. I use the same technique for my film developer, so that I have no concern using stainless reels and tanks (which are made from lower grade stainless steel than chemical mixing vessels).

 

[Tronds]

Don't underestimate the number of competent software engineers in this forum

Yes, there are several of them, and they know problem solving and testing.

 

[Ryuji]

Yes, there are several of them, and they know problem solving and testing.

How many people here actually have experience in debugging misconceptions, gross oversimplifications, and other errors in popular darkroom "chemistry" books?
How many people here actually identified a problem, formed a design objective and offered practical solutions to it through a systematic approach?
How many people here have a paper on photographic chemistry published in a peer reviewed academic journal?

There used to be a couple, but they've moved on.

 

[Tronds]

How many people here actually have experience in debugging misconceptions, gross oversimplifications, and other errors in popular darkroom "chemistry" books?
How many people here actually identified a problem, formed a design objective and offered practical solutions to it through a systematic approach?
How many people here have a paper on photographic chemistry published in a peer reviewed academic journal?

There used to be a couple, but they've moved on.

Soooo, because there are people here actually have experience in debugging misconceptions, gross oversimplifications, and other errors in popular darkroom "chemistry" books, other trained people don't understand anything, and just speaks nonsense?

There are infact several people that have read some more than popular darkroom "chemistry" books, but writing a comment here is not accepted.
Doing so starts the "newbie bashing".

Well, that's ok. There are several people that have stopped writing constructive postings here beacause of this.
Many have moved on because of the hostile anvironment here.
I for sure won't discuss my work in here. Neither will I try to help when someone asks for help with a problem.
The forum Gods have to step up and offer help, IF they want, and isn't in the bashing mode.

 

[Photo Engineer]

Interestingly enough, between APUG and Photo Net there are about 4 Kodak photo engineers making comments. They are still here, and still plod away. Mix in with that the fact that my original Blix formula went on sale by Kodak in 1970 and is still on sale in slightly modified form today. The corresponding color developer went on sale in 1970 as well and sold until the RA 4 process came into use.

The Fomulary's Liquidol and TF-5 have been and remain on sale for our B&W friends, and more developers and fixers are in the pipeline just waiting for completion of tests.

I was one of the "peers" who reviewed Grant Haist's two volume set, and have had many publications and patents as have the others who contribute here.

I also led a group of software engineers in developing the Kodak Emulsion Design and Scaling System.

So, I would say you have a pretty fair chance of getting a usable answer from me or one of my friends. If not, I can always consult with them and get back with an answer. I have tried to do that for Mark and others.

The number of highly qualified people posting here is greater than one might expect and they are willing to share information unless it is proprietary and they are bound by an outside NDA. A self imposed NDA is at the discretion of the originator, of course.

PE

 

[analog what is that?]

...

 

[analog what is that?]

,,,,,,,

 

[Gerald C Koch]

It's probably best not to make any generalities about APUG. I think that the contributers are a diversified group. What binds them together is a love of photography. I don't usually toot my own horn as that is not my style. Very briefly for the record I have a BS in chemistry, an MS in nuclear chemistry, and a BS in computer programming. For a number of years I worked at the Kennedy Space Center.

Jerry

 

[Kirk Keyes]

Sweet, Jerry! What did you do there?

The only thing I've done at KSC is visit and buy t-shirts!

 

[albada]

I might need a new pH probe. A few questions:

1. What brand/model would you recommend for a price of around US$60?
2. Should I pay extra for a high-salinity/high-alkalinity probe?
3. Is it normal for a probe to need a few minutes to acclimate to a high sulfite solution?

My Hanna pHEP-5 probably needs a new probe. It has always needed about 4 minutes to acclimate to a sulfite solution. Once acclimated, it responded quickly to changes in pH. But this evening, the pH started dropping as I was watching it. Adding alkali failed to raise pH. Due to Hanna's poor packaging, this probe was dry when I got it a month ago, so I expected it to be a short-liver.

Based on my Internet research, I discovered that all pH probes have the same electrical behavior at the connector. So I figure I'll hack a BNC-connector onto my pHEP-5 meter, and attach a better probe to it. Does anyone know of a reason this will not work?

TIA!

BTW, I'm a computer science geek. But in college, I almost became an EE (electrical engineer), and I've tinkered with electronics all my life, so I know enough about electronics that companies have me work with their EEs, since I'm one of the few programmers around who can read circuit-diagrams and talk EE-lingo. EEs and I get along great.

Mark Overton

 

[Ryuji]

It's probably best not to make any generalities about APUG. I think that the contributers are a diversified group. What binds them together is a love of photography.

I take this as your reaction to my previous post, which I think was overstated my sentiment, but I hope people understand that I spent a LOT of time posting information online, this site and several other places before APUG started. But I was seriously troubled by several people on this website, who demanded information as if they were entitled to anything and everything I know or figured out. I simply don’t shouldn’t be obligated to share information when I know from experience that I’ll be facing a lot of questions or requests that I can’t help. That “open source” phrase, while I used it myself in relation to darkroom chemistry, was also previously used by some in the very context above and I personally don’t need to see that again. When people say whatver to justify pressuring me to share information I get irritated!!!

 

[Ryuji]

I might need a new pH probe. A few questions:

1. What brand/model would you recommend for a price of around US$60?
2. Should I pay extra for a high-salinity/high-alkalinity probe?
3. Is it normal for a probe to need a few minutes to acclimate to a high sulfite solution?

My Hanna pHEP-5 probably needs a new probe. It has always needed about 4 minutes to acclimate to a sulfite solution. Once acclimated, it responded quickly to changes in pH. But this evening, the pH started dropping as I was watching it. Adding alkali failed to raise pH. Due to Hanna's poor packaging, this probe was dry when I got it a month ago, so I expected it to be a short-liver.

What you described is one of the typical symptoms of clogged or chemically deteriorated reference electrode junction.

You should get a double junction and refillable probe. Replace the fill solution every time you use the probe. It is usually best to replace the fill solution at the end of shift.

High alkalinity electrodes use slightly different glass membrane, which is important at pH 13 and above. They are not really needed for photographic applications. The place that gets shot in photographic applications is the reference junction.

Usually, high salt solutions are faster to settle/stabilize reading. If your reading doesn’t stabilize in a few minutes at 25C, the reference electrode is the first place to check.

There are two common causes for unstable reading, when the electrode is perfectly normal. One is low temperature. Measurement at 20C is not very good idea for this reason. This 5C difference is big for the glass membrane. Another cause is when you clean the electrode. If you use brush or other mechanical means to clean the glass membrane, forget it. Put the electrode in 3M KCl solution and go for lunch. You won’t be making any meaningful reading for about 2 hours. You can't even calibrate the system. This is yet another reason why it is best to clean the electrode at the end of each shift.

Another possible place to go wrong is moisture or conductance leak. The input impedance of the pH meter amplifier is REALLY high. Slight moisture can cause significant leakage that affects the sensitivity "slope" of the electrode. This is common with cheap pH "tester" type devices. I remember throwing away a few of those testers for this. (But all of them used gel filled reference junction, that gets killed by the test solution in a few weeks anyway.)

The least expensive electrode I know suitable for photographic work is Hanna HI-1333. It's cheap because Hanna sells it as "student lab grade" or "fish tank" or "field monitoring" use and not really rated for analytical lab use. At least that's what Hanna tech support told me years ago. That's good enough for routine darkroom use. When I had a deep tank line for film, and slot processor set up for prints, HI-1333 was used in the processing station to monitor the health of those solutions, but it never failed on me unexpectedly. I think I replaced the electrode only once in a 10 year period (but I did take very good care of it. most people kill the electrode in less than 2 years.) and the second electrode is still alive (I just took it out of the storage).

 

[Ryuji]

Based on my Internet research, I discovered that all pH probes have the same electrical behavior at the connector. So I figure I'll hack a BNC-connector onto my pHEP-5 meter, and attach a better probe to it. Does anyone know of a reason this will not work?

You need to be very careful in choosing low leakage BNC connectors, wiring and whatever connector used in your pHEP-5 (Molex maybe?). Those lines have to be VERY high impedance (on the order of hundreds of megohms) and well shielded from noise. The bandwidth of the amp is very low, so you mostly worry about low frequency inductive noise. Also be very careful about each connection. You want to minimize flicker noise (a.k.a. 1/f noise or pink noise), which will appear as the drift in the reading. Usually, you get most of the noise from the electrode itself but just try not to add any.

BNC connectors are usually designed for constant RF impedance, but that actually doesn't matter for pH measurement. What matters for this is leakage.

 

[Ian Grant]

How many people here actually have experience in debugging misconceptions, gross oversimplifications, and other errors in popular darkroom "chemistry" books?
How many people here actually identified a problem, formed a design objective and offered practical solutions to it through a systematic approach?
How many people here have a paper on photographic chemistry published in a peer reviewed academic journal?

There used to be a couple, but they've moved on.

I seem to remember a section on your own website based around a misprint in a US book of amount of Bromide in the ID-78 formula, and despite the error being pointed out to you many times over a few years you never corrected it even though you quoted elsewhere from two primary sources with the correct version of the formula (one an Ilford Manual, the other a book by an Ilford chemist - LFA Mason). Hardly good academic practice.

One problem with many of the Darkroom "Chemistry" books published in the US was they were riddled with errors and mistakes because nearly all the formulae were taken from copies of he Photo Lab Index (where the mistakes were first made) andnot original primary sources. Steve Anchells 3rd Edition of "The Darkroom Coobook" was the first book to be cross-checked where ever possible with manufacturers published data and as a consequence many formulae were corrected.

A classic example of the misprints is the Pyrocatechin compensating formula attributed to Hans Windish (he doesn't clain it as his own in his books) this was published correctly in Jacobson's Devloping (1st Edition) as well as in Windisch's own book, however a BJP Almanac in the late 1940's or early 50's publishes a US version of the formula where the qunatities of Pyrocatechin and Sulphite have been transposed, this version happened to work as well although differently.

How many people here actually identified a problem, formed a design objective and offered practical solutions to it through a systematic approach?

Quite a number of us actually, however often work could not be published due to commercial secrecy.

Ian

 

[Photo Engineer]

Mark;

I have had 3 Hanna electrodes, and none have given me any problems. I used many at work as well. We never used "special" electrodes for high salt or high pH and always got good results.

The symptom you describe could also be due to a cracked glass bulb on the electrode. This would also give the result that the electrode would eventually empty of all solution. This has been my experience when having problems. A broken electrode.

PE

 

[Gerald C Koch]

I take this as your reaction to my previous post, ...

Hi Ryugi,

My post was only to caution everyone that we really know very little about others that post on APUG and shouldn't make generalities about their knowledge and qualifications. In my own experience I have said things which I soon regretted. Now commuicating with people in this wonderful age on a text only basis is difficult. Things that are easily understood verbally are often misunderstood as text.

Jerry