DK.50, Harvey's 777 and the phenomenon of developer ripening

[Pixophrenic]

I think many of you would agree that DK.50 is one of the benchmark developers, and some still use it today. So, re-reading Crawley's famous series on FX developers, I found his version that he called "diluted DK.50" and presented it as a non-solvent developer. It comes at the end of the rather long list of FXs, and this intrigued me, because from the rest of his articles you would expect this developer to produce grain the size of a golf ball. I made a small portion of it, as outlined by Crawley, which is (per liter): metol 0.5 g, hydroquinone 0.5 g, sodium sulfite 6 g, potassium bromide 0.125 g. At this point I measured the pH and it was close to 7. Since I only had a "reconstructed kodalk" made in solution from borax and sodium hydroxide on hand, I started adding it piece wise, measuring the pH in the process. It came as a revelation that only 1/3 of the required volume (~3.5 g) was needed to reach pH 10. However, I proceeded to add the rest and re-measured the pH. It was a little higher but still close to 10. Then I "ripened" it by developing an entire fogged film in 0.5 L for 6 minutes. I then started to develop clips with exposure-bracketed images in the ripened portion to determine the time for box speed, which was eventually found to be 9 min at 20 C for Kentmere 100. The negatives were very nice, normal contrast and fine grained, and overall looking great, judging from the included Stouffer wedge shot on a light box.

Surprised by this outcome, I started reading other threads about DK.50 and eventually came across one posted by user "nworth", where a two-solution concentrate was cited as a "sharpness" developer, reportedly published in BJP for use with miniature film, and supposed to be used one-shot. Solution A was exactly a 5X concentrate of what is cited above, and solution B was 5% sodium metaborate. Its composition was thus identical to Crawley's version when diluted 1:1:3 with water. There is also a post by Gerald Koch to the same effect but a different way of preparing stocks. So, this diluted DK.50 contains 10 g metaborate per liter. Imagine my surprise, when I found (at Digital Truth) that "tank developer" DK.50 also contains 10 g metaborate per liter, but it is used at full strength and is supposed to be "ripened" as initially it is considered too contrasty. Now, pH of my ripened developer is still 10, so even such extreme ripening as I did does not lower the pH. IMHO it would make more sense, if instead of ripening, one would just add less metaborate so as to achieve pH 9, because there is no point in having this much metaborate in a developer claimed to be used one-shot. However, since ripening does not significantly lower the pH, it is not the factor that "mellows" the developer. Could one "simulate" the ripening process by adding chemicals that dissolve silver halide AND form a stable complex with silver? There are quite a few, but most are not in the current PF repertoire.
A later note: Looking up the Jacobsons' book, 18th edition, I found yet another version of DK.50, this time as a tank developer which is exactly 2.5 times more concentrated than the one cited above, except that kodalk is still at 10 g/L. Is this how different authors tried to guess the formula that Kodak did not disclose?

You know why I am asking this: I am looking at a legendary formula like Harvey's 777 and trying to understand how to reproduce its "ripening" without the associated voodoo (no offense intended). Isn't it actually a metol-glycin developer, in itself quite contrasty, with two silver halide solvent(s) added? If so, there could be another magical solution without the PPD.

 

[Gerald C Koch]

You know why I am asking this: I am looking at a legendary formula like Harvey's 777 and trying to understand how to reproduce its "ripening" without the associated voodoo (no offense intended). Isn't it actually a metol-glycin developer, in itself quite contrasty, with two silver halide solvent(s) added? If so, there could be another magical solution without the PPD.

Interesting how you can do this as the formula for Harvey's Pamthermic has never bee revealed.

DK-50 diluted 1+4 with the metaborate concentration raised bach to its original concentrations is an acutence developer. It will not produce negatives similar to the Harvey formula.

 

[Pixophrenic]

Interesting how you can do this as the formula for Harvey's Pamthermic has never bee revealed.

DK-50 diluted 1+4 with the metaborate concentration raised bach to its original concentrations is an acutence developer. It will not produce negatives similar to the Harvey formula.

Modest acutance is typically generated by low concentration of metol or glycin, working at a relatively high pH. It is in a sense "portable", that is adding a certain amount of metol to an otherwise "unacute" second slow working developing agent at high pH makes the mix acute. To the best of my knowledge, grain always increases but depending on the film, by not much. BTW, I posted Rudolf Jarai developer to the resource, which is a lesser known example, which I would recommend everybody to try out on their favorite film. However, I'd rather not see this thread develop into this direction. I am more interested in "ripening" which is common to both developers listed in the title. I am, of course, looking at what they think 777 is. Or Edwal 12, which appears to be related but no cigar. So, it occurred to me that the magic comes from something that is not initially in the formula, that have to be produced by "ripening". So, the actual question is what can be produced by ripening that alters the developer kinetics? I think some sort of soluble silver complex. Finally, if the development time and a list of developing agents is known in a formula, it is a far less complicated task to find out the quantities. For example, since metol and glycin are acidic and PPD is weakly alkaline, if this formula indeed runs initially on sulfite alone, it dictates the balance between the three developing agents. Metol must be the driver. Furthermore given that glycin is much slower acting than metol at the same pH, it is kind of doubtful that they are present in the same amount and that no external alkali was added during mixing. Then if anyone cold tell me the pH of the commercial 777 and whether it drifts with ripening, this also greatly reduces the number of choices. Anyway, seems like an interesting challenge after all those M, MQ, PQ, DQ and ascorbate developers have been tried.

 

[Anon Ymous]

Developers containing Hydroquinone may end up having a Hydroquinone Monosulfonate salt after use. This is produced by the reaction of quinone (a Hydroquinone oxidation product) with sulfite and is a developing agent, much less active than Hydroquinone. The release of halides (bromide, iodide) during development can also alter developer characteristics if the original formula doesn't have any in it, like D76.

 

[Pixophrenic]

Developers containing Hydroquinone may end up having a Hydroquinone Monosulfonate salt after use. This is produced by the reaction of quinone (a Hydroquinone oxidation product) with sulfite and is a developing agent, much less active than Hydroquinone. The release of halides (bromide, iodide) during development can also alter developer characteristics if the original formula doesn't have any in it, like D76.

That is all true, but it is not all. D-76, especially replenished, becomes laden with silver, some of which is in solution, and that should contribute to its properties. It was also mentioned that some added a little of spent developer to the new batch, which is equivalent to ripening.

 

[Alan Johnson]

https://www.photo.net/discuss/threads/ripened-developers.96737/
Possibly bromide build-up may inhibit the development reaction AgBr + e -> Ag + Br-

 

[Murray Kelly]

You have said you are not particularly interested in using the DK-50 but to raise a point, if you were aiming at pH9 it might be better to use borax instead of metaborate. To dilute metaborate to give a pH of that range one would risk losing buffer capability.

 

[Pixophrenic]

https://www.photo.net/discuss/threads/ripened-developers.96737/
Possibly bromide build-up may inhibit the development reaction AgBr + e -> Ag + Br-

Thank you, Alan, for the link. Buildup of bromide is certainly a contributing factor. However, examining the DK.50 replenisher, one can see that the components of the original solution are spent at a different rate. Specifically, DK50R has twice the amount of metol but 4x the amount of hydroquinone relative to the main formula, and 4X the amount of Kodalk. which means that during ripening metol is spent slower than hydroquinone, and buffering capacity is decreased, which would be expected to make the developer less contrasty, and while it already has accumulated some bromide, we actually arrive at a different formula. The suggestion of the metallic silver complex present, is, however, entirely left out. In a developer containing PPD or OPD the situation is different as during development a substantial amount of silver goes into solution during ripening, in addition to bromide accumulation. In my experience, PPD derivatives are very sensitive to bromide, so adding it by way of ripening is conceivably a finer tuned process. A facility like Bluegrass has a capability to mix the developer, pre-ripen it (load with some silver) and then pulverise for sale. I am not saying they do it, but it is one thing a normal person would not be able to do, hence "close but no cigar".

 

[Pixophrenic]

You have said you are not particularly interested in using the DK-50 but to raise a point, if you were aiming at pH9 it might be better to use borax instead of metaborate. To dilute metaborate to give a pH of that range one would risk losing buffer capability.

This is a valid point, but I am suggesting exactly that for one-shot use losing some buffering capacity may not be a problem. Saves a lot of kodalk. DK.50, replenished, as tank developer is an entirely different story.

 

[Alan Johnson]

One theory is that metol is adsorbed on the grain surface and two reactions occur to provide electrons to Ag Br, one involves the oxidation of metol and in the other the adsobed metol just passes electrons from hydroquinone.If this is so, the relative rates of these reactions would determine the amounts of metol and hydroquinone in the replenisher.

 

[Pixophrenic]

One theory is that metol is adsorbed on the grain surface and two reactions occur to provide electrons to Ag Br, one involves the oxidation of metol and in the other the adsobed metol just passes electrons from hydroquinone.If this is so, the relative rates of these reactions would determine the amounts of metol and hydroquinone in the replenisher.

So one of these reactions oxidizes hydroquinone and the other metol and the first of these is faster, and both rates are also pH dependent. One has to know if different MQ developers of the "classic" category that have different relative ratios of replenishing metol and hydroquinone were actually "scientifically" formulated" or by trial and error. With all due respect, I do not see how going on the molecular level would help here. I understand though, that by "violating" diluted DK.50 with a whole fogged film I may have created a different developer.

 

[Gerald C Koch]

To use DK-50 1+4 ass an acutence developer you need to keep metaborate as the alkali and maintain its original concentration. This requires using a metaborate solution as the dilutant rather than plain water. Thus the original pH of Dk-50 undiluted is maintained. I've used it this way several times and it works very well producing acutrence similar to the Beutler formula..

 

[John51]

I read of those using D76 one shot having to bin the last of it because it went off and then there are anecdotes of a film lab with years old D76 complete with sludge at the bottom.

How come the one shot user has to bin D76 while the D76 in the film lab keeps on trucking?

 

[MattKing]

How come the one shot user has to bin D76 while the D76 in the film lab keeps on trucking?

Labs used D76 in a replenishment regime - for each 8x10 (or equivalent) a certain amount of old developer was removed, and a certain amount of new developer replenisher was added. The developer replenisher was similar to the basic D-76, but not identical.
D-76 replenisher is no longer made by Kodak, but modern developers like X-Tol and T-Max RS are designed for self-replenishing - the developer itself serves as its own replenisher.

 

[Alan Johnson]

The suggestion of the metallic silver complex present, is, however, entirely left out. In a developer containing PPD or OPD the situation is different as during development a substantial amount of silver goes into solution during ripening, in addition to bromide accumulation. In my experience, PPD derivatives are very sensitive to bromide, so adding it by way of ripening is conceivably a finer tuned process. A facility like Bluegrass has a capability to mix the developer, pre-ripen it (load with some silver) and then pulverise for sale. I am not saying they do it, but it is one thing a normal person would not be able to do, hence "close but no cigar".

In ripening it appears that bromide build-up is involved always, Is it the case that with some developers redeposition of silver occurs? Anything else in ripening?

 

[Pixophrenic]

In ripening it appears that bromide build-up is involved always, Is it the case that with some developers redeposition of silver occurs? Anything else in ripening?

Labs used D76 in a replenishment regime - for each 8x10 (or equivalent) a certain amount of old developer was removed, and a certain amount of new developer replenisher was added. The developer replenisher was similar to the basic D-76, but not identical.
D-76 replenisher is no longer made by Kodak, but modern developers like X-Tol and T-Max RS are designed for self-replenishing - the developer itself serves as its own replenisher.

In my book, Jacobsons "Developing" 18th edition, p. 206 there are both D-76 and replenisher formulas, with the replenisher having 10X the amount of borax as the developer. Is this a typo?
.

 

[Pixophrenic]

In ripening it appears that bromide build-up is involved always, Is it the case that with some developers redeposition of silver occurs? Anything else in ripening?

I think redeposition of silver definitely occurs in solvent developers, but I am not sure if it does in a general case. Today at trying a new "acutance" recipe I saw for the first time the developer turning vivid green after use. This was essentially Rudolf Jarai formula I put in the resource, but metol substituted for by glycin and a little phenidone. One of the possibilities for this odd color is colloidal silver.

 

[Pixophrenic]

Developers containing Hydroquinone may end up having a Hydroquinone Monosulfonate salt after use. This is produced by the reaction of quinone (a Hydroquinone oxidation product) with sulfite and is a developing agent, much less active than Hydroquinone. The release of halides (bromide, iodide) during development can also alter developer characteristics if the original formula doesn't have any in it, like D76.

Some relatively modern developers, such as Rollei Supergrain made by SPUR, contain both hydroquinone and hydroquinone monosulfonate. Would you say this is done to simulate ripening?

 

[Anon Ymous]

Some relatively modern developers, such as Rollei Supergrain made by SPUR, contain both hydroquinone and hydroquinone monosulfonate. Would you say this is done to simulate ripening?

I honestly have no idea why they do so. Didn't even know a developer that used Hydroquinone Monosulfonate except from E6 FD. To be honest, I don't see much to be gained by trying to simulate ripening. There are many nice developers out there that give fine results as is. Many replenishable developers too and this ripening can be achieved fairly easily.

In my book, Jacobsons "Developing" 18th edition, p. 206 there are both D-76 and replenisher formulas, with the replenisher having 10X the amount of borax as the developer. Is this a typo?
.

No, it's not a typo. Adox MQ Borax replenisher uses a large amount of borax too, but don't remember the exact figure.

 

[Lachlan Young]

I think redeposition of silver definitely occurs in solvent developers, but I am not sure if it does in a general case. Today at trying a new "acutance" recipe I saw for the first time the developer turning vivid green after use. This was essentially Rudolf Jarai formula I put in the resource, but metol substituted for by glycin and a little phenidone. One of the possibilities for this odd color is colloidal silver.

What film were you using for this test?

 

[Alan Johnson]

Some relatively modern developers, such as Rollei Supergrain made by SPUR, contain both hydroquinone and hydroquinone monosulfonate. Would you say this is done to simulate ripening?

I don't know the function of HQMS .It might ,being a final oxidation product, just slow the conversion rate of AgBr to Ag.Others may know more .IIRC PE has mentioned that Kodak wore working on a sucessor to Xtol containing thiocyanate..This might be unlocking some secrets of developers post Xtol.

 

[John51]

Labs used D76 in a replenishment regime - for each 8x10 (or equivalent) a certain amount of old developer was removed, and a certain amount of new developer replenisher was added. The developer replenisher was similar to the basic D-76, but not identical.
D-76 replenisher is no longer made by Kodak, but modern developers like X-Tol and T-Max RS are designed for self-replenishing - the developer itself serves as its own replenisher.

I get the replinishment idea but the original D76 is still collecting oxygen. After x number of prints, the soup is 80% D76 and 20% replenisher but the D76 that has been getting oxydised still works. At some point the original D76 will be down to 20% or less but the results will be as consistent as when it was 80% D76 or labs would have used something else.

For the replenisher to 'correct' the oxydisation of the original D76, it sounds like there has to be a regular workflow. Or maybe a minimum workflow? What happens when the lab is closed for a holiday period, can the soup sit there doing nothing but getting oxydised and be fine when the lab starts up again?

 

[Murray Kelly]

I have not had to do it but I understand a floating lid was used to reduce the surface area exposed to the air.

 

[MattKing]

I get the replinishment idea but the original D76 is still collecting oxygen. After x number of prints, the soup is 80% D76 and 20% replenisher but the D76 that has been getting oxydised still works. At some point the original D76 will be down to 20% or less but the results will be as consistent as when it was 80% D76 or labs would have used something else.

For the replenisher to 'correct' the oxydisation of the original D76, it sounds like there has to be a regular workflow. Or maybe a minimum workflow? What happens when the lab is closed for a holiday period, can the soup sit there doing nothing but getting oxydised and be fine when the lab starts up again?

The problem with your analysis is that you are differentiating too much between the "original" D76 and D76 plus replenisher.
In a properly running system, the working D76 solution reaches an equilibrium quickly, and the effect of both developing film and adding replenisher maintains that equilibrium. If properly maintained, a tank of fresh D76 that has been seasoned (by either adding starter or running a few rolls of film through it) should be in essentially the same condition and have the same constituent ingredients as a tank that has had hundreds of rolls run through it and been kept in equilibrium through replenishment.
And while oxydisation is one issue that needs to be dealt with through prevention and replenishment, it certainly isn't the only or even main one. In the past if a lab hadn't been using the D76 for a period, any necessary adjustments would be dealt with through the normal workflow of running a control strip through the D76 and then adjusting the "soup" in response to the control strip numbers.
Small volume users can accomplish something similar through short test rolls.

 

[Pixophrenic]

The problem with your analysis is that you are differentiating too much between the "original" D76 and D76 plus replenisher.
In a properly running system, the working D76 solution reaches an equilibrium quickly, and the effect of both developing film and adding replenisher maintains that equilibrium. If properly maintained, a tank of fresh D76 that has been seasoned (by either adding starter or running a few rolls of film through it) should be in essentially the same condition and have the same constituent ingredients as a tank that has had hundreds of rolls run through it and been kept in equilibrium through replenishment.
And while oxydisation is one issue that needs to be dealt with through prevention and replenishment, it certainly isn't the only or even main one. In the past if a lab hadn't been using the D76 for a period, any necessary adjustments would be dealt with through the normal workflow of running a control strip through the D76 and then adjusting the "soup" in response to the control strip numbers.
Small volume users can accomplish something similar through short test rolls.

This confirms my suspicion that offering D-76 for small tanks and recommending a fixed increment to extend the development time for each new film processed in a small tank is not quite correct. The correct use on a small scale would have been to develop a dummy fogged film, replenish and enter into a stable cycle, developing several films one after another and replenishing after each one. Should there be a time gap, a control strip is essential. This is hardly reliable if you do it with one liter to start with.