What are we talking about here...? (aging of D-76)

Arvee

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I have read in numerous places by notable experts that the standard formulation for D-76 changes pH over time in storage and will ultimately increase developer activity. This worried me and I discontinued using D-76 because of this fact but I really like the results I get with the developer.

How serious is this problem? Are we talking a stop overdevelopment, a paper grade difference in contrast? What kind of inconsistency are we talking here? I would like to quantify the magnitude of the problem and possibly, if not too serious, go back to, in my way of thinking, a great developer.

Is there anything that can be done to mitigate the problem with the standard formula other than going to one of the 'mixed from scratch' variants?

Anybody?
 

Roger Hicks

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It's weirder than that. According to a very reliable source (Mike Gristwood, late of Ilford) it actually cycles up and down. Using D76d (the buffered version, which I believe is what is sold in the USA) will, I think, remove or greatly diminish this problem.

The degree of inconsistency is however trivial, far less than you will get by re-using a non-seasoned developer, where film speed and developer activity fall steadily as a result (mainly) of bromide build-up until the developer is fully seasoned, at which point you're running about a stop slow if you develop to ISO standard contrast.

Also, look at it this way. If you never had a problem when you were using it, why did you feel the need to stop?

Cheers,

R.
 

raucousimages

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Solution #1 Use your developer up fast. (Save up enough film to use a full bottle)

#2 Use Ilford ID-11. It is suposed to be the same as D-76d.
 

Tom Hoskinson

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The current (2006) Kodak and Ilford versions of D-76 (i.e. D-76 and ID-11) are both the equivalent of D-76d.

I am using Kodak D-76 (the most current Kodak packaged version) as a control developer for developer evaluation. I use it as a one-shot.

If you want to use D-76H (the Haist version of D-76) and don't want to mix it yourself, you can buy it from Photographer's Formulary
 

Photo Engineer

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A simple way to avoid this problem, which also takes place with Dektol btw, is to let it stand 3 days or about that, before using it.

The reason is simply, that hydroquinone reacts with oxygen and sulfite to form hydroquinone sulfonate which is less active, but it also forms sodium hydroxide which raises the pH. These two effects see saw back and forth as the activity of the developer gradually decreases with age.

It happens with any hydroquinone containing developer that is supplied in powder form. It is really no big problem after about 3 days. Then the developer, in my tests, stays constant for weeks until age finally begins to take over and it decays into developer death.

This is reported and described well by Haist and Mees and Mees and James in their texts. They give all of the chemical structures and go into far more detail than you would ever want to know.

BTW, HQ containing developers can be designed that don't do this, as noted above and elsewhere.

PE
 
OP
OP

Arvee

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Thanks, all, for the quick responses. I picked up a link on another site that answered a lot of questions for me. Hopefully it will be helpful to other readers.

http://www.udmercy.edu/crna/agm/phenvitc.htm

Thanks again, and if anyone has comments about the data on the link I would be interested in hearing that.

Thanks!
 

Roger Hicks

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Grant Haist is not convinced that ANY practical developer needs more than one developing agent. Despite his titanic status, there are others (well informed others) who disagree, especially for re-usable and seasoned developers.

For my money, anything without hydroquinone isn't a D76 variant at all, but a completely different kind of developer -- and Grant himself made the point (in conversation, the only time I was privileged to meet him) that the activity of hydroquinone is very temperature dependent. And although Geoffrey Crawley is almost certainly less of a theoretician than Grant (I know Geoffrey rather better), his developers are very highly regarded indeed and he often uses three developing agents.

My own belief is that developer design is more like alchemy, or possibly music, than science. You can predict with a fair degree of accuracy what won't work -- but the only way to see what will work well (if there are no strong theoretical objections to its working at all) is to try it and see.

Cheers,

R.
 

Photo Engineer

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Roger;

You have got that right! Just keep trying.

Grant and I often discussed this, and I differed with him about being able to use only one developing agent. I felt that two developers were often needed for B&W but not color, but Grant and I both agreed with Bill Troop that 3 developers are not needed for a good developer formulation.

If you need 3, something is wrong with the formula goes the old saying.

The only development that I have been able to carry out with success with only one developing agent was either thermal development or at very high pH values such as in instant imaging. Otherwise, I could generally find some fault with the developer solution.

The best type of developer solution was what we called an electron pump developer or an ETA (electron transfer agent) developer. This work is unpublished as far as I know. They are extremely active and very long lived.

PE
 

eddym

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Ron, what is the shelf life of D76 after it's been mixed? And I'm assuming it would oxidize faster in a non-full bottle, right? Any guidelines?
 

Roger Hicks

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Photo Engineer said:
I felt that two developers were often needed for B&W but not color, but Grant and I both agreed with Bill Troop that 3 developers are not needed for a good developer formulation.
Click to expand...

We all agree in theory about the pointlessness of 3 dev agents, but some of Geoffrey's devs are very highly regarded, so I'm happy to stretch the point and say, well, it probably doesn't add much to the price, and I can't be bothered to work out which one is useless.

I have to add that I have never verified which (if any) of Geoffrey's devs have 3 agents -- this is from a reliable third party -- nor have I discussed it with him. Next time I talk to him I shall endeavour to do so.

Cheers,

R.
 

Photo Engineer

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Eddy;

I'm sorry to say that I follow Kodak's guidelines for D76 keeping as my original film is too valuable to subject to possibly bad developer. I've never stressed it out.

Roger;

Developing agents rely on one of two methods for working together. One is called superadditivity where the mixture is much more active than either one alone. The other is electron transfer, in which there is no big increase in activity of one over the other but the combination is very effective and long lived as the developers seem to recycle each other.

To date, no evidence exists as to what goes on in 3 developer mixtures that cannot be achieved by rebalancing the other 2.

PE
 

Keith Tapscott.

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If you are using the commercially packaged Eastman Kodak D-76(TM), or Ilford`s own ID-11(TM), I wouldn`t worry about this at all. These developers have been tried and trusted over several decades and very well studied and both companies wouldn`t allow an inconsistent product to be sold. The commercial formula from both Kodak and Ilford have probably been modified over the original "published" formula.
 

Roger Hicks

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Photo Engineer said:
Eddy;

To date, no evidence exists as to what goes on in 3 developer mixtures that cannot be achieved by rebalancing the other 2.

PE
Click to expand...

Dear PE,

Absolutely. My sole point is that as they work, I'm disinclined go go behind the 'black magic' aspect. I'm sure that someone like yourself, or Grant, could find out (relatively) quickly and easily whether it was superadditivity or electron transfer, and suggest a rebalance -- though I have to admit that I had thought that the two mechanisms are both forms of either regeneration, or the formation of transient compounds.

All I'm saying is that I'll go for something that works for me, even if the 'theory' behind it is flawed or non-existent (cf variable contrast printing with two filters instead of one, without localized burning or dodging at the different grades).

Cheers,

R.
 

Photo Engineer

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I agree. Use what works.

Usually, if you have 2 developing agents that work weakly at say 1 g/l alone and then at 2 g/l just a bit more, then if you use 1 g /l of each and it works at say 10x the level of 2 g/l of either it is superadditivity.

If you have 2 developers that are strong or medium, and mix them as above and they gain a bit but last longer, then it is by means of an electron pump.

The latter are hard to design. Few compounds act this way.

Dektol is one of the former type. I've worked with quite a few of the latter type. Often the latter type combine aspects of both. The main characteristic of them is that they last and last and last because the developing agents can't be easily destroyed by air or use. The work is largely unpublished on this, but the method was used in Kodak instant film.

PE
 

Roger Hicks

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The first, I had understood. The second, I had not. (In fact I'm not sure I do now, but at least I think I do). Thanks VERY MUCH.

Cheers,

R.
 

Photo Engineer

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Ok, Roger, here is another item on this.

If you have a 'pump' mechanism, and vary one or the other, and one controlls the activity more than the other, it is the governing developer in the pair. If both do, there may be superadditivity.

In fact, you can have both superadditivity and ETA activity going on at the same time, and usually you do, but it has not been fully recognized as such by most workers.

PE
 

dancqu

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Roger Hicks said:
For my money, anything without
hydroquinone isn't a D76 variant at all.
Click to expand...

My thinking also. A real misnomer. IIRC Haist left
in his h formula that little borax. I think that little
borax was Kodak's first effort to steady D-76's
ph rise due to the reaction PE has mentioned.
The most recent version is more buffered.

Without the hydroquinone there is no point in
retaining that pinch of borax. So what's left?
Metol and sulfite, a weak D-23. Dan
 

Photo Engineer

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It is my understanding that ACC has closed down a lot of its analog photo labs in preference to digital. I wish professor Jones the best.

PE
 

Gerald Koch

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dancqu said:
Without the hydroquinone there is no point in
retaining that pinch of borax. So what's left?
Metol and sulfite, a weak D-23. Dan
Click to expand...
Not true, the borax is to counteract the acidity of the Metol. Without this small amount of alkali the developing times for D-76H and D-76 would be quite long. Everything must be the same except for the omission of hydroquinone in order for the two developers to have similar development times..
 

Photo Engineer

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HQ and Metol form a synergistic pair, with the resultant activity much higher than equal amounts of either would give.

PE
 

Gerald Koch

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If anyone is worried about inconsistency when using D-76 then they should switch to HC-110 as a one-shot. This developer was designed by Kodak to produce results almost identical to those of D-76 without the latter's problems. See the information about HC-110 on Kodak's website.
 
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