E-72 Concentrate Update

This is an update of a trial I began in January, when I mixed up some E-72 (Phenidone, Ascorbic Acid version of D-72) in concentrated form (tripled all ingredients but minus the alkali). See my article in the Chem Recipes section for the details and formula.

I did a printing session two weeks ago, mixing up a liter of working strength from the concentrate in a 1:9 dilution (the concentrate was now more than three months old in a partially full bottle), and it has not discolored nor lost potency. After running 10 8X10's and 6 11X14's through the soup, I then saved the working solution for ten days until my next printing session. This time, without replenishment, I ran 4 8X10's and 12 11X14's through the soup, again with no loss of potency. The only thing was that for the last three prints of the session, I lengthened my development time to 1:45 from the usual 1:15 to get full development. So at the end of the session I dumped the remainder.

I'm still very pleased with the results, particularly the richness of the blacks and the long tonal scale. I'm satisfied that the concentrate (minus the alkali) will keep for a very long time, and the ease of mixing it 1:9 with water and throwing two tablespoons of sodium carbonate into the tray of diluted developer is about as cheap and easy as it gets.

Larry

Any update on your E-72, Larry?
Those are RC print numbers that you quote above? Would the developer do fewer FB?

Thanks for posting your results. After I run out of my Dektol stock, I'm looking to try E-72 as a general print developer. But I have an interest in using it as a high contrast developer in two bath development after a low contrast developer such as Ansco 120 or Ansco 130 (Adam's version without hyroquinine). Do you (or any of the other chemistry experts) see any problems with using a dilute 120 or 130 for 2 to 2:30min, then a tray with strong E-72 for 0:30 to 1min?

Thanks,
James

blackmelas said:

Any update on your E-72, Larry?
Those are RC print numbers that you quote above? Would the developer do fewer FB?

Thanks for posting your results. After I run out of my Dektol stock, I'm looking to try E-72 as a general print developer. But I have an interest in using it as a high contrast developer in two bath development after a low contrast developer such as Ansco 120 or Ansco 130 (Adam's version without hyroquinine). Do you (or any of the other chemistry experts) see any problems with using a dilute 120 or 130 for 2 to 2:30min, then a tray with strong E-72 for 0:30 to 1min?

Thanks,
James

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James,

The E-72 concentrate is still fine, now five months after mixing it up. I just did a printing session the other day with it, and the results look good. The numbers I quoted are for double-weight fiber-based paper, not RC, which I rarely use.

There's a much easier way than the one you suggest for using a low contrast and then a high contrast developer. Since Ansco formulas are metol-based and E-72 is Phenidone-based, I'm not sure you'll not end up getting some precipitating sludge in your E-72 from the incompatibility of Metol with Phenidone.

What you really should try is a two-bath formula with two different Bath A's (one low and one high contrast) and the same Bath B which contains only the alkaline activator.

Mix up your Ansco 120 for your soft Bath A (I label this SA, meaning Soft A), leaving out the alkaline activator.

Then mix up some Ansco 125 (same as Dektol) or Ansco 130 or E-72, again without alkaline activator) and label this HA (Hard A).

These solutions can be used again and again for many months. Since there's no activator, they simply get used up volumetrically, but not exhausted.

Mix up the Bath B (alkaline activator--Sodium Carbonate) each time right in the tray. I throw in a liter or water and 1/3 cup Arm&Hammer washing soda and it dissolves in minutes in the tray.

If your neg demands a softer contrast, run it through Bath SA and then directly with no rinse into Bath B.

If it demands a normal contrast, skip SA and do HA plus B.

By separating developing agents from activator, several things happen:

No temp/time controls are necessary. Any temp between 50 and 100F will do nicely. Cooler may take longer, and warmer shorter, but really it's irrelevant.

About 15-20 seconds is all you'll need in Bath A. Bath B, just leave it in long enough for development to come to completion. Could be anywhere from 30 seconds in fresh bath to a minute as the bath ages. Bath B does become exhausted eventually, but I've run 40 prints through a liter before it begins to wear out.

I printed this way for years with graded papers. The two Bath A's give the ability to get intermediate grades. A #2 paper in SA will give a 1 1/2 grade. A #3 in SA will give a 2 1/2, etc. The HA bath gives normal contrast for the paper grade.

With the new variable contrast papers, which I now use exclusively, the divided developer method is no longer the advantage it once was. I use a split filter method of printing to give me everything that's on the negative in the way of shadow and highlight detail, and then run it through a single developer. Normally, I'm using the E-72 concentrate as described in my article in the Paper Developers section of the Articles. But if I've got some high contrast negs, I can always mix up some Ansco 120 and get the results I want.

Good luck.
Larry

Thanks for the info and the ideas. I wasn't aware of a phenidone/metol incompatability but it makes sense. Some great ideas here that I'll try.
Best regards,
James

I'm envious of your results. Whenever I mix ascorbic acid in water, the activity dies off after a few days, whether the solution is acidic or not. Sulfite doesn't seem to help either.

Maine-iac said:

... the incompatibility of Metol with Phenidone. Larry

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Any incompatibility may have to do with the ratios and
or ph. Crawley's FX-7 has 1.5 grams metol plus .25 grams
phenidone. His FX-4 has the two plus hydroquinone.
Perfection XR-1 is a combination of the three.

Likely there are others of the two or three agent
developers. I've tested a carbonated phenidone print
developer; extremely low contrast with no blacks. Add a
little M and/or Q and what a change. Add A. Acid? Dan

psvensson said:

I'm envious of your results. Whenever I mix ascorbic acid in water, the activity dies off after a few days, whether the solution is acidic or not. Sulfite doesn't seem to help either.

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Perhaps one of Ryuji Suzuki's recipes with salicylic acid would change your luck.

psvensson said:

I'm envious of your results. Whenever I mix ascorbic acid in water, the activity dies off after a few days, whether the solution is acidic or not. Sulfite doesn't seem to help either.

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Peter, I don't think my results are anything special. The diluted working solution will only keep a few days--I've kept it as long as four days without any visible loss in activity. Haven't tried it longer than that.

But the concentrate (minus the carbonate) is now five months old and still potent. I don't know what's happening chemically to the Ascorbic Acid in the concentrate, but whatever it is, doesn't seem to affect the results. I'm diluting the concentrate 1:9. Usually, I just mix up a tray for one session and then discard it.

Larry

dancqu said:

Any incompatibility may have to do with the ratios and
or ph. Crawley's FX-7 has 1.5 grams metol plus .25 grams
phenidone. His FX-4 has the two plus hydroquinone.
Perfection XR-1 is a combination of the three.

Likely there are others of the two or three agent
developers. I've tested a carbonated phenidone print
developer; extremely low contrast with no blacks. Add a
little M and/or Q and what a change. Add A. Acid? Dan

Click to expand...

This is interesting, Dan. I'm not a chemist (except of the "bathtub" or "darkroom" seat-of-the-pants variety), and I'm glad to know that Metol and Phenidone are not incompatible in the right combinations. I just remember reading in some photo magazine article many years ago that mixing the two would form sludge. Just goes to show you can't believe everything you read.

I haven't tried adding Metol to a P/AA developer, but I have tried adding Q and you're right about the dramatic increase in D-Max and contrast.

Larry

E-72 uses Phenidone which tends to produce cold tones while D-72 uses Metol which produces slightly warm blacks. Therefore, E-72 is not going to produce the same results as D-72 or Dektol, the tonality will be different. This is why I have a problem with the name E-72 which implies that it is a perfect clone of D-72 which it is not.

Sulfites will not protect ascorbate ions from oxidation. In addition, without something to complex certain metal ions such as iron (III), E-72 is subject to the sudden death syndrome effecting all ascorbate developers. E-72 is a poor formula and Ryuji's two print developers are a much better choices.

[QUOTES=Gerald Koch]
"Sulfites will not protect ascorbate ions from oxidation."

Certainly not in any working strength developer. I did read
in an article concerned with pharmaceutical preservation
that at a ph of 5 and below, sulfite will preferentially
absorb oxygen. That information is likely of no
practical value to us in the darkroom.

"... without something to complex certain metal ions such
as iron (III)"

Do with or without complexing agents as one choses
in so far as preservation and cleanliness of solutions is
concerned. Some may wish to consider distilled water as
an alternative. Dan

Even distilled water of the kind we could or would want to afford may have enough iron atoms to trigger the process of ascorbate oxidation. It acts as a catalyst, according to Suzuki's findings, not as a reagent. A catalyst causes an increase in rate of a reaction without becoming part of the product. When this is the case, anything that enters the developer solution including even the ascorbic or isoascorbic acid itself may carry enough of the iron of the proper valence to be carried in with it. It is then necessary to poison the iron catalyst without poisoning anything else including the synergism between ascorbate and the other agent(s).
For most of my uses, a concentrate in an organic solvent seems to prevent the problem. The dilution by water begins the decay process, but that is not a problem for one-shot developmentof either film or paper. Very long tray life of the diluted glycol concentrates is not to be expected, in other words, although addition of some salicylic acid or a salicylate might help. I have not tried methyl salicylate, which ought to be soluble in glycol, and at least should make the developer smell good.

Gerald Koch said:

This is why I have a problem with the name E-72 which implies that it is a perfect clone of D-72 which it is not.

Sulfites will not protect ascorbate ions from oxidation. In addition, without something to complex certain metal ions such as iron (III), E-72 is subject to the sudden death syndrome effecting all ascorbate developers. E-72 is a poor formula and Ryuji's two print developers are a much better choices.

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I didn't invent the name of the formula; to my knowledge, it's usually attributed to Chris Patton, and I didn't adopt it because it was supposed to be a substitute for Dektol. I adopted it precisely because I wanted a Phenidone/Ascorbic Acid formula. So, I don't care what it's called.

I agree that mixed as is, it is subject to the sudden death syndrome. My experiments with a concentrated version minus the carbonate were to address that very issue. I just made some lovely prints yesterday with five month-old concentrate kept in a partially-filled plastic bottle. It worked just fine--no diminution of either potency or quality. I cannot tell the difference visually between prints I made using Ryuji's fine (but more complicated) DS-14 formula and my E-72 concentrate. The tonal color appears to be the same, as do the keeping qualities. Being the lazy soul I am, I go for the simpler and easier.

Larry

Maine-iac said:

I just made some lovely prints yesterday with five month-old concentrate kept in a partially-filled plastic bottle. It worked just fine--no diminution of either potency or quality. I cannot tell the difference visually between prints I made using Ryuji's fine (but more complicated) DS-14 formula and my E-72 concentrate. The tonal color appears to be the same, as do the keeping qualities. Being the lazy soul I am, I go for the simpler and easier.

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The reasons you state have convinced me to try your E-72 concentrate (and/or the metol based version in the Darkroom Cookbook). If it makes nice prints and there are fewer, simpler chemicals in it, then I'm all for it. Once again thanks, Larry, for taking the time to post your results.
James

Maine-iac said:

I cannot tell the difference visually between prints I made using Ryuji's fine (but more complicated) DS-14 formula and my E-72 concentrate. The tonal color appears to be the same, as do the keeping qualities. Being the lazy soul I am, I go for the simpler and easier.

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I've also run this test (using E-72 made with metol rather than phenidone, though), and the two prints look indistinguishable, save for unique non-developer markings (dust specks here vs. there, etc.).

My conclusion regarding laziness is different, though. DS-14 can be used with replenishment; make it up without the potassium bromide and it's a replenisher (I label mine "DS-14-R," although I've never seen Ryuji Suzuki call it that). I process in trays, and when I'm done, I pour the developer back into its 1-liter bottle. I then top it up using DS-14-R. It's possible to go through at least one liter of DS-14-R over a 3-month period in this way without affecting print quality; I'm now starting on my second liter of DS-14-R. The DS-14 working solution darkens (I suspect from stuff coming off of the prints), but continues to work. The end result is that, although the DS-14 and DS-14-R are more complex to make than E-72, you need to make them less often, so in the long run there's less work to making the DS-14/DS-14-R.

Of course, now that the Silvergrain Tektol line is out, being improved DS-14 developers, if you prefer spending money to expending effort, you can just buy Tektol Standard. I bought some to try it out; it arrived yesterday, but I probably won't get around to trying it for a while -- perhaps not until I finish off my current batch of DS-14-R, which is likely to be another 2-3 months.

gainer said:

Even distilled water of the kind we could or would want to afford may have enough iron atoms to trigger the process of ascorbate oxidation.

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I was hoping this topic might inspire a glycol-based variation of Maine-iac's idea and experience on this..... I just had a sudden-death occur for the first time with DS-14. This has been my "go to" paper developer for the past year or so and I mix it at 4X concentration for 1+3 use (this seems to be the highest concentrate level that still is quite readily soluble). This incident made me wish for a solvent based paper developer that gave similar results. The DS-14 gives me just a touch of warmth on Ilford MG materials that is about right for most of what I've been doing. I'm going to be using up some other things here for some large quantity printing on a project that isn't hyper-critical regarding nuances of paper developer but I'm going to try some of the Maine-iac version of the E-72 next. My recent DS-14 experience could be a fluke or an error on my part as it has proven very stable and long-lived prior to this.

Such a venture is quite easily undertaken. If you were to put those ingredients of
DS-14 that can be dissolved in TEA or glycol into a concentrated organic solution and the other ingredients, which are not nearly so sensitive to water contaminants into a water solution, or even mix them as needed from the solids, you could have a working solution that would last the immediate session with no problem.

You can certainly dissolve the reducing agents in glycol. Metol is not very soluble in glycol, but its base is, and the base is easily prepared with a little TEA and a tiny bit of water. Phenidone and the p-aminophenol base which is commercially available, are quite soluble in glycol, as is hydroquinone. What is left of DS-14, even including the salicylic acid, is soluble in water. You wind up with an A-B developer with long storage capacity for the concentrates and long tray lofe for the working solution.

gainer said:

Such a venture is quite easily undertaken. If you were to put those ingredients of
DS-14 that can be dissolved in TEA or glycol into a concentrated organic solution and the other ingredients, which are not nearly so sensitive to water contaminants into a water solution, or even mix them as needed from the solids, you could have a working solution that would last the immediate session with no problem.

You can certainly dissolve the reducing agents in glycol. Metol is not very soluble in glycol, but its base is, and the base is easily prepared with a little TEA and a tiny bit of water. Phenidone and the p-aminophenol base which is commercially available, are quite soluble in glycol, as is hydroquinone. What is left of DS-14, even including the salicylic acid, is soluble in water. You wind up with an A-B developer with long storage capacity for the concentrates and long tray lofe for the working solution.

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Yes, and it works, see:

(there was a url link here which no longer exists)

At any rate, my DS-15/TEA stock concentrate was still working ok on 3/02/2006. I mixed it on 7/16/2004.

I'll test my DS-14/TEA stock concentrate and see if it's still alive as well.

By the way, I was able to dissolve sufficient Metol in hot TEA to make the concentrate. If I do it again, I'll use Pat Gainer's process of reacting the Metol and Ascorbic Acid with a small amount of TEA and water, then add warm Propylene Glycol.

I tested the activity of my my DS-14/TEA stock concentrate (mixed 3/16/2004). I mixed a few ml of the stock concentrate in 250ml of water and stirred in a spoonful of Sodium Carbonate. This solution quickly turned an exposed 2 inch piece of 35mm Efke 25 film a solid and uniform black.

My Macbeth color densitometer tells me that I am getting significantly higher density on this piece of film with the Blue channel than I am with the Visual channel. This indicates stain formation (Metol is a staining developer in the absence of sulfite).

Think I'll try it again with a spoonful of Sodium Sulfite added to the mix.

craigclu said:

I just had a sudden-death occur for the first time with DS-14.

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I would very much appreciate if you could elaborate the condition in which this occured. I've done some tests in the past, but I've never seen a sudden death, even in an open tray. I would imagine significant chemical contamination or strong UV irradiation was made to the solution. If you added phosphate, for example, it could kill the developer fast.

This has been my "go to" paper developer for the past year or so and I mix it at 4X concentration for 1+3 use (this seems to be the highest concentrate level that still is quite readily soluble).

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DS-14 can be made 5x stock (to use 1+4) by reducing the water. Tektol Standard is 10x concentrated (to use 1+9) and it increases the convenience very much.

Ryuji said:

I would very much appreciate if you could elaborate the condition in which this occurred. I've done some tests in the past, but I've never seen a sudden death, even in an open tray.

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I had mixed this a few weeks before using it and had opened the jug to do some printing. I am as likely (probably more) to have made an error in the original mixing as to have had the developer fail... After I hit the post button on the comment that I made, I thought about the term "sudden failure" and realized it wasn't a good description of the event. I've always been happy with the stability of it and have been quite surprised at the continued activity after uncovering my trays a day or two later and continuing to print with it. It's actually the most stable, long-lived paper developer that I recall ever using.

My habit of 3+1 comes simply from it being quite easy to get into solution at that concentration and filling my storage bottle with water 3 times and emptying into the tray gives me the right final volume that I like to start printing with. I'll be giving the commercial version a try soon, too.

Maine-iac said:

This is an update of a trial I began in January, when I mixed up some E-72 (Phenidone, Ascorbic Acid version of D-72) in concentrated form (tripled all ingredients but minus the alkali). See my article in the Chem Recipes section for the details and formula.

I did a printing session two weeks ago, mixing up a liter of working strength from the concentrate in a 1:9 dilution (the concentrate was now more than three months old in a partially full bottle), and it has not discolored nor lost potency. After running 10 8X10's and 6 11X14's through the soup, I then saved the working solution for ten days until my next printing session. This time, without replenishment, I ran 4 8X10's and 12 11X14's through the soup, again with no loss of potency. The only thing was that for the last three prints of the session, I lengthened my development time to 1:45 from the usual 1:15 to get full development. So at the end of the session I dumped the remainder.

I'm still very pleased with the results, particularly the richness of the blacks and the long tonal scale. I'm satisfied that the concentrate (minus the alkali) will keep for a very long time, and the ease of mixing it 1:9 with water and throwing two tablespoons of sodium carbonate into the tray of diluted developer is about as cheap and easy as it gets.

Larry

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Hi @Maineiac,

"See my article in the Chem Recipes section for the details and formula."
Could you provide a link to it please?

measwel said:

Could you provide a link to it please?

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@Maine-iac hasn't been around since 2016, so hey may not respond anymore. There is a formula for E-72 here though: https://www.photrio.com/forum/resources/chris-pattons-e-72-ascorbate-based-variation-of-d-72.460/
Apparently, @Maine-iac made a concentrate thus:

tripled all ingredients but minus the alkali

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I interpret this as:

Phenidone: 0.9 g
Sodium Sulphite: 135 g
Ascorbic Acid (Vit. C): 57 g
KBr 5.7 g

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When mixing this into a working strength solution, you would take 1 part of the concentrate and add 2 parts of water, and also add 90g/liter sodium carbonate. From here, you would dilute further at 1+1 to 1+4 depending on how you want to use it. You could also go from the concentrate right to the 1+1 plus 1+4 working strength, of course. It's undefined in the recipe I linked to what form of sodium carbonate is used, but when undefined, it's usually monohydrate.

Hope this helps!