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Chris Patton's E-72 - Ascorbate-based variation of D-72

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grain elevator

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grain elevator submitted a new resource:

Chris Patton's E-72 - Ascorbate-based variation of D-72 - Ascorbate-based variation of D-72


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albada

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My record is based in the same link (alphalink) and The Darkroom Cookbook (2nd ed), and it has a couple of differences from yours. Here are the formula and related notes I recorded:

Dekol-type developer substituting ascorbic acid for hydroquinone and Phenidone for metol.​
​
Water (125°F/52°C) ......... 750 ml​
Phenidone ........................ 0.3 g​
Sodium sulfite (anhy) ....... 45 g​
Ascorbic Acid ................... 19 g​
Sodium carbonate (mono) ..... 90 g (77 g Sodium carbonate anhy)​
Potassium bromide .......... 1.9 g​
Water to make ................. 1000 ml​
​
USING THE DEVELOPER: Dilute between 1:1 and 1:4, with 1:3 for normal contrast.​
For 1+3, 2 minutes works well.​
NOTE: 3.0 g of metol may be substituted for the Phenidone.​
Formula #81, The Darkroom Cookbook, 2nd Edition, Stephen G. Anchell, p.192​

I just now checked The Darkroom Cookbook, 3rd edition, formula #84 on page 251, and it agrees with the above formula. Your formula is missing restrainer (Potassium bromide) which is present in nearly all paper developers, and its sulfite of only 24g is wrong. Most paper developers have around 12g/L of sulfite in their working solutions, which is around 48 g/L in a concentrate to be used 1+3.

Mark
 
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Philippe-Georges

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The original document as published by Cris Patton at stanford.edu which I am using it since AGFA's demise, in 2006, to replace their Neutol Plus. ADOX's Neutol Eco didn't exist at the time, but I still go on brewing it (in demineralised water), as I like doing it.
It is a very good paper developer, Dektol type (which Neutol was too), and I dilute the 1l stock, made as described in this attachment, with 1,5l demineralised water and process for 3 min at 22°C, as I like intensive black tones in my prints.
The work solution holds rather long if you systematically replenish with 10% fresh work solution immediately after each printing session.
 

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  • “CPI - E72”.pdf
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grain elevator

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Thank you two for the contributions! I've corrected the amount of sulphite, no idea what caused me to copy it wrong from my notes. The KBr is there.
Philippe-Georges, the recipe you post interestingly doesn't have the KBr and a little more phenidone. I haven't tried that one, have you compared the two? I suppose with KBr it's a bit more contrasty?
 

Philippe-Georges

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According to the formula as originally (I think so) published by Chris Patton, there is KBr in his E-72, but there is none in his E-76, see second attachment:
But In the version, which is supposed to be by his hand too and as I attached in my previous post, there is none, which puzzles me.
Anyway, I follow the formulas, as you can see in the first attachment below, and add KBr in the E-72 (10 drops of a saturated solution of KBr in demineralised water per 1l stock)...
There is a third version published by him, where he writes about some modifications he did on Patrick Gainer's formulas:
 

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  • CHRIS PATTON.pdf
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  • “CPI - E76”.pdf
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  • “Modified from Patrick Gainer's formulas”.pdf
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mrosenlof

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I've used E-72 as my only (almost only) paper developer for several years now, might be ten years. My notes have the recipe with the KBr. It's easy to mix up at the beginning of the session, I have PC-glycol concentrate made up, so use that along with the appropriate amounts of Sulfite and Carbonate (and a dash more ascorbic acid). I mix directly to the 1+3 working strength. Tray life is at least a week. Most recently I developed about 60 8x10 equivalents in a week.

E-76 has been my main film developer for a couple of years now. I keep the sulfite/borax solution on hand, and I mix directly to working strength from the aklalai solution, phenidone in a 2g/100ml denatured alcohol solution and the vitamin C from a measuring spoon. I also add some benzotriazole (also in denatured alcohol) about .04g per working liter.
 

albada

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mrosenlof said:
Tray life is at least a week.
Click to expand...

Is the tray open to the air for a week? Or is it covered?
I find I get 2-3 sessions from Liquidol and ID-62, but if I store the developer in a bottle between sessions, it can last months. That's why I don't know what tray life means to people.
 

mrosenlof

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I put a flat lid on the tray when I'm done for the day. It's just a sheet of polycarbonate that covers the tray, no seal.
 

Loose Gravel

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Here's a favorite of mine. I've been using this a long time to avoid carcinogens. I mix as a concentrate. It does yellow, but that does not affect performance. This is copied from a posting here July 10th, 2011, by Gerald Koch.

Formula by Ryuji Suzuki
DS-14 Paper Developer

Sodium sulfite, anhydrous 12.0 g
Ascorbic acid 6.0 g
Dimezone S 0.2 g
Potassium bromide 1.0 g
Triethanolamine 5.0 ml
Salicylic acid 0.5 g
Sodium carbonate, monohydrate 30.0 g
Water to make 1 l

pH 10.4 +/- 0.2
 
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grain elevator

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Please consider adding it to the photrio resources! This thread is just the one that's automatically started when a resource is added. I added E-72 because I noticed the website with the recipe, which I had bookmarked, has disappeared. Adding to the resources here will help keep information like that accessible.
 
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Loose Gravel

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Alan, thanks for this. I never have much luck with Wayback machine. I haven't learned it yet I guess. I remember these pages before they disappeared. Patton's E-72 is easier to mix than what I've been using. Easier is good.
 
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grain elevator

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Loose Gravel said:
Alan, thanks for this. I never have much luck with Wayback machine. I haven't learned it yet I guess. I remember these pages before they disappeared. Patton's E-72 is easier to mix than what I've been using. Easier is good.
Click to expand...
 
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