DIVIDING ERIC PATTON'S E-76 FORMULA

[leicam5]

Curious by what I read on the net about divided D-76, I wanted to do the same with Eric Patton's Metol/Hydroqiunone free E-76 formula.
So this is what I did :
I inspired me on the David Vestal's Divided D-76 formula I found on greenspun.com and divided the E-76 about the same way:

Part A -> 1 lit
Phenidone: 20 cc 1% solution
Sodium sulfite: 50 gr.
Ascorbic Acid: 8 gr.

Part B -> 1 lit
Sodium sulfite: 50 gr.
Borax: 12 gr.

Film: Tri-X 400/120 @ 400 ASA
Processing : all @ 20°C; pre wet +/-5 min, Part A 4 min, Part B 10 min (no intermitted rinsing) then stop, fix and wash the normal way.
The results where catastrophic there was a very faint image, only the highlights came slightly trough, useless to print.
So, can somebody tell me what I did wrong?
Thanx!

[Alan Johnson]

Here is the sorry story of my failure:
http://www.apug.org/forums/forum37/3...developer.html
Basically, you can get an image using a high enough concentration of phenidone and a sufficiently alkaline B-bath but it is not 2-bath development as generally meant.The image is produced by carry-over of phenidone on the film ,tank and reel making the B-bath a developer on its own, there is no exhaustion of the phenidone as would be the case if it was only there absorbed on the emulsion.
I never read of a way round this problem, it does not occur ,eg, with Thornton's 2-bath.

[leicam5]

Thanx Alan, but this Thornton formula has Metol/Hydroquinone in it, that was my reason for going around D-76...

[Jordan]

I also once attempted to make a divided ascorbate-phenidone developer, with no success. I think there is something particular about metol (or possibly hydroquinone) that lends itself particularly well to use in a divided developer.

[Zathras]

The problem was most likely caused by the first bath being way too acidic for development to take place. Ascorbic acid is a very good reducing agent, but it needs an alkaline environment AND another reducing agent like phenidone or metol to successfully develop film.

As an experiment, why not try converting the ascorbic acid to sodium ascorbate by combining it with sodium bicarbonate in water prior to adding it to Solution A. Try Googling "Patrick Gainer" + "sodium ascorbate" to find out how much sodium bicarbonate to add to the ascorbic acid to neutralize the acidity.

If you decide to try this, post back and let us know how it worked.

Mike

[Zathras]

I also once attempted to make a divided ascorbate-phenidone developer, with no success. I think there is something particular about metol (or possibly hydroquinone) that lends itself particularly well to use in a divided developer.

Did you use ascobic acid or sodium ascorbate?

Mike

[Gerald C Koch]

I also once attempted to make a divided ascorbate-phenidone developer, with no success. I think there is something particular about metol (or possibly hydroquinone) that lends itself particularly well to use in a divided developer.

It is not necessary to use metol in a two bath developer. Phenidone is used in several formulas. Paul Farber published two in the magazine Travel and Camera (now defunct).

Ryuji Suzuki makes the point on his website that the simularity between hydroquinone and ascorbic acid is only superficial. On this basis one would not expect to be able do a simple substitution.

Designing a developer is not a simple task and it requires knowledge in several fields. There were a couple of articles in Photo Techniques by the two inventors of Xtol detailing their work. It took them a full year before they came up with a preliminary formula that could be presented to Kodak.

[Ian Grant]

There's not supposed to be any development taking place in the first bath.

The issue is that there's not any significant additivity taking place when the film's placed in the second bath and Phenidone works weakly on it's own unlike Metol.

Ian

The problem was most likely caused by the first bath being way too acidic for development to take place. Ascorbic acid is a very good reducing agent, but it needs an alkaline environment AND another reducing agent like phenidone or metol to successfully develop film.

As an experiment, why not try converting the ascorbic acid to sodium ascorbate by combining it with sodium bicarbonate in water prior to adding it to Solution A. Try Googling "Patrick Gainer" + "sodium ascorbate" to find out how much sodium bicarbonate to add to the ascorbic acid to neutralize the acidity.

If you decide to try this, post back and let us know bhow it worked.

Mike

[nworth]

A couple of years ago I had trouble with Tri-X in divided developers, so I stopped trying with it. I could be something about the film, or it could be something else. In any case, you need a point of comparison when compounding a new developer. Develop test rolls in both your formula and in the Vestal formula and compare the results. If possible, also compare them with D-76 and E-76.

[eSPhotos]

Film: Tri-X 400/120 @ 400 ASA
Processing : all @ 20°C; pre wet +/-5 min, Part A 4 min, Part B 10 min (no intermitted rinsing) then stop, fix and wash the normal way.
The results where catastrophic there was a very faint image, only the highlights came slightly trough, useless to print.
So, can somebody tell me what I did wrong?
Thanx!

Isn't presoaking the culprit?
I remember reading somewhere not to presoak for 2 bath developers. This makes sense because water is already in the emulsion and no room for Part A.