DIVIDING ERIC PATTON'S E-76 FORMULA

[Jordan]

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 Ian mentioned, divided developers are usually formulated such that minimal or zero development takes place in Bath A. The pH of these baths is usually neutral to slightly acidic. Having an alkaline Bath A in which extensive development takes place defeats the purpose of using a divided developer.

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.

I'm well aware of this Jerry. The issue the OP has is not one of substitution, but of trying to take a well-known single-bath developer and turn it into a two-bath developer. With a bit of fiddling this can be accomplished pretty easily for M or MQ developers like D76, D23, etc. Not so for ascorbate developers.

Two-bath developers rely on the ability of the emulsion to swell and absorb developing agent in a neutral to slightly acidic Bath A, which is then activated in the alkaline Bath B. If no developing agent is absorbed, the film will end up un- or under-developed, as the OP observed. Absorption into the emulsion depends on pH, ionic strength, and chemical structure. I know of no two-bath developer that does not contain either metol or hydroquinone (or maybe catechol or pyrogallol), which is why I suspect that these developing agents are somehow "privileged" in their ability to be absorbed into emulsions. They are all phenolic type developers (as opposed to phenidone and ascorbic acid) but beyond this, I don't know the nature of the structure-property relationship.

[Relayer]

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.

change Part B to next solution:
Sodium Sulfite 30g
TEA 30g
Water 1lt

why? because http://www.apug.org/forums/forum37/8...-acid-dea.html

other solution - replace Ascorbic Acid with Sodium Ascorbate. simple mix Part A as follow:

Part A -> 1 lit
Phenidone: 20 cc 1% solution
Sodium sulfite: 50 gr.
Ascorbic Acid: 8 gr.
Sodium carbonate: 2.4 gr
Sodium Metabisulfite: 5 gr

2.4g of Sodium Carbonate + 8g of Ascorbic Acid produre 9g of Sodium Ascorbate.
Sodium Metabisulfite required (see Diafine formula) because otherwise development started in bath A