Splitting developers into two baths.

The Film Dev Cookbook talks about D23 and D76 as two baths. I am wondering if such developers as FX2 or other A/B stock developers with the alkali in the second bath being used in the two bath style; A wider temperature range and X minutes in each. Are there limiting factors I'm not aware of? In the case of my interest FX2, A solution is Metol, Sodium Sulfite (only 35g) and Glycin. The B solution is Potassium Carbonate which falls mid-strength to other alkali's.

For my film, I use D76. Although I've dabbled in HC110. But when it comes to paper, I'll mix in 2 baths or together sometimes Dektol and Selectol. Can get GREAT results!

waynecrider said:

The Film Dev Cookbook talks about D23 and D76 as two baths. I am wondering if such developers as FX2 or other A/B stock developers with the alkali in the second bath being used in the two bath style; A wider temperature range and X minutes in each. Are there limiting factors I'm not aware of? In the case of my interest FX2, A solution is Metol, Sodium Sulfite (only 35g) and Glycin. The B solution is Potassium Carbonate which falls mid-strength to other alkali's.

Click to expand...

Recall that Geoffrey Crawley designed FX-2 to be used as a one shot developer.

A liter of FX-2 working developer contains:

Per liter of water:

3.5 grams of anhydrous Sodium Sulfite
0.25 grams Metol
0.75 grams Glycin
7.5 grams Potassium Carbonate (crystals)
Potassium Iodide 0.001% solution, 5ml
Pinacryptol Yellow 1:2000, 3.5 ml

Reference: The British Journal of Photography Annual 1970, page 213

Crawley made this stuff to be special, and it is. Look at what it is, just Beutler's with a little glycin to lift the highlights. Two bath, might as well just use a Metol / Carbonate.

Typical Crawley, identify a specific purpose, nail the developer.

As for Beutlers, a good developer it there ever was one,
it is HIS take on the WW1 era AGFA Metol Formula 1,
diluted as AGFA directed for stand developer.

AGFA 1
Metol 15
Sulfite 75
P Carb 75
Bromide 2

Dilute to suit.

AGFA 3
Metol 1
Sulfite 5
P Carb 5
10% Bromide, as needed

In both cases, S Carb works fine.

You might enjoy the results that a Split #1 would give. Divide the Sulfite evenly for A & B. Reduce the metol to 5 or so. If you think the highlights are too soft, add some glycin to A.

I've used many split developers, with great results. I think you could split almost any developer.

In situations of EXTREME contrast, I have even split Windisch pyrocatechol. E6 first developer, also, with the film desensitized and developing by inspection.

If needed, you can cycle 1. A, B, rinse thoroughly 2. A, B, rinse thoroughly, etc.

Sulphite is needed in the A bath only, generally, since its function is to prevent the reducing agent from oxidizing. I do wonder, though, whether the carryover of reducing agent into B may produce biproducts which could influence the development. If so, sulphite in B could have a useful function.

bowzart said:

I've used many split developers, with great results. I think you could split almost any developer.

In situations of EXTREME contrast, I have even split Windisch pyrocatechol. E6 first developer, also, with the film desensitized and developing by inspection.

If needed, you can cycle 1. A, B, rinse thoroughly 2. A, B, rinse thoroughly, etc.

Sulphite is needed in the A bath only, generally, since its function is to prevent the reducing agent from oxidizing. I do wonder, though, whether the carryover of reducing agent into B may produce biproducts which could influence the development. If so, sulphite in B could have a useful function.

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Sulfite is alkaline and is a silver solvent. Sulfite is also used to prevent the formation of image stain.

Many of us have gone through a period of experimenting with split developers.

Have Fun!

If you are concerned about the effects of carryover from A to B, consider using B as one-shot.

bowzart said:

Sulphite is needed in the A bath only, generally, since its function is to prevent the reducing agent from oxidizing. I do wonder, though, whether the carryover of reducing agent into B may produce biproducts which could influence the development. If so, sulphite in B could have a useful function.

Click to expand...

No conjecture need apply. While a few drops of A winds up in B, it isn't enough to alter anything. If it was, Diafine and would not have the great bath life it does.

Although the MSDS for Bath B only lists sodium carbonate, a visual look at the powder shows a healthy dose of sodium sulfite, too. Because of the low toxicity, it does not need to be reported on the MSDS.

Tom Hoskinson said:

Recall that Geoffrey Crawley designed FX-2 to be
used as a one shot developer. A liter of FX-2 working
developer contains: Per liter of water:

3.5 grams of anhydrous Sodium Sulfite
0.25 grams Metol
0.75 grams Glycin
7.5 grams Potassium Carbonate (crystals)
Potassium Iodide 0.001% solution, 5ml
Pinacryptol Yellow 1:2000, 3.5 ml

Reference: The British Journal of Photography Annual
1970, page 213

Click to expand...

Using a 500ml portion for a 120 roll that would be
1/8 gram metol and 3/8 gram of glycin. Not much
there to carry forward to the B portion.

I'd think FX-2 a true compensating one-shot.
Isn't compensation the name of the game
when using A - B developers? Dan

working ratios are different for single shot vs split two bath development. mr king has split pyrocat hd into a two bath and the ratios are 1:10 for both baths. if you were to do that with fx-1, the A bath would not yeild enough metol as the gelatin absorbs it. mr thorton has done the hard work when it comes to working out the appropriate metol quantity and puts the level at 6.5 g/L. i've also split fx-4. it pushes well but it doesn't tolerate extreme temperature variations. here in Australia ( NSW ), in summer, my A bath with be at least 26degC. the highlights eventually exhaust, but the highlights are normally blown out by then, so i never leave it in bath B ( borax 12g/L ) for more than 2-3 min. hope this helps.