J.W.Shaw - Hydroquinone p-Aminophenol Developer

[Ian Grant]

Warm Toned Print developer. (Using Rodinal)

Solution A

Hydroquinone 16.7 g
Sodium Sulphite 91 g
Citric Acid 6.25 g
Potassium Bromide 3.12 g
Water to 1 litre

Solution B

Sodium Hydroxide 16.7 g
Water to 1 litre

Solution C Potassium Bromide Solution 10% (!00 g/litre)


To Use:
24 ml Soln A
24 ml Soln B
1 ml Rodinal (Agfa)
12 ml Soln C
100 ml Water

Originally formulated for lantern slides this developer works well with warm tone papers.

This is slightly different to the previously posted version.

[hasselbladuser]

Hi,

What's in the rodinal that makes it necessary to add to this developer mixture?

Jeroen

[Ian Grant]

Rodinal is a concentrated developer containing p-Aminophenol. It's normally used diluted between 1+25 to 1+100. So in this case it's used in combination with Hydroquinone.

Using 2 developing agents together give additivity, usually it's Metol or Phenidone & Hyroquinone/Glycin/Pyrocatechin, but p-Aminophenol can be used instead and in this developer gives very fine grain which in a print causes greater warmth.

Ian

[hasselbladuser]

Oke, that's interesting, thanks for clarifying!

Jeroen

[gainer]

I suppose one could use p-aminophenol directly, but the amount required to match the recipe would be so small as to be difficult to measure consistently. The amount of p-aminophenol in a liter of Rodinal stock is at most 100 grams, or at most 0.1 grams/ml. It's easier to measure a ml of liquid than 0.1 g of powder.

[Ian Grant]

Interestingly when this developer was formulated Rodinal & the Ilford equivalent Certinal were one of the recommended as Bromide paper developers, at 1+30 so it may have been very popular. After all most companies made a p-Aminophenoll equivalent, Kodak - Kodinol, May & Baker, Johnson's etc, just the same as D76 was made by every company 30 years later.

Ian

[RidingWaves]

Hmm. Why does the formula call for citric acid? Do you think I could subsitute Ascorbic Acid for the Hydroquinone, making a p-Aminophenol/Vit C warm tone paper developer?

[Photo Engineer]

That high level of sulfite and high level of bromide might do some nasty things to modern chloride papers. IDK for sure, but I would suggest a test first. It would certainly be good with Bromide or Br/I materials.

PE

[Ian Grant]

Hmm. Why does the formula call for citric acid? Do you think I could subsitute Ascorbic Acid for the Hydroquinone, making a p-Aminophenol/Vit C warm tone paper developer?

Citric Acid is used in quite a few warm tone developers, so must serve a purpose so adding Ascorbic instead would probably have the wrong & possibly an opposite effect.

My Bible (L.P. Clerc) is still in the UK as it's rather heavy but I think he'd explain why it's used.

That high level of sulfite and high level of bromide might do some nasty things to modern chloride papers. IDK for sure, but I would suggest a test first. It would certainly be good with Bromide or Br/I materials.
PE

Once diluted the levels of Sulphite &b Bromide are more typical of other developers.

Ian

[Photo Engineer]

Ian;

Sorry, it may seem that way. Look at the bromide though. That is over 1.2 g/ 100 ml of the mix. (12 ml of 10% = 1.2 grams in 100 ml + bromide in part A = 12+ grams in 1 L. of working solution).

For Sulfite it works out to about 22 grams of Sulfite / L coming from part A + the Rodinol contribution of about 5+ g/L at an estimate.

These just seem high to me for a paper developer. looks fine for a film developer though.

PE