J.W.Shaw - Hydroquinone p-Aminophenol Developer
Warm Toned Print developer. (Using Rodinal)
Hydroquinone 16.7 g
Sodium Sulphite 91 g
Citric Acid 6.25 g
Potassium Bromide 3.12 g
Water to 1 litre
Sodium Hydroxide 16.7 g
Water to 1 litre
Solution C Potassium Bromide Solution 10% (!00 g/litre)
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.
What's in the rodinal that makes it necessary to add to this developer mixture?
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.
Oke, that's interesting, thanks for clarifying!
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.
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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.
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?
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.
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.
Originally Posted by RidingWaves
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.
Once diluted the levels of Sulphite &b Bromide are more typical of other developers.
Originally Posted by Photo Engineer
Last edited by Ian Grant; 08-03-2009 at 05:19 PM. Click to view previous post history.
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.