Pyro and Pyrocatechin developers | Pictorial Planet

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From the author of "The Art of Black and White Developing"

Pyro and Pyrocatechin Developers

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Pyro (pyrogallol) and Pyrocatechin based developers are some of the best you'll ever use. Re-invigorated since the 90's by great formulators such as Gordon Hutchings (PMK), Sandy King (Pyrocat-HD), John Wimberley (WD2D) and Barry Thornton (Dixactol Ultra etc.) to name a few. If you're serious about getting the very best from your negatives this could be the way to go.

Pyrogallol and pyrocatechin are two developing agents that have been used for over 100 years. They have high acutance and local contrast control through staining and they harden the gelatine in the emulsion (this helps solidify and protect the film emulsion from damage such as scratches). The hardened gelatin might also stop the movement of dissolved silver, lessening the re-plating action of the Sodium Sulphite, keeping the grain sharp.

I talk at length about these developers in my book but here's an example by Barry Thornton, his Pyrocatechin Two Bath developer, possibly the pre-cursor to his remarkable Dixactol commercial developer.

Bath A Stock solution:
Pyrocatechin 10g
Sod. Sulphite 2g
Pot. Bromide 0.5g
Water to make 100ml

Bath B Stock solution:
Pot. Hydroxide 10g
Pot. Bromide 0.5g
Water to make 100ml


Working solutions of A and B are made by mixing each separately 1+14 with water. 
Recommended times: 4 minutes in A at 21° C with agitation once every 30 seconds, followed by 4 minutes in B at 21° C with agitation once every minute.

Do not rinse between baths.

I like two bath developers as they lend a hand in controlling contrasty scenes while developing normal scenes to completion. But the genius of the above developer is that it also uses the local contrast control of the pyrocatechin to help even more.

Why not give it a try and let me know how you get on. Write your comments below.

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