Has anyone tried Hydroquinone instead of Pyrocat in the Pyrocat HD [the normal version]. I read at one stage that they could be substituted 1 for 1 as they are from a similar chemical family. I think it was Pat Gainer [APUG] who was suggesting that could be done. I wonder if it would be a similar developer, or if anyone has tried it? I can get the Hydroquinone but not the Catchetol [?]
Steve
Hydroquinone doesn't act in the same way as Pyrocatechin, it only has very mild tanning /staining properties.
Pyrocatechin on it's own works as a surface developer as in the Windisch compensating formula, because it tans and hardens film proportionally to the amount of exposure & development.
Yes you could substitute Hydroquinone for the Pyrocatechin but you'd get a developer that had very few or little of the beneficial attributes that make Pyrocat such a good developer.
A better substitution would be Pyrogallol but it has a tendency to oxidise faster.
Try looking for Pyrocatechin by it's different names, Pyrocatechol, Catechol, 1,2-dihydroxybenzene it's used outside Photography so should be available from a good chemical suppliers.
Ian
You are always a great source of knowledge, thanks as always Ian
Steve,
Ilford DDX developer contains Hydroquinone and Phenidone as the reducing agents.
I used DDX for many years and had difficulty controlling development of the highlights.
Switching to Pyrocat-HD solved the problem.
Perhaps the Photographer's Formulary can ship Pyrocat-HD (in Glycol) to Australia.
www.photoformulary.com
Steve
I have tried to replace Catechol with Hydroquinone. With very little sulfite or ascorbic acid produces an intense yellow mask. The problem could not solve was that hydroquinone is a strong developing agent at a pH of more than 10 or 11. Long time to start developing and then makes a breakthrough infection to achieve maximum density of the negative. Produces a large edge effect (high apparent sharpness), but it was uncontrollable for me.
Claudio Sz
I tested the "formula" that I had substituted but like Gem and Claudio the highlights were very difficult to control. The rain has stopped so I will return to something that is working correctly.
At least one person seems to do it successfully http://www.apug.org/forums/viewpost.php?p=146256Has anyone tried Hydroquinone instead of Pyrocat in the Pyrocat HD [the normal version].
I've just mixed some up to try with x-ray film but I have no experience with staining developers to compare it to.
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