CPD
Hello!
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Can anyone tell me where I can buy Pinakryptol (in household-sized packs)?
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Bye!
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jochen53
Hello,
you’re going to have a problem there. As far as I know, desensitising dyes are no longer manufactured. If you search on Google, you’ll find plenty of Chinese companies claiming to be able to supply them, but when you actually enquire, you get no reply. There seems to be a supplier of pinacryptol yellow in the US, but they’re asking €70 for 1 g! If you want to search by CAS registry number or name, they are: 19220-17-4: (phenazinium, 1,3-diamino-5-phenyl-, chloride (8CI, 9CI); 1,3-diamino-5-phenylphenazinium chloride; Pinacryptol Green; Pynacryptol Green)
CPD
Hello Jochen!
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Thank you very much for your advice! I might have a supplier from September onwards – the company is currently on holiday.
jochen53
Hello,
Incidentally, desensitising dyes don’t work with all developing agents. I read something about this in Spärl and Weizcker’s *Fotographisches Rezeptbuch*.
CPD
Hello Jochen!
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Thank you very much for pointing that out! I wasn’t aware of this incompatibility with certain types of developers!
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Do you have any other references on Pinakryptol? It seems to be a largely forgotten process.
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I’ve now been given a source for Pinakryptol Yellow. As mentioned above, I’m expecting to hear in September whether Pinakryptol Green is available. However, I have no idea how the individual Pina colorants differ in their use as desensitisers.
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I’d be interested to know how this desensitisation works in the first place! Is some sort of filter incorporated into the emulsion? Anyway, the process seems to have been known even when Panchromatic emulsions first appeared. The Lüppo-Cramer process?
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In American forums, a few people report on their Duka work using an IR viewing device. It seems you actually end up with a fairly bright Duka. The only downside is the heavy weight, and perhaps also that you look like the character from The Silence of the Lambs.
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Best regards
jochen53
Hello,
You can find information on this subject in: Josef Maria Eder, "Recipes, Tables" (1949); reprinted by Lindemanns Verlag, pp. 40–42; or: Eder and Löp-po-Cramer in Vol. III, “Ausführliches Handbuch der Photographie”, Halle (1932) under the heading “desensitisation”, or: Spärl/Weizsäcker, Fotografisches Rezeptbuch, Knapp 1964). Pina Green is incompatible with pyrogallol and hydroquinone. Development time is extended by approx. 1/3. Stock solution: 1 g to 500 ml water. Either use it as a pre-bath for 2–3 minutes in a 1:9 dilution, or add 50 ml to 1 litre of developer; switch on the Duka light (light green) only after some time has elapsed.
Pina Yellow can only be used as a pre-bath; it is incompatible with sulphite. Stock solution: 1 g to 200 ml water, dilution 1:10.
Pina White from I.G. Farben/AGFA could also be used as a pre-bath or developer additive and was sold in tablet form; alternatively, 1 g + 30 g sodium sulphite to 1000 ml water as a pre-bath or 1 g dissolved in 15–20 ml water to 1 l developer.
You can find information on the theory of sensitisation in the three-volume work by Jost Marchesi (a rather complicated explanation involving the ‘ribbon model’).
CPD
Hello Jochen!
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Thank you so much for your detailed and helpful advice!
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Best regards!
ZalmanYanowsky
Aesthetic concerns about the character in *The Silence of the Lambs* – brilliant!
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Best regards, Zal
