Any chemists out there?

[pete_andrews]

All the questions about Pyro and Chromogenic films like XP2 have set me thinking (dangerous!). }:^)

 

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There seems to be no reason why a colour coupler can't be introduced at the developing stage for <i>any</i> black and white film, to give a stain like Pyro, but without the variability.

 

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Are there any Chemists out there who could name a few substances that colour-couple with PPD derivative developers, to give a red, yellow or neutral stain? How easy are they to come by? Cost, toxicity, etc?

 

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Thanks.

[ed b.]

If I'm not mistaken, that is pretty much the way the Kodachrome

process works. This kind of question needs to be addressed to Robert

Chapman of Photo Techniques magazine--he's the only person I know of

who could answer it authoritatively.

[tony_brent]

That's exactly how dye transfer color prints work. The separation negs

are developed in a tanning developer and then dyed. The dye "takes" in

relation to the depth of the tanned image. Kodachrome uses the same

principle, only it does it all on one film base.

[peter_hughes2]

Tony -- one small correction: the matricies, not the seps, are

developed in tanning developer. Then the 3 dyed "mats" are rolled

onto a receiving sheet, one at a time.

 

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http://www.ravenvision.com/peterhughes.htm