Wolfgang Moersch Photochemie
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Polychrome development Part 3: Suitable papers for polychrome development
Suitable papers for polychrome development and their varying reactions to toning in Selenium and Polysulfide.

In the following examples all papers were developed in identical developer dilutions. The only differences were exposure times and the developing times needed for the first developer.

This infrared negative is an example for a high contrast range. The developer was Tanol Speed. Silver density alone is around 1.46 logD! Silver density + stain result in too high a contrast range for blue sensitive graded papers processed conventionally. A print on grade 1 would look as if printed on grade 4 or 5. Such "unprintable" negatives turn unproblematic using Polychrome technique controlling the result via the quantity of light and the duration of dwell in each of the two differently working developers.

Fomatone 132

Fomatone 132 MT1 Selenium toner 1+25 4 minutes

Fomatone 132 MT4 Siena Polysulphide Toner 1+25 40 seconds

Kentmere VC warm tone

Noncompetitively and just for comparison:
the old cadmium containing emulsion of Kentmere Kentona without toning.

Kentmere Kentona

Kentmere Kentona MT1 selenium toner 1+25 2 minutes

Kentmere Kentona MT4 Siena Polysluphide toner 1+25 1 minute

Forte PW14 - Select VC - Bergger Prestige - Adox Polywarmton MT1 Selenium 1+25 2:30 minutes

Fomabrom Variant III

A stronger developer solution should have been used for this paper. The 6 minutes it took to darken the deep shadows was already too long in comparison to the other papers. In contrast to Fomatone, which is not a sensitive paper at all, overexposure time had to be tripled. As a result the highlights appear obscure. To clear the white areas the highlights were reduced (by mild bleaching and then fixing).

Fomabrom Variant III MT1 Selenium 1+25 5 minutes

Of course, bleaching the highlights also removed the base fog, which is causal for an intensive hue. As is known, pure bromide silver emulsions react slower to selenium toning than emulsions containing a mixture. Using a dilution of 1+25 not much is happening even after five minutes.

Fomabrom Variant III MT1 Selenium 1+6 4 minutes