Google Wiki Pedia: 4.1 Ilford FP4+ film: High definition development

Sunday, 26 June 2011

4.1 Ilford FP4+ film: High definition development

Ilford FP4+ is one of the available black and white film emulsions available in the Whole Plate format on an annual basis from Ilford Harmon suppliers and partners.

As a traditional classic silver grain emulsion (differentiated from later tabular or cubic grain emulsions), Ilford FP4+ is favoured for its tonality when applied for silver gelatin printing as well as pyro[catechol or -gallol] development.

The most often cited rationale for photographers switching to tabular grain emulsions relates to the smaller grain size or image definition which tabular grain affords. For contact printing of whole plate negatives i.e. 1:1 reproduction, grain size is no longer an issue yet while image definition and tonality gain priority.

To briefly recapitulate:

Metol based developers [Fuji Microfine; Ilford Perceptol; Kodak Microdol] dissolve grain structure, thus diminishing grain size however reducing perceived sharpness related to 'definition' and 'acutance'.

Acutance developers like Rodinal increase perceived sharpness and definition at the expense of grain.

Pyrocatechol and pyrogallol type developers mask grain by staining the negatives. This also increases the dynamic range of tone rendition however the tonal expansion can create problems for silver gelatin fibre printing.

Paterson FX39 & Ilford FP4+

Other developer combinations exist. Of these, the highest definition developer is the traditional Paterson FX39, now marketed by Ilford Harmon, the suppliers of Ilford FP4+ whole plate film. Paterson FX39 was originally intended for high defintion development of tabular grain i.e. modern emulsions. Its definition is reported to be higher than Rodinal without the ensuing graininess associated with Rodinal. Since its reintroduction into the market in 2007, it has rapidly become my preferred universal developer for its tonal rendition. There are significant limitations with FX39 which has perhaps precluded its popularity worldwide.

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