A Guide to the Use of Photographic Developers
This guide offers a technical foundation for the employment of photographic developers, classifying the optimal pairings with the various films on the market so as to guarantee the finest rendering of contrast, grain and sharpness.
This guide accompanies the pairing table and is conceived to orient with clarity both the one who takes his first steps in analogue photography and the habitual frequenter of the darkroom. Our intent is to furnish a solid technical foundation for the employment of our developers, entrusting thereafter to personal judgement and practice the evaluation of the final result.
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Reading and Evaluation of Results: Our laboratory tests have permitted us to classify the interaction between the various films in commerce and our developers, dividing them into three categories of reliability:
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Certain Results (Green – Recommended):
The pairing between film and developer is chemically ideal. It guarantees a balanced contrast, a controlled grain, and a faithful rendering of tones. It is the choice of assured reliability, perfect for obtaining optimal negatives without surprises.
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Variable Results (Yellow – Possible):
The use of this developer is possible, but the final rendering shall depend greatly upon the accuracy of exposure and the quality of light at the moment of the shot. It is a pairing that requires greater skill, as it produces outcomes that may differ according to the conditions of the shoot.
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Uncertain Results (Red – Not Recommended):
The formula of the developer does not suit the structure of that particular film. We advise against this pairing as it may generate an excessive intrusion of grain or an undesired alteration of contrast.
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Substantial Differences Among the Developers:
Following the same order as the synoptic table, we set forth the characteristics of each developer, that the operator may make a right choice according to the film employed and the result desired.
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N. 17 (Kodak D-17):
This developer proves itself of excellence in extracting the utmost fidelity and cleanliness of the latent image on slow films of classic grain, and permits the treatment of large volumes and considerable quantities of film by regenerating the bath. Its use upon modern high-sensitivity films is, however, to be discouraged, for the structure of such emulsions ill suits this formula, producing uncertain results.
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N. 19 (Kodak D-19):
A preparation of notable energy, it renders a fine grain united with a high contrast. It shows itself exceedingly tolerant of the processes of forced elevation of sensitivity (push processing), bearing increases of up to two stops without decay of the image.
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N. 23 (Kodak D-23): A developer of soft nature, recommended when the operator desires to obtain a fine grain and a low contrast. Its formulation reveals itself the ideal employment for extending the dynamic range of the negative.
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N. 76 (Kodak D-76):
A developer of universal application and sure reliance for the photographic practice. Its classic formula guarantees outcomes of proven excellence with the generality of films in commerce, without substantial distinction between modern and classic emulsions.
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MICROPHEN:
An excellent compensating preparation that assures the operator a fine grain united with a normal contrast. It distinguishes itself for the superb capacity to preserve a great richness of detail, alike in the deep shadows as in the high lights.
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DK-50:
A developer of classic mould, capable of rendering a medium-high contrast accompanied by fine grain. Its employment is most profitable, as it occasions no loss whatsoever of the film's nominal sensitivity.
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DIAFINE-2B:
A special preparation operating in two separate baths, conceived chiefly for those applications that require a marked hyper-compensating capacity. It acts upon the emulsions while marvellously maintaining the fineness of the grain unaltered.
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PYRO-HD:
This preparation for special applications represents a developer of supreme precision, devoted to rendering an elevated sharpness whilst maintaining unaltered the natural dimension of the grain. Its reaction generates a tanning contrast mask (of brown colour) which, in the printing phase, acts as a filter: it increases the density of the shadows and improves the overall contrast, guaranteeing a superb tonal richness.
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IP:
A preparation formulated specifically to tolerate the demanding processes of forced elevation of sensitivity (push processing). It grants the photographer an elevated image sharpness united with a high contrast, bearing increases of up to two stops without any loss of density in the shadows.
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POTA:
A special bath devoted to the extreme lowering of contrast, exceedingly useful for the treatment of technical or scientific films, in order to render their tonal range conveniently printable.
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REVERSAL T:
A chemical formula of peculiar nature, prepared solely for the reversal process, so as to transform directly the exposed film into a positive slide fit for projection.
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We invite whosoever approaches these products to experiment, beginning always from the recommended combinations, noting with care the times and temperatures employed.