The DARKROOM COOKBOOK, Third Edition

124 THE DARKROOM COOKBOOK
Cutting and Proportional Reducers
Cutting and proportional reducers are the most common types used. While there are about
a dozen or so formulas available, the most widely used is Howard Farmer’s formula, which
dates to 1883. The ingredients are easy to obtain in almost any part of the world, the process
is almost foolproof from the chemical angle, and the results are permanent.
There are dozens of published formulas claiming to be Farmer’s Reducer. The actual
makeup is fl exible, with the two main ingredients being potassium ferricyanide and sodium
thiosulfate (hypo). The quantity of ferricyanide used determines the strength of the solution,
so the amount of hypo is fl exible.
Farmer’s Reducer may be used as a single- or two-solution formula. The single solution
gives cutting reduction, that is, it reduces the shadows fi rst, then the highlights; this method
corrects for overexposure. The two-solution method works by treating the negative in a ferricyanide
solution fi rst, then in a separate solution of hypo. This method is proportional, giving
reduction in the highlights and shadows in proportion to the amount of metallic silver that
has been formed during development correcting for overdevelopment.
Before attempting to reduce any negative, you should fi x and wash it thoroughly. If an
acid fi xer is used it should include hardener. Also, reduce only one negative, or strip of negatives,
at a time. Following reduction the negative should always be washed thoroughly and
handled carefully before drying.
Super-Proportional Reducers
Super-proportional reducers have the property of reducing the denser parts of the negative
in preference to the middle tones and shadows. Ammonium persulfate is able to do this particularly
well. However, ammonium persulfate is notably subject to deterioration and is easily
affected by other substances. Therefore, the use of potassium persulfate, as in Kodak R-15, is
recommended.
Print Reduction (Bleaching)
Print reduction is perhaps the best all-around after treatment and is a technique that should
be known to all photographers. Among photographers, print reduction is commonly known
as bleaching and will be referred to as that in the Cookbook. However, it should not be
confused with true bleaching, also known as rehalogenation or rebromination, by which a
developed silver image is converted back to silver bromide (Formulas: Print Reducers: Print
Rehalogenating Bleach).
There are three methods for bleaching prints: overall, local, and spot.
1. Overall: The print is completely immersed in the reducing solution. This is excellent for brightening
the print and increasing overall contrast.
2. Local: This is the method for control work on comparatively large areas. Bleaching is done with
a small wad of cotton or a brush. Local reduction can brighten specifi c areas, put luminosity into
shadows, or drastically alter tonal values.
3. Spot: This is the way to eliminate black spots, place catch lights in eyes, or when precise control is
necessary. The bleach is applied with a spotting brush or toothpick.