Product Description
Four (4) Pyrogallic Acid (Pyro) Developer Formulas
Pyrogallic Acid developers, commonly referred to as Pyro or pyrogallol, have been enjoying a renaissance among large format photographers working with alternate processes. Dating back to 1851, Pyro - a staining developer - is one of the earliest developing formulas in photography, and its legendary status can be largely attributed to its exclusive use by one of the icons of large format photography, Edward Weston, who used a variation of the A. B. C. Pyro formula detailed below.
On August 24, 1924, Weston noted: “I have returned, after several years’ use of Metol-Hydroquinone open-tank developer, to a three-solution Pyro developer, and I develop one at a time in a tray, instead of a dozen in a tank!” This technique he used for the rest of his life. It is classic; he undoubtedly learned of it at the “photographic college” he briefly attended. The 1908 instruction manual of a similar institution — the American School of Art and Photography — recommends it as the standard developer. Weston used it with less than the usual amount of sodium carbonate. (Interestingly, the Wollensak Optical Co. advised: “Negatives made with the Verito should be fully timed, and slightly underdeveloped, using any standard developer with a minimum amount of carbonate of soda. . .”)
— From The Daybooks of Edward Weston, Foreword by Beaumont Newhall
This free download includes the following four (4) Pyro Developer Formulas:
Standard A. B. C. Pyro Developer [Formula D-1]
For Warm Tones Using Tank or Tray
Stock Solution A
Avoirdupois
Metric
Sodium Bisulphite (E.K.Co.)
140 grains
9.8 grams
Pyro
2 ounces
60.0 grams
Potassium Bromide
16 grains
1.1 grams
Water to make
32 ounces
1.0 liter
Stock Solution B
Water
32 ounces
1.0 liter
Sodium Sulphite, desiccated (E.K.Co.)
3½ ounces
105.0 grams
Stock Solution C
Water
32 ounces
1.0 liter
Sodium Carbonate, desiccated (E.K.Co.)
2½ ounces
75.0 grams
Dissolve chemicals in the order given.
Prepare fresh developer for each batch
For tank development, take 9 ounces each (285 cc.) of A, B and C and add water to make 1 gallon (4 liters). For the 3-1/2-gallon tank take 32 ounces each of A, B and C and add water to make 3-1/2 gallons. Develop for about 12 minutes at a temperature of 65° F. (18° C.). Any scum that may form on the surface of the developer must be removed by means of a sheet of blotting paper before developing films.
For tray development, take 1 ounce (30 cc.) each of A, B and C and add 7 ounces (210 cc.) of water. Develop about 5 to 7 minutes at 65° F. (18° C.).
An instruction card packed in each box of Panchromatic Film or Plates gives the correct time of development, at varying temperatures, for that particular emulsion.
Two-Solution Pyro Tray Developer [Formula D-90]
Stock Solution A
Avoirdupois
Metric
Sodium Sulphite, desiccated (E.K. Co.)
2 oz. 145 grains
70.0 grams
Sodium Bisulphite, (E.K. Co.)
245 grains
17.0 grams
Pyro
285 grains
20.0 grams
Water to make
32 ounces
1.0 liter
Stock Solution B
Sodium Carbonate, desiccated(E.K. Co.)
2½ ounces
75.0 grams
Potassium Bromide
15 grains
1.0 gram
Water
32 ounces
1.0 liter
Dissolve chemicals in the order given.
For average use take 1 part of Stock Solution A, 1 part of Stock Solution B, and 2 parts of water. Develop 4 to 6 minutes at 65° F. (18° C.). For greater contrast, use 1 part of A, 1 part of B, and 1 part of water; for less contrast, use 1 part of A, 1 part of B, and 4 parts of water.
Non-Staining Pyro Tray Developer [Formula D-84]
For Display Transparencies, Copy Negatives and Ciné Enlargements
Stock Solution A
Avoirdupois
Metric
Water
24 ounces
750.0 cc.
Sodium Sulphite, desiccated (E.K. Co.)
6 oz.
180.9 grams
Pyro
1 ounce
30.0 grams
Water to make
32 ounces
1.0 liter
Stock Solution B
Water
32 ounces
1.0 liter
Sodium Carbonate, desiccated(E.K. Co.)
4 ounces
120.0 grams
Potassium Bromide
55 grains
3.8 grams
Dissolve chemicals in the order given.
For use, take one part A, one part B and four parts water. Develop about four minutes at 65° F. (18° C.).
Some workers, who develop a large number of films every day, use large tanks and prefer a pyro developer that will keep for about two weeks. The following developer has good keeping qualities and will produce excellent negatives if kept up to normal strength:
Elon-Pyro Developer [Formula D-7]
For Tank or Tray Use
Stock Solution A
Avoirdupois
Metric
Water (about 125° F.) (52° C.)
16 ounces
500.0 cc.
Elon
¼ ounce
7.5 grams
Sodium Bisulphite (E.K.Co.)
¼ ounce
7.5 grams
Pyro
1 ounce
30.0 grams
Potassium Bromide
60 grains
4.2 grams
Cold Water to make
32 ounces
1.0 liter
Stock Solution B
Water
32 ounces
1.0 liter
Sodium Sulphite, desiccated (E.K.Co.)
5 ounces
150.0 grams
Stock Solution C
Water
32 ounces
1.0 liter
Sodium Carbonate, desiccated (E.K.Co.)
2½ ounces
75.0 grams
Dissolve chemicals in the order given.
For tank development, take 8 ounces (250 cc.) each of A, B and C and add water to make one gallon (4 liters). At a temperature of 65° F. (18° (1.), development time is from 9 to 12 minutes. This developer can be used repeatedly for two or three weeks if kept up to its normal strength by adding fresh developer in the proportion of 2 ounces (64 cc.) each of A, B and C to 8 ounces (250 cc.) of water.
For tray development, take 2 ounces (64 cc.) each of the A, B and C solutions to 16 ounces (500 cc.) of water. Develop about 7 to 9 minutes at 65° F. (18° C.).
All tank developers must be kept covered with a floating lid or paraffin paper floated on the solution to prevent aerial oxidation.
An historic glass plate negative showing staining common for pyrogallol development.
