In response to requests to put in one place the formulas we use in the darkroom,
we are posting them here. Fuller information on their use can be found in the
various articles.
DEVELOPING NEGATIVES
Formulas from Michael A. Smith and Paula Chamlee
| ABC Pyro |
| Solution A |
| Water |
900 cc |
| Sodium Bisulfite |
10 g. |
| Potassium Bromide (10% Solution) |
11 cc |
| Pyro |
60 g. |
| Water to make |
1,000 cc (One liter) |
| Mix at 100 degrees |
| |
| Solution B |
| Water |
900 cc |
| Sodium Sulfite |
105 g |
| Water to make |
1,000 cc (One liter) |
Mix at room temperature. Solution B keeps less well than solution
A or C. You might want to mix it shortly before use to insure
consistent results.
|
| |
| Solution C |
| Water |
900 cc |
| Sodium Carbonate |
80 g |
| Water to make |
1,000 cc (One liter) |
| Mix at 100 degrees |
For use: 1-1-1-7 (the 7 parts is water)
For subjects with extreme contrast use: 2-1-1-15
We develop by inspection and generally start looking at 8 minutes.
All films will vary in this regard.
| To mix a 10 % solution of Potassium Bromide (KBr) |
| Water |
400 cc |
| KBr |
50 g |
| Water to make |
500 cc |
Stop Bath
28% Acetic Acid 100 cc per each 1/2 gallon of water
Use for about 30 seconds
| To make close to one gallon of 28% Acetic Acid from 99.5% Glacial Acetic Acid |
| Water |
64 ounces |
| Glacial Acetic Acid |
33 ounces |
| Water |
24 ounces |
| Mix this outside. DO NOT breathe fumes from Glacial Acetic Acid. |
Fixer
Rapid Fix without hardener for 4 minutes
We then use Perma Wash for 5 minutes and follow with a 30-minute wash
PRINTING
Developer: Amidol for use with Azo. Mix at room temperature just before use.
| |
One liter |
1.5 liters |
3 liters |
4 liters |
| Water |
900 cc |
1,300 cc |
2,500 cc |
3,000 cc |
| Sodium Sulfite |
30 g |
45 g |
90 g |
120 g |
| Citric Acid |
3 g |
4.5 g |
9 g |
12 g |
| KBr (10% solution) |
2 cc |
3.65 cc |
8 cc |
11 cc |
| Amidol |
8 g |
11 g |
20 g |
24 g |
| Water to make final amount. Develop for no more than one minute. |
Developer: Amidol for use with Enlarging Paper. Mix at room temperature just before use.
| |
One liter |
| Water |
900 cc |
| Sodium Sulfite |
30 g |
| Citric Acid |
3 g |
| KBr (10% solution) |
6 cc |
| BB Compond 1% solution (or Benzotriazole 1% solution) |
60 cc |
| Amidol |
8 g |
| Water to make |
1000 cc |
| Develop as long as needed (generally 2-3 minutes) |
Stop Bath
Acetic Acid 28% 100 cc per each 1/2 gallon of water
Use stop bath for 10 -15 seconds.
Fixer
32 ounces dry measure Sodium Thiosulfate Prismatic Rice
Crystals per each gallon of water. Mix at around 90 degrees.
We mix 10 gallons at a time as a stock solution.
For use:
To each 1/2 gallon of fixer
Add 25 g of Sodium Bisulfite.
Fix for 30 seconds. Turn on the light. Inspect print.
Fix additional 3,5 minutes (4 minutes total).
Second Fixer
Sodium Thiosulfate without bisulfite
Use for 4 minutes.
Toner
| Water |
128 ounces |
| Perma Wash |
3 ounces |
| Rapid Selenium Toner |
1 ounce |
| Use for 3 minutes. |
First Wash: 1/2 hour
Perma Wash
3 ounces Perma Wash to 1 gallon water.
Use 5 minutes.
Final Wash: One hour
Dry Prints face down on nylon drying screens.
Flatten Prints in dry mount press for 15 seconds.