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Jack Fulton
Paraminophenol (Rodinal) Film Developer
A P-Aminophenol Hydrochloride film developer for that is economical and
excellent for slower speed films (ISO 32-200). Unless graininess is
desired, this developer is not recommended for faster films. This
developer produces medium-grain negatives with good sharpness. The
contrast is variable and depends upon dilution and development times.
The chemicals are used to prepare a stock solution, which is diluted
1:50 or 1:100 to obtain the working solution. One liter of stock
solution yields 50 to 100 liters of working solution. The shelf life of
the stock solution is about 6 months. The working solution is used once
and then discarded.
MIXING THE STOCK SOLUTION
SOLUTION A
Water 625 ml
P-Aminophenol Hydrochloride 50 g
Sodium metabisulfite 150 g
Boil the water and cool 5 minutes. Add a few crystals of metabisulfite
from the total called for. Then add the p-aminophenol hydrochloride and
the rest of the metabisulfite.
SOLUTION B
Potassium hydroxide 215 g
Cold water (68°F/20°C) to make 500 ml
This solution must be prepared in a sink and in a well ventilated
area. Place a dry plastic mixing bowl in a sink and place the solid
potassium hydroxide in the bowl. Measure out 350ml of cold water and
carefully add the water to the container. Stir the mixture with a
plastic spoon until the solid has gone into solution. Stir gently and
avoid splashing the solution. Add cold water to make 500 ml of solution.
When potassium hydroxide goes into solution, considerable heat is
generated. If your water was not cold enough, the solution may start to
steam. If this should occur, add some ice to cool the solution. DO NOT
BREATH THE VAPOR. If the solution starts to steam and you cannot cool
it, leave the room and let it cool off by itself. After the solid has
gone into solution, let the solution sit until it reaches room
temperature. Using a plastic funnel, transfer the solid potassium
hydroxide solution to its plastic storage container. The transfer should
be carried out in the sink. Add sufficient cold water to make 100 ml
using a portion of the water to rinse out the mixing bowl. Before any of
the mixing equipment leaves the sink, rinse and wash with cold water
until you are positive that no residual hydroxide remains. Be sure to
wash the outside of the storage container before you remove it from the
sink. Should any of this solution be spilled on your skin, wash
immediately with cold water followed by soap and water.
To the above solution A, slowly add about 180ml of solution B while
stirring. A precipitate will form. As the B solution is added, the
precipitate will dissolve. The object is to add just enough Solution B
to nearly, but not quite, dissolve the precipitate. A few traces must be
left. When this is done, add cold water to make 1 liter of stock
solution.
USAGE
This versatile developer can be used in varity of ways and adapted to
very slow, fine grain films or with the fast ISO 400 or 500 films.
Slow Films: For low contrast subjects where you need to build contrast
dilute 1:75 and develop 12 to 15 minutes. Dilute 1:100 and develop for
68°F/20°C the same time for normal contrast subjects. To soften, reduce
the 68°F/20°C time in the 1:100 dilution to 8 to 12 minutes.
Fast Films: For increased contrast develop 12 to 15 minutes at 1:50.
For reduced contrast develop 12 to 15 minutes at 1:100 68°F/20°C. For
normal contrast develop about 12 minutes at 1:75 68°F/20°C.
NOTES
This is not a fine grain formula, although it will deliver extremely
high acutance and can be either compensating or pictorial as needed.
With faster films the grain will be quite course. This can be avoided by
using 9% sodium sulfite solution to dilute the stock developer. The
sulfite. which acts as a silver solvent at this concentration, will
reduce grain size (and at the same time impair acutance, though a good
balance can be struck.) A typical developing time of 11 minutes at 1:75
(sulfite) at 68°F/20°C with Tri-X is common, but it could easily be half
that or higher than that, depending on individual circumstances. If your
negatives are consistantly too contrasty, reduce the development time or
increase the dilution of the developer. If your negatives are
consistantly tosoft, increase the devoloping time or reduce the
dilution. Many such controls are available with this formula, and may
result in negatives of exceptionally high quailty.
REFERENCE
Paraminophenolate (Rodinol Type) Film Developer, Kit No. 01-0180,
Photographers’ Formulary, 1-800-922-5255.
Photo Lab Index, Supplement No. 185, Section 8, p.341
p-AMINOPHENOL
Other names: p-Hydroxyaniline; 4-amino-1-hydroxybenzene;
4-amino-phenol; paramidophenol; and a number of trade names (Citol,
Kodelon, Energol, Freedol, Indianol, Kathol, Para, and Unal) for salts
of this compound.
Properties: The hydrochloride salt is a white crystalline powder that
slowly darkens in air. The hydrochloride salt dissolves to the extent of
3% at 60°F but only 0.3% in a 5% sodium sulfite solution. Solubility is
10 grams in 100 ml aqueous solution at 20°C and also soluble in alcohol.
The salt has high solubility in strong alkali (sodium hydroxide), making
possible the Rodinal type of developer (also sold under trade names of
Azol, Activol, Artinal, Kalogen, and Paranol).
Precautions: These compounds are irritants, causing skin
sensitization, dermatitis, and, if inhaled, asthma. Avoid prolonged
exposure and contact with the eyes, skin, and mucous membranes. Store in
air-tight containers and away from exposure to air and light. Use with
adequate ventilation and do not breathe dust or vapor from heated
solutions, Wear safety glasses and rubber gloves during handling. Wash
thoroughly after handling.
First Aid: In case of contact, flush eyes or skin with plenty of
water. Remove contaminated clothing and wash before reuse. If inhaled or
swallowed, immediately call a physician for treatment.
Uses: As a developing agent in normal and concentrated developers.