The
PMK formula is designed as a universal developer for a wide variety of modern
emulsions used under diverse conditions. PMK stands for Pyro- Metol- Kodalk. Kodak has changed the name Kodalk to Balanced Alkali, this is their proprietary name for sodium metaborate. The formula is constituted to achieve the best
overall results in consideration of the following technical criteria:
sharpness, maximum image stain, minimum general stain, edge effects, film
speed, flexibility for the Zone System plus and minus development, stability,
consistency, convenience of use and long shelf life.
FOR YOUR CHEMICAL SAFETY
All chemicals are dangerous and must be treated with respect. Please read the
warnings listed here. Always use rubber gloves and dust mask when using
chemicals.
METOL,. Some individuals become sensitized (develop allergic symptoms or
rashes) while using Metol. If this should occur, discontinue use and consult a
physician.
PYROGALLOL,. Pyro is quite toxic and is readily absorbed through the lungs, skin
and mouth. Pyro is also a phenol and has the potential to cause skin burns. To
be on the sate side please use rubber gloves and keep your work area clean with
lots of soap and water. Brief contact with the skin will cause darkening which
is not a chemical burn. Prolonged skin contact will cause a chemical burn which
closely resembles a heat burn. Pyro is also very dusty, work in a well
ventilated area. Do not inhale its dust. Keep containers tightly closed and
away from light.
KEEP AWAY PROM CHILDREN.
FIRST AID: If
contact is made, flush with water. If extensive contact is made or if in eyes,
consult a physician. If inhaled or swallowed, get medical attention at once.
STOCK SOLUTION A: It is
advisable to use distilled water, but high, quality filtered tap water can be used. Use room temperature water. Take a small finger pinch of sodium bisulfite and add it to the water for the Solution A. Add the
Metol to Solution A, and stir until it is dissolved completely. Add the
remaining sodium bisulfite and stir until dissolved. Add the Pyro to the stock
solution outside or under a ventilating hood. Stir until the pyro is disolved
completely.
STOCK SOLUTION A
|
Chemical |
Amount |
Units |
|
Distilled Water
(75°F) |
400 |
ml |
|
5 |
g |
|
|
10 |
g |
|
|
50 |
g |
|
|
Water to make |
500 |
ml |
STOCK SOLUTION B: Distilled
water is a MUST for solution B. This solution is highly concentrated and a
considerable quantity of the sodium metaborate may precipitate if the water is not pure. Dissolve the sodium metaborate at room temperature in distilled water. Any residual amount of this chemical will dissolve by itself after 24
hours. The small amount of residual left will not affect the solution activity
even if used immediately.
STOCK SOLUTION B
|
Chemical |
Amount |
Units |
|
Distilled Water
(75°F) |
400 |
ml |
|
300 |
g |
|
|
Water to make |
1000 |
ml |
SHELF LIFE
The shelf life of the stock solution is indefinite. Partially filled and
stoppered bottles will last for years. Always use glass bottles for the storage
of developer solutions. Clear glass is fine for PMK, if stock Solution A is
kept out of strong light. After a week or two, the color of Stock Solution A
will turn a pale yellow color. This is the equilibrium point no further change
will occur.
WORKING SOLUTION OF PMK
1 Part A + 2 Parts B + 100 Parts of water.
Example: 10 ml A + 20 ml B + 1000 ml of water make approximately one liter or working solution. Measure the quantity
or water and add the A and B stock solutions. It does not matter witch is added
first.
Note: When PMK is mixed together, the solution will immediately proceed through
color changes from gray-green to pale amber. This is an important visual check
of solution activity. If there is no color change, something is wrong. Recheck
you stock solution.
FILM DEVELOPMENT TEMPERATURE
The conventional temperature for film development is 68°F/20°C. During the
summer month in many parts or the country, cold tap water is often much warmer than 70°F. To bring this temperature down with ice
cubes is inconvenient, to say the least. For PMK each degree of increase of
developer temperture, decrease the development time by 4%. Do not hesitate to
use the higher tempertures. With appropriate reduction in development time, no
loss of quality in the negative will result.
STOP AND FIXING BATHS
A plain water stop bath is excellent for all normal films and
developers. Use a large volume or water and agitate roll and sheet film continuously. We recommend using our Photographers' Formulary TF-4 non-acidic fixer (Cat. No. 03-0141), since fixers with hardening agent will decrease the
image stain, therefor, the use of non-hardening fixers is necessary. Do not use
Photographers' Formulary TF-4 with an
acid stop bath. Do not exceed the manufacturers recommended fixing time.
PYRO AFTER BATH
Place all negatives, direct from fixer, into the used developer for two
minutes. Agitate every 30 seconds. The alkali after bath induces the formation
of stain in the developed negative. An alternative alkaline after bath can be
used if desired. The use of 5 grams of sodium metaborate per liter of water is the alternative.
FINAL WASH
Wash the film running water for 20-30 minutes. Wash all films for at least 20
minutes. The image stain increases during the wash cycle.
DEVELOPMENT TIMES
THESE ARE STARTING TIMES. PLEASE DO TESTING BEFORE DEVELOPING NON-REPLACEABLE
FILMS.
|
Ilford
Film |
70°F |
80°F |
|
FP4
EI=160 |
12 min. |
7 min. |
|
HP5
EI=400 |
13 min. |
8 min. |
|
PAN F
EI=32 |
9 min. |
NR |
For
35 mm, HP5 Plus, try EI=320 & 12 min. at 70°F.
For Ilford Pan-F, 35mm, normal strength PMK is fine, try 7-1/2 at 70°F.
For Ilford Pan-F, 120 roll film, reduce solution B by 25%.
|
Kodak Film |
70°F |
|
Tri-X EI=260 |
14 min. |
|
T-Max 100
EI=100 |
12 min. |
|
T-Max 400
EI=400 |
15 min. |
Kodak
T-Max 100 and T-Max 400 are extremely sensitive to development time and
temperature. Carefully control the development time and use a temperature
controlled water bath, if possible. Kodak T-Max 100 appears to have a
large amount of anti-inhalation dye. This dye must be removed or shadow
separation and image clarity will suffer. Kodak recommends that the developed
and fixed negatives receive an additional bath in fresh fixer to remove any
anti-halation dye. Photographers' Formulary TF-4 Fixer will
remove this dye.
For T-Max P3200, try EI of 3200 and PMK for 10-12 min. at 80°F.
|
Agfa Films |
70°F |
|
AP-25 EI=16 |
11 min. |
|
AP-100
EI=80 |
14 min. |
|
AP-400
EI=200 |
16 min. |
For
Agfapan 100 roll film, try EI of 100 and 11 minutes.
|
Bergger 4x5 Sheet Film |
70°F |
|
BPF200
EI=100 |
11 min. |
|
Forte Film |
70°F |
|
Forte200 EI=100 |
12 min. |
|
Forte400 EI=200 |
15 min. |
REFERENCE
PMK Film Developer, Kit No. 01-5050, Photographers' Formulary (800-922-5255).
Pyro Tips, Maxim M. Muir,
Lotus View Camera, John Horowy, 815-282-9876, http://www.lotusviewcamera.at/
Bergger and Forte Film, Freestyles Sales Co.http://www.freestylesalesco.com/
PMK Film Developer, The Film Developing Cookbook, Stephen G. Anchell
and Bill Troop, p. 76
Gordon Hutching's PMK Formula, The Darkroom Cookbook, Second
Edition, Stephen G. Anchell,
p.174.
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