Photographic Formulae and Notes 10/8/18

(C) b-wtechnik.pp7.uk

The objective is to :

1. Use low cost readily available chemicals equivalent to photographic grades where required.
    Most of the chemicals below are essentially common food grade E numbers.
2. Use simple formulae that have excellent keeping properties and are easy and quick to prepare
3. Have a minimum effect on the environment

The approximate costs shown relate to the purchase of small quantities i.e. 500g - 1000g except for
developing agents which assume 100g quantities.

UNLESS STATED, ALL SOLUTIONS ARE TO MAKE 1 litre

Water Softeners (Stops water hardness precipitating out in alkaline solutions)

W001    EDTA Softened water.

pH should be close to 7 therefore will not upset the pH of weak developers.

W002    STPP Softened water

May be used for the preparation of all other solutions, however, after a period of time,
it loses its effectiveness in alkaline solutions and so should only be used in one shot applications.
STPP on its own increases the alkalinity of the solution which may be a problem in weak developers.

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Use softened water for the preparation of all other processing
solutions in particular alkaline ones.
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FD003    ID11 Fine Grain Developer

The standard high sulphite fine grain developer with no speed loss.
Development times are often too short with stock solution.
Can be used 1 + 1 dilution with little degradation.

FD004    ID11b, Buffered Version

Preferred for use at 1 + 1 dilution while maintaining film characteristics.
Development times are in between Stock and 1+1 ID11.
Maintains macro and micro pH during development.

PD005    Dektol Paper Developer

Use at either 1 + 2 or 1 + 3 dilution.

S006    A Buffered Citric Acid Stop Bath

Citric acid is 15 times stronger than acetic acid which will give a pH less than 4 on its own.
If this is a concern, add the sodium citrate. The metabisulphite suppresses growths of organisms.
Without it black things float on the top after a few weeks. This is meant as a one shot solution anyway.
The choice is yours.

S007    A Buffered Neutral Stop Bath

This will arrest film development as quickly as a normal acid stop bath and is intended to
be used with alkaline or neutral fixers. Use once only. Unlike citric acid types as above, you
can make up large quantities and store it without problems even without sulphites.
Target pH is 6.9 - 7.

F008    Buffered Alkaline Fixer

Use undiluted. Target pH is 7.6 and the addition of ammonium chloride gives a fast fixing time.
Delta 100 clears in about 1 minute. Unlike acid fixers, this formulation lasts at least 2 years with no degradation.

S009    A Simple Stop Bath

This is a one shot stop bath with a pH of about 5. The only disadvantage is a slight smell of
sulphur dioxide. When prepared in bulk and stored for a long time, there is no possibility
of growths in the solution