Variable Colour Bias E6 First Developers

By Terry Dennet (Area 3+)

In an early club newsletter there appeared a very useful trouble-shooting diagram showing the effects and interactions on a film of the first developer chemicals. This became the starting point for the experiments in this paper.

In an early club newsletter there appeared a very useful trouble-shooting diagram showing the effects and interactions on a film of the first developer chemicals. This became the starting point for the experiments in this paper.

A lot of work had obviously gone into the original diagram so I hope our club librarian can dig into the archives and give due credit to the original author. So far as I can tell this diagram referred to the processing of the clubs first film stock Ferrrania color. Since this only dealt with, the first developer, I felt it probable that these data would also apply to any modern E 6 developer formulae as well. - Broadly speaking that has been the case in my experiments.

The original aim in compounding the Blue formulae given in this paper, was to see if I could produce a blue or cyan base tone on film to replace the rather messy ammonia developed blue Diazo Text slides then used by our Institute scientists.

It became clear in the testing that this would indeed work and it might also be possible to make a developer to improve the color of daylight film shot without a filter in tungsten light. Changing other developer component in accordance with the comments in (fig 1) led to a separate formulae giving a yellow reddish bias. Many others variations are probably possible especially by manipulating the Ph as noted below.

The Film Stock
The initial experiments were done on Kodak Ektachrome 100 but a test with the warm Bias developer on Fijichrome showed better warm results on that film so Kodak film was only used thereafter with the Blue Bias developer

The Developers
The two experimental developers given below show that it is possible to produce what I now call a Variable color Bias First Developer-.to produce either a bluish or yellow-reddish bias in the final slide. As can be seen from the illustrations, the color range is quite different from one obtained using a filter or shooting Tungsten film in day light.
It should be noted that the black and white developer chosen for this work at the time was was the old type Kodak HC110. 

This Developer had a thicker consistency than the latest batches of the product and a darker color. It seems probable that Kodak have made changes to this developer for environmental reasons, so some adjustments are probably needed to my suggested dilutions.

First thoughts on the possible componant structure of the Developer
HC110………………..............................…10cc
Water………………………....................…310ccDilution B old style thick developer*
Possible additives
10% Hypo………………......…..............…silver solvents
0.1% Pot Iodide
10% Pot Brom……………......................…Antifogs color modifiers
0% Sodium Sulphite
10% Borax……………………..............….Plus Ph
10% Pot Metabisulphite………..…..............minus Ph
Ascorbic Acid
Phenidone Solution
Metol Solution………………......................contrast additives
Hydroquinone Solution

Color Balance effects
Sulphite……………........................... reduction = cool balance Increase = warm balance
Pot Brom........................................... Acts as restrainer of red green increase = red increase
Decrease=cyan increase
Pot Iodide…………......................… acts as highlight retrainer and gives more blue
Ph changes………….....................… green increase with plus Ph.magenta.
(See figures 1&2 below).

Basic Blue Bias First Developer
Kodak HC110 Stock dilution (b)..................................................................10cc measure with a pipetteWater.................................................................................................310cc
10% Hypo....................................................................................................13cc
Develop 8 minutes at 38 degrees normal film speed. Ok
Wash and follow with the normal E 6 process color developer and Blix

Basic Yellow Bias First Developer
Kodak HC110 Stock dilution (b) ................................................................10c measure with a pipette
Water..........................................................................................................310cc
10% Hypo...................................................................................................4cc
0.1% Potassium Iodide................................................................................5cc

Develop 8 minutes at 38 degrees film speed was reduced by 50 % so 100 ISO shoot at ISO 50 A test strip test is advised with your first experimental film Wash and then follow with the rest of the E6 process..