The information on this page is copyright of the author you may reproduce as you wish provided the source is acknowledged.  This article was written several years ago and since them I have sold my film cameras and moved to digital image capture and manipulation. 

Successful E6 Processing - My own Practice

Alan Cartwright PhD

After I retired I found myself with more time and less money to practice photography. I wanted to be able to experiment and  wanted to achieve the sort of turn round  that would be possible using a black and white darkroom – however my interest is in colour slides which I wished to scan and print digitally. So turning to E6 processing seemed to be an obvious route.

However, I could not  find any detailed information about the practicalities of doing E6 processing. Standard text books give lists of temperatures and processing times and one unhelpful handbook simply says its based on experience of black and white processing.  In fact there are a number of issues which make it, in practice, if not in principle quite different. These are temperature control and timing – which includes the numerous different processes. The key to temperature control was for me a Nova film processor, the key to timing was the Photo Timer computer programme which I wrote and is also described on this site. In this article I want to describe how I overcame these problems to the point where I can now reliably process E6 films.

I was not completely alone, I spoke to Mark at Exeter Cameras who advised me about using the chemicals which they supply. I also spoke to several people at Nova Darkroom who were also helpful. However, in spite of their kindness, my naiveté was such that I did not have a mental template to absorb the information that I was given. I had to go away and experiment - though I must say that from the outset I achieved a degree of success which was encouraging. I am writing to provide others with such a template by describing the procedures I use and why. Some of what I say may seem obvious - but at the beginning it was not so too me - so its included here. I don’t claim to be an expert; I am only describing what has worked for me.

I have divided the piece into two parts. The first describes my approach to the basic process, setting, temperature, agitation, washing, timing. The second describes application of these principles in processing a film.

The Basic Process

The chemicals I use are produced by Costel which I obtain from Exeter cameras. There are four chemicals developer, reversal bath, colour developer and fix. With washes required between developer and reversal bath, colour developer and fix and after fix. I am currently mixing 600 ml at a time. I use these in two batches of 300 ml – developing 3 films in each batch. Each time the chemicals are used the first developer time is increased by 10% to account for exhaustion of the developer. As changes in temperature and timing effect the outcome I aim for absolute consistency in my procedures.

The complete process takes about 38 minutes – the actual time being determined by the age of the chemicals and whether the film is to be pushed or pulled. These factors only effect the first developer time. There are eight procedures involved. During the three of the main chemical procedures (first developer, colour developer and fix) ,  washes need to be prepared and the film systematically agitated. Though this sounds intimidating – and it certainly effected me that way – by systematisation using my photo timer software I have reduced this to a reliable routine.

The Setting:

After I retired we moved from the country into a town where I am fortunate in having a bedroom which I use as a study - this has a small enclosed, well ventilated, en-suite which one day is to be converted into a shower room,  which I use for processing. At first I thought I would have to make it light tight. That was not necessary as the only point where complete darkness is required is when loading the film into the developing tank – which can be done easily using a film changing bag. I use a bottle opener to take the top from the film. When needed I bring power into the room via an extension lead with a power breaker as a safety feature.

Temperature:

Temperature is critical in E6 processing. Basically the chemicals need to be kept as close to 38 degrees centigrade as possible. Temperature variations lead to unpredictable results. I finally came to the conclusion that the only way to achieve this was to purchase a film processor – which I obtained in a sale from Nova Darkroom. Why its called a film processor (which for me implies mechanical action) I don’t know because it is a temperature controlled bath in which you stand your chemicals and developing tank, keeping them at a constant temperature. I am fairly sure that this could be done DIY.

In order to get a constant temperature throughout the liquids, and to maintain a basic temperature mass, you need to have a reasonable amount of water in the processor. The first problem I had was that the containers supplied were not really designed for working with small quantities of chemicals ( you only need 300 ml for a single film) and everything would float and fall over. I eventually wedged the base plate on which the chemicals stand so that it did not float. I also bought four picnic drinking beakers – these take 330 ml of liquid have screw tops and are different colours. Each is always filled with the same chemical to reduce the likelihood of confusion. The four containers – containing the four chemicals will also fit into the processor with the developing tank. With these I can fill the processor to 75% of its capacity and achieve a stable temperature in the chemicals.

With my chemicals prepared I scoop out a quantity of water from the processor (I tend not to empty it after use) and replace this with warm water. I put the developing tank full of warm water and the chemicals in the processor. I then turn the processor on and cover with foil and black material to keep the heat in. The temperature reaches the desired 40 degrees in an hour or so.

I aim for a temperature of 40 degrees to allow for a two degree drop while pouring and processing. I found starting at 38 degrees would lead to underdevelopment.

Washing

There are lots of different ways that washing films between processes can be done. The procedure I have adopted is to keep 2 two litre plastic bottles (well cleaned as the originally contained milk). During the proceeding process (e.g. while the film is in the developer) I fill each of these with water from the taps getting a balance of about 43 degrees. Although the tolerance for the water temperature is theoretically quite large, in fact, if the wash temperature is low then the tank and the film cool down and the next process is likely to be below temperature. Having poured out the previous chemical I take the tank to the sink and fill with the heated water. I swirl this about and pour out immediately. This is to stop the last process. I then repeat the process more slowly – over the two minute washing period but using all four litres of water.

Agitation

As soon as I have poured a chemical into the development tank, I return the tank to the processor and agitate for 15 seconds using the twiddle stick. I then agitate for the first 15 seconds of every minute the chemical is in the process (except for the reversal bath which should not be agitated). I don’t not take the tank from the processor or rotate the tank as this could effect temperature.

Timing

Timing is critical and I use the photo timer software to direct this. The timings required are determined by the type of chemicals, so I wont discuss them here.

Setting Up the Timer

Further details about the timer are described on the photo timer page from where you can download the document which describes the timer in detail. This is actually a printable version of the timer help files.  I run the timer on my portable computer by on batteries but I could easily run it on my desktop which is in the next room. The timer can be programmed to give verbal messages which are recorded by the user. The importance of using verbal messages is that you don’t have to see the clock – though its psychologically comfortable to do so.

The screen shot below shows the timer set up to process an E6 film rated at 100 ASA, using the chemicals for the second time. The timings are set by the chemical manufacturers. I set a period of 5 seconds for hesitation. That is the timer pauses for five seconds before moving from one process ( contained within a timing event) to another.

These processes can be followed using an ordinary timer but not so easily.

Pre-soak

Whilst warming up the processor the developing tank,filled with clean water, is standing in processor water. When I take the tank out to load the film I pour the water into flask and place this in the processor. This water is used in the pre-soak. With the film loaded I pour the water from the flask into the tank and place this in the processor. Then I start the timer.

I have set time "warnings" on the timer for the pre soak so I get a verbal message after 30 seconds telling me how long to go and will get others at 20, 15, 10 and 5 seconds. Finally, I have set a ‘stop message’ for pre-soak which tells me that it is time start the first developer. Then I get a message saying "paused" and five seconds later "First Developer".

When I get the stop message I take the tank to the sink pour out the water. This is often coloured with dye which is quite normal. I Remove the first developer from the processor and pour it into the tank. I return the tank to the processor as the ‘first developer’ message starts and start agitation. The tank remains in the processor until it is time to remove the chemical.

These stages involve similar processes but obviously differ in time and content. In each case the process starts with a 15 second agitation period. A special message has been set – ‘stop agitation’ which indicates that the agitation period is now over. At this point I move to the sink and start mixing the wash water. A warning message will occur on the next minute telling me how long this process has to go. Because agitation is required every minute an alarm will go off (a bell) to tell me to start agitating, 15 seconds later a buzzer tells me to stop. I then return to mixing the wash. At the end of the process I get a message telling me to start the wash. I pour the chemicals into their containers and move to the sink where I wash the film.

Final Wash.

For the final wash I complete the wash procedure described above and then force wash for 5 minutes. This is done using an old hand shower connection from the tap which is placed into the tank and runs cold water through the film. Finally, I put a single wash into the tank using Jessop's Econowet. I hang the film above the toilet – its too long to hang above the sink-  and leave to dry. I do not attempt to sponge the film as on one occasion I damaged the emulsion. Its not required when using the Econowet.

Conclusion

It took about 20 films to work out my procedures and to become confident in what I was doing.  It was fairly stressful as I often did not know where the problems were but now I am quite relaxed about the whole procedure.  Much of the stress came from the incomplete and sometimes inconsistent information that I gleaned from reading.   

When I first started the stop messages sent by the timer were very important - they stopped me getting confused at a stage where I was not really conversant with the processes.  I did not have to read anything or even watch a clock. The messages simply told me what to do next. Now they are less necessary and I often use time warnings alone.

My procedure preparing the washes during the chemical processes might sound somewhat pressurised but it has two advantages. Firstly, the temperature of the wash is controlled. Secondly, I am concentrating on the process so my attention does not wander (which it does easily) and I am less likely to make mistakes.

One problem I found difficult was a lack of information about the effects of not following the procedures properly. The information I found was mainly to do with the effects of one process being contaminated by another. Provided you are rigorous these should not be a problem. The main problems I experienced were under development -–that is the processed film was too dark. There seem to be two main causes of this. Firstly, the timing is too short. I have found that it is important to follow the instructions on the chemicals rather than any other source when determining timing. The second cause seems to be low temperature which is why I have striven to create a method which can be applied consistently as if I was a machine.

Learning to process E6 film has transformed my photography. I no longer feel the same pressure over the costs of processing and I don’t have to wait up to 10 days (which is how long some of the cheaper high street labs can take) to get my films back.