Borne out of an act of desperation, we had to turn to developing our own E6 large format film. It had become too risky to leave it up to couriers to safely transport our film to the US for processing. A switch to digital looked likely when we realised that many E6 colour chemistry kits are considered 'hazardous', and thus airborne couriers would not transport them. That would have been a heavy blow for us, as there is no present digital alternative that can out-resolve 8x10 large format film. The best digital alternative available would constitute a $50,000.USD investment which includes a medium format camera and matching 39MP back. We didn't fancy the idea of walking around Trinidad with $50,000 worth of camera gear. Digital cameras take the fun out of photography for us, so, things were looking rather bleak for while: we had seriously considered 'closing up shop' with respect to Trinidad Dreamscape. Luckily for us, and for those of you in a similar position, there are E6 chemicals available which will allow slide development which will rival the results from any contemporary professional lab.
We will not be presenting a step-by-step guide here as we did for black and white film processing. The reason for this is that there are quite a few good guides to colour film processing online, so there is no need for us to re-invent the wheel. Additionally, unlike black and white film processing, colour film chemical kits come with very explicit instructions about the developing procedure. The best advice that we can give is to follow these instructions to the letter. In colour film processing, developing stage times are fixed, and temperature control is absolutely critical for the first developing stage, and slightly less so for other stages. There are 2 types of kits available: 3 bath, and 6 bath kits. The argument for 6 bath kits is that the fixer and bleach stages are not combined as in the 3 bath kit, theoretically allowing for a more stable slide that resists fading and colour shifts. We use Tetenal's excellent 3 bath kit. We know of other photographers who have had long-term success with this kit, and we trust their judgement. It is also possible to mix your own chemicals from a stock supply but many of these chemicals have been deemed hazardous for air transport so availability will be a problem.
The first important point to make note of when mixing the chemicals is that under no circumstances should the first developer be contaminated. Even fumes from the colour developer can contaminate the first developer. The first developer should therefore be mixed first and then sealed in its container. Also, the colour developer must be mixed exactly to specification (preferably with a pipette or syringe) or colour shifts will occur. The other main problem that people encounter is maintaining a constant temperature.
The first developer stage of 6 - 7 minutes (depending on the processing method, be it tray or drum) must be held within 1℃ of the recommended temperature. The first developing stage is responsible for the overall slide exposure, and shifts in the temperature may cause an over- or under-exposed slide. The way we maintain the temperature is to establish a waterbath in a 'Rubbermaid' cooler. We pour in a mixture of hot and cold water until a temperature of about 50℃ is attained. We then place the chemical bottles into the bath, and close the lid. We've found that the temperature equilibrates to 40℃ after about 1 hour. While this is happening we pre-heat our processing drum (already containing the film) by allowing hot water to flow over it continuously for 15-20 minutes before we expect to develop. We pour the developer into the drum when the developer temperature has reached 40℃. This is 2℃ above the recommended developing temperature. We have found that there is a temperature drop of 1.5℃ even with the drum preheated. The resultant temperature gives a good average to 38℃ or thereabouts for successful developing of the first stage. The other stages do not require such stringent temperature requirements: maybe to within 3℃. The total developing time goes to about 35-40 minutes per batch. Wash times between the developing stages have no time limits; it's just important to wash the slide with copious amounts of water (the water temperature should be close to the developer temperature) to get rid of the chemicals from the previous stage.
When the slides emerge, they will have a slightly milky appearance. This is normal, so don't panic. Let the slides dry in a dust-free environment overnight.
All images and text © Copyright protected Dr. Rory Roopnarine / Jo-Ann Sookar 1990 - 2017. All rights reserved.