FURTHER PROCESSING TRIALS
By Bill Reid. (Area 20)
As I mentioned in the July N/L. I had been planning to try the `modified formula that our Secretary, Ron Croad, had worked out to try and correct the `tobacco` effect that has troubled me for so long. Ron made a visit and checked through my Weighing & Mixing and processing procedures and found nothing amiss. I also changed every chemical so that only completely `fresh` ones were used, and checked my camera, changing bag, re-loading tank and camera for possible light leakages, but still the problem ocurred.
It came down to the point where we were suspecting the actual C.R.C. E6 Formulae, although people such as Rita & Major Pearle, Tony Chuter, Ron Knowles & Ron Croad were getting consistently perfect results. However a few others apart from myself were continuing to find faults.
What Ron concluded, was, the possibility that, perhaps, Lawrence Edwards, while `tweeking` the chemicals for `minimum` weights & measures, for a `full` Litre sized brew, may have `tweeked` them so finely, that it left a fine line when W&M smaller sizes, such as 600 & 300ml
The chemical which Ron suspected was the amount of CD-3 in the Colour Developer, and some in the Reversal Bath. He did a number of trials, which I am sure you will appreciate, involved a lot of time and work, finally came up with a `brew` that gave results every bit as good as with the One Litre brew, keeping colours and contrast to satisfaction. I saw a good number of these excellent slides and was keen to give this formula a go, but due to my work commitments it took me until July before finally getting enough film exposed and to get around to making up a 600ml brew. The main difference is in some small changes in the weights & measures in the Colour Developer, and the Reversal bath. The other change from previous brews was in using the concentrated `liquid` Bleach, from Albert Raymond. It was a treat to make mix after the powdered EDTA bleach. There was no `sludge` to worry about. In fact I didn`t even `aerate the bleach with an air-pump, as I normally do, and bleaching was to finality over the six films (processed two at a time).
I kept all processing times strictly to Ron`s timings, with only only a slight change in the `WASHING` stages. I have always maintained that the `very` short washes given for workers using small home processing tanks, don`t work as well as those given for more `professional` equipment. It takes `four` fills of clean water before the colour of the `chemical` clears from the water, therefore, I give four 30 second swills of the tank before I set the timer for the actual time and give each further fill a full minute before changing, and feel very satisfied that the film(s) are getting a good wash before the next bath is poured in.
For the short `Rinses` I do exactly as per instructions, as some of the Reversal and/or Conditioner `must` remain in the film emulsion for the Colour Developer and Bleach to do their work fully. I haven`t found any problems giving the film(s) the full washing between Bleach & Fixer. instead of the short rinse as stated. The short rinse certainly works, but I just don`t like seeing the Fixer turn to the same colour as the bleach!
Well! How did things go? For some reason the first films had a very prominent `green` shadow! This, I wasn`t expecting! Whatever problems the tobacco effect had been giving, the CRC formula seemed to have got rid of any `green` problems. However, for the second films, I increased my thermostat by half-a-degree and gave 15 seconds extra in the First Developer which corrected the colour balance, but sadly the `green` returned for the third films, although not anything as extreme as in the first ones!! In spite of the obvious `degriation` in the first films, the other four films were perfectly acceptable, with a good few being very good indeed, and I was satisfied simply not getting any of that `tobacco` effect.
I am putting the `green` shadows down to not having W&M`d or processed for virtually a whole year, and that I may have slipped up somewhere along the way. Therefore a second W&M and processing would be preferred before making any conclusive comments. But, again, lack of time is the restraining factor and at this moment I haven`t had time for further W&M sessions.
Meanwhile, I received a letter from an Area One member, David Boyce, via Co-ordinator, Alan Frame, which gives his feelings on the `tobacco` effect.... "I find the Newsletter very interesting, and would like to take this opportunity to make one or two comments: Brown (tobacco) cast with 3M film; There has been some discussion of this in the Newsletter. About 4 or 5 years ago I bought two rolls of 3M. The film was process paid and phenomenally cheap. The results exhibited a warm reddish cast which seems akin to the tobacco cast described in the Newsletter. It would appear then to be a trait of the film rather than the processing.
Water supply: If it were discovered that a type of bottled water (such as Halford`s battery top-up water) available nationally, was always from the same source no matter when and where purchased, would use this instead of tap water which is not a good way of eliminating a substantial variable and standardising results? members in one area could compare results with those in other places knowing that variation in water supply was not a factor.
Comparison of kits: Why do the photo magazines not do a comparison test of the various E6 Kits available and asses the results? It seems obvious that Jessop, Paterson and Photo Technology are identical chemistries, identically sourced (and incidentally the Jessop one is good value) but other kits are different, like the Barfen 4 bath and of course the C.R.C. Kit, and I think it would be interesting to see a comparison. What about the Club donating a kit to one of the Photo Mags and suggesting such a test, including also one film to be sent to a professional E6 lab, and all results to be compared? Thanks for listening to my thoughts - but, I hope, not entirely irrelevant!".
David`s comments are certainly interesting. `SADLY` the C.R.C. Kit is now no-more, having been taken off the market due to work commitments by Kevin Craske, who produced them, so this stops a comparison test being possible. However if you read back through past Newsletters you will find most kits have had comments made about them from various members. The `tobacco` effect that has troubled me did in fact, occur with both 3M & Konicachrome film, so would suggest that it wasn`t just due to `one` make of film.
Ron Knowles has sent me some sample slides from these modifications and has produced some cracking slides.
The `modified formula follows on the next two pages. Note the changes in many chemical weights & measures, the Ph values and Shelf life statements, and that the formulae is as modified by Ron Croad as in October 1991.