Examining the ECN-2 process, I also found that Kodak suggested several different bleaches, and surprisingly one of these is the good old ferricyanide-bromide. So a switch from that to ferric EDTA one may have been dictated by a political reason rather then chemical.
Ron did mention one of the potential drawbacks of strong bleaches, strong meaning: stronger than the specified bleach. There may be stabilizing agents embedded in film to protect the dyes from fading. One protection vector may aim at aerial Oxygen and may well be a reducer. Such a reducer may survive treatment in Ferric EDTA but not in Ferricyanide. Since cine film is stored under different conditions (at least in its original target market: professional movie studios) than typical film used in still photography, therefore different stabilizers may be in there.
ECN-2 is specified&tested for very powerful bleaches, e.g. Persulfate is an extremely powerful oxidizer, but this most likely does not translate to C-41 film. As far is immediate image results are concerned, Stefan Lange did extensive tests with C-41 and E-6 and was quite happy with Ferricyanide bleach.
As far as I know a stop bath is mandatory before ferricianyde bleach (any trace of active CD produces stains) and reccomended with modern color bleaches if they are going to be reused to preserve acidic pH.
process ECN-2 page 7-4: Step 4. Stop, Function: stops the development and washes CD-3 from the film; Step 5. Wash, Function: removes excess acid stop. So, there is a stop and a wash.
Hello,
My question related to E-6 processing.
Since I can't find a source of EDTA based bleach, and the available kits are expensive, I started thinking about converting blix to bleach. I can get EnviroPrint Bleach-Fix Replenisher 70 AC or EnviroPrint Bleach-Fix Replenisher 215 AC minilab chemistry. This is a RA-4 blix in two parts, with part B having Ferric ammonium EDTA.
Can I use them for E-6?
Hello,
My question related to E-6 processing.
Since I can't find a source of EDTA based bleach, and the available kits are expensive, I started thinking about converting blix to bleach. I can get EnviroPrint Bleach-Fix Replenisher 70 AC or EnviroPrint Bleach-Fix Replenisher 215 AC minilab chemistry. This is a RA-4 blix in two parts, with part B having Ferric ammonium EDTA.
Can I use them for E-6?
These should - converted to a bleach - definitely work as a basis for E-6. You have to find out the true concentration of these concentrates, but once that's settled you should be good to go.