What strength ferricyanide for color film bleach?

[Athiril]

Potassium Bromide is to convert the developed silver back to Silver Bromide with the oxidising agent. You can use sodium chloride just as well in this case. Ive used this bleach with regular C-41 developer and E-6 fixer (was cheaper) and it works fine. I did use a stop bath after C-41 followed by sulphite (you can combine the 2 or add metabisulphite), rinse and bleach. I used 1+9 cheap white vinegar one shot as a stop. Blix acts as a stop bath in the regular process. You can re-use or replenish the bleach until it stops working, and just mix up fresh stuff when it does. The point of the sulphite is to remove any (and prevent) oxidised developer so that it wont cause stains with the ferricyanide bleach with any developer carryover. And sulphite after rinsing the bleach out was to fully reduce any left over bleach so that it doesnt stick in the film iirc.

Ive done the same with copper sulphate bleach, while it works very well, it affects the colour balance somewhat while ferricyanide doesnt.

 

[Donald Qualls]

Ive done the same with copper sulphate bleach, while it works very well, it affects the colour balance somewhat while ferricyanide doesnt.

Kodak actually still has ferricyanide based bleach as an alternative to the EDTA or PDTA bleaches in their ECN-2 documentation -- and in general, aside from remjet, ECN-2 films and C-41 films and process are virtually interchangeable (look at all the YouTube videos on processing Visions3 in C-41 chemistry -- which is what you're doing if you use Cinestill color films in Cinestill's recommended manner). There is very little if any color shift in this cross process, at least to my eye.

 

[Athiril]

PE would say the dyes wont be stable. He also told me CD-3 (ECN-2) produces a little higher saturation and slightly different hues and gamut effectively than CD-4 (C-41) when used with the same dye couplers.

 

[Donald Qualls]

Which is why cross processing produces "experimental" results -- E6 is a CD-3 based process, as well, so E-6 film processed as a positive with a first developer and C-41 color dev will produce slightly off colors. Not greatly off, but not quite there.

FWIW, I've abandoned home mixing C-41 chemistry for now -- I bought a set of Flexicolor chems and I'm testing replenishment (processing to minimize oxygenation of the developer, and watching negatives carefully for changes in contrast, color shifts, or crossover as the developer ages).

 

[Athiril]

Flexicolor is very good at self balancing when replenished, I had no issue when I used to do it. I even kept it in glass V8 juice bottles.