Modify C41 RA chems for E6?

athbr · Jun 22, 2019

(Purely academic question as I’ve yet to take the plunge for C41 home dev let alone slides. But I always enjoy the wisdom I receive here.)

Could C41 RA chemicals be adapted for E6 use? Note, I don’t mean using stock C41 plus a BW FD to achieve reversal as has been demonstrated with some success here before.

I mean making the necessary adaptations to the chemicals to get better approximations of E6 process.

For example, I know E6 bleach and fix are stronger (more FeNa EDTA and Amm hypo, respectively). Perhaps a less diluted working solution plus whatever else needed mixed in could do the trick?

As for the Developer, could you mix parts A and B (part C being the one containing CD4), and scratch mix a CD3 (and whatever else) based part C?

I guess I’m SOL for the FD and Stab but I already have (I think) most of the stuff for scratch mixing FD and I think I can score the formalin for the stab easily enough.

Couldn’t find anything like this via search. Has it been done before?

mshchem · Jun 22, 2019

No No No.
We will all organize E6 smuggling operations.

Anon Ymous · Jun 22, 2019

C41 fixer can be used as is, there's probably not much of a difference, if any.

C41 bleach is nowadays PDTA based, which is stronger than EDTA. Both processes started with an EDTA bleach, but the C41 one evolved and that's the reason for the short bleaching times, otherwise you'd still need to bleach for longer than 6'. Theoretically, E6 isn't rated for such bleaches, but so far nobody has mentioned any failures about faded dyes, at least after few years. Actually, people have also been using ferricyanide bleaches effectively, which are even worse... Regardless of that, keep in mind that in E6 all of the silver needs to be bleached back, so bleaching times may need to be extended.

Now, E6 CD is very different from C41. It's not just that one uses CD3 and the other CD4. There's a huge pH difference (12 vs 10), which requires trisodium phosphate plus sodium hydroxide to get that high, but also a small amount of citrazinic acid. To cut a long story short, forget about modifying C41 developer.

athbr · Jun 22, 2019

mshchem said:
No No No.
We will all organize E6 smuggling operations.

Oh I wish

athbr · Jun 22, 2019

Anon Ymous said:
C41 fixer can be used as is, there's probably not much of a difference, if any.

C41 bleach is nowadays PDTA based, which is stronger than EDTA. Both processes started with an EDTA bleach, but the C41 one evolved and that's the reason for the short bleaching times, otherwise you'd still need to bleach for longer than 6'. Theoretically, E6 isn't rated for such bleaches, but so far nobody has mentioned any failures about faded dyes, at least after few years. Actually, people have also been using ferricyanide bleaches effectively, which are even worse... Regardless of that, keep in mind that in E6 all of the silver needs to be bleached back, so bleaching times may need to be extended.

Now, E6 CD is very different from C41. It's not just that one uses CD3 and the other CD4. There's a huge pH difference (12 vs 10), which requires trisodium phosphate plus sodium hydroxide to get that high, but also a small amount of citrazinic acid. To cut a long story short, forget about modifying C41 developer.

I seem to have all that available locally. Would it not be possible to add it in?

Photo Engineer · Jun 22, 2019

E6 CD contains ethylene diamine and a soluble competing coupler along with several other ingredients that improve dye formation and image quality. Using C41 to get good results with E6 film is probably quite difficult but you can probably get some sort of usable image. In any event, you are really on your own.

PE

athbr · Jun 22, 2019

PE,

Just to clarify the question is if some of the C41 CD (parts A and/or B) could be cannibalized to make E6 CD to avoid full on scratch mixing.

Id have imagined that considering how decent the results are for E6 in C41 (not xpro) at least visually — there was a thread updated recently that seemed promising — that a modified CD that uses CD3 (among the aforementioned) would be even closer.

mshchem · Jun 22, 2019

I used E1 chemistry to process modern Provia Fujichrome. You will get images but you won't get great images. The real question is why shoot reversal film, unless like me, you project slides.
Reversal film is fun to process, to get acceptable images I bracket every shot so a 36 exposure roll is a 12 exposure roll.

I still think smuggling is your best bet

Photo Engineer · Jun 22, 2019

athbr said:
PE,

Just to clarify the question is if some of the C41 CD (parts A and/or B) could be cannibalized to make E6 CD to avoid full on scratch mixing.

Id have imagined that considering how decent the results are for E6 in C41 (not xpro) at least visually — there was a thread updated recently that seemed promising — that a modified CD that uses CD3 (among the aforementioned) would be even closer.

E6 in C41 is doable with high contrast and crossover, but it works because negative processing is very simple compared to reversal. In reversal, you need a high capacity bleach and fix due to the Silver and Silver Halide load. You need Formalin and you need a reversal chemical or a reversal step. As I said, it will work to give images, but they will be low quality and basically you are on your own.

E6 films in C41 as negatives can give some pretty startling images with high quality, but reversal is another matter.

PE

Anon Ymous · Jun 22, 2019

athbr said:
I seem to have all that available locally. Would it not be possible to add it in?

If you exclude what you think about adding to existing solutions, then there's not much left. Certainly nothing particularly hard to find, or exotic. If you do have, or can source the most critical ingredients for E6 CD, then I'd suggest mixing your own. Stefan Lange's formulae produce excellent results that I have personally used and can confirm that work very well. Have a look at the link below for the E6 CD formula, the one under "RECEIPT I, base receipt". For an FD formula, I'd suggest the one in post #14. The reason I propose the CD formula from post #1 is that it is simpler.

https://www.photrio.com/forum/threads/e6-homebrew-chromebrew-warnig-longer-than-assumend.32721/

athbr · Jun 22, 2019

mshchem said:
I used E1 chemistry to process modern Provia Fujichrome. You will get images but you won't get great images. The real question is why shoot reversal film, unless like me, you project slides.
Reversal film is fun to process, to get acceptable images I bracket every shot so a 36 exposure roll is a 12 exposure roll.

I still think smuggling is your best bet

TBH no reason other than to have fun. I’m a hobbyist and love trying new things. Sadly fun doesn’t come cheap in my neighborhood. So you cut corners where you can.

But one nice benefit is its very high resolution and easier to scan.

mshchem · Jun 22, 2019

athbr said:
TBH no reason other than to have fun. I’m a hobbyist and love trying new things. Sadly fun doesn’t come cheap in my neighborhood. So you cut corners where you can.

But one nice benefit is its very high resolution and easier to scan.

You and I have a lot in common

mshchem · Jun 22, 2019

I bought another of these today. Last one worked well, considering that the film was designed for E6. This is the "new instructions" development at 75 F not 68 F.Back then the emulsions were so soft 75 F was "tropical". Sneeze on the film and you might blow it off.

Photo Engineer · Jun 22, 2019

That is either E1 or E2, right?

mshchem · Jun 22, 2019

Photo Engineer said:
That is either E1 or E2, right?

E1. I was the lunatic that wasted 5 rolls of Provia F a couple years back with one of the half gallon kits. I got it to work, managed something like ASA 16. Looked like typical really bad commercial E4 processing from the 70's.
Testimony to how well EK packaged chemicals in the metal can, divided powder era. I have cans of D-61a that I think have a 1957 date code that still work. I don't use them.

The cans are a bit like Civil Defense goods found in an old fallout shelter.

Modify C41 RA chems for E6?

Privacy & Transparency

Privacy & Transparency