E-6 reversing developer in B&W reversal?

Donald Qualls · Jun 22, 2020

Some (most?) E-6 kits use a fogging developer to avoid the need for a separate reversal bath or light exposure for reversal.

Almost all black and white reversal processes use light exposure reversal (unless they use a thiourea sepia toner or similar to directly develop and tone the undeveloped halide).

Is there a sensible reason (other than cost, and we wouldn't be doing some of the things we do if cost-effectiveness were everything, would we?) not to use the reversing color developer from an E-6 kit as the second developer in a black and white reversal? That way the entire process could be done without opening the tank.

dE fENDER · Jun 22, 2020

Color developer from standard E-6 will not be able to develop required density on b+w material, unless you get a black color coupler and add it to the solution.

Of course, you can do the whole process without opening, just use any chemical reversal bath, FOMA for example:
https://www.foma.cz/en/fomapan-R-100

You can try to combine b+w developer and reversal bath, but you receive some stability problems. For example, if you will try to use tin chloride, you will also receive unstable tin toning, which is not always desirable
http://www.pnp.by/tin-toning-process/

Donald Qualls · Jun 22, 2020

dE fENDER said:
Color developer from standard E-6 will not be able to develop required density on b+w material, unless you get a black color coupler and add it to the solution.

Okay, that's a sensible reason. Add black color couplers, though, and your developer would be usable *only* for B&W reversal (being a fogging developer to start with).

glbeas · Jun 22, 2020

Any reason the tin chloride couldnt be used as a separate intermediate step? Or does it need to work in conjunction with a developer?

grainyvision · Jun 22, 2020

If you're using a reversal process that removes all of the developed silver but leaves behind undeveloped silver, you might look into using sodium dithionite, sold commercial as "iron out" powder. Mix that and a bit of carbonate for alkalinity and you'll have an extremely active (but unstable!) fogging developer. It is practically impossible to keep in any kind of solvent for more than a day at a time though. It's very soluble so I recommend mixing it just before using it, probably 4g of iron out and 4g of carbonate to 1L of water should work fine. It's an extremely strong agent.

note! Do not add any strong acid (even as strong as oxalic or citric) to iron out powder. I believe dithionite itself is stable in acid without repercussions, but whatever contaminates go along with iron out turn into hydrogen sulfide (rotten egg smell, very toxic, very flammable) when put into a strong acid. At neutral pH (ie, with just water) it is only a weak developer and primarily a fogging agent but will act much slower at both

Raghu Kuvempunagar · Jun 23, 2020

dE fENDER said:
unless you get a black color coupler and add it to the solution.

Donald Qualls said:
Okay, that's a sensible reason. Add black color couplers

What are these black couplers chemically? Can they be used with more easily available C41 developer?

halfaman · Jun 23, 2020

This question is analogue to use C-41 developer for B/W film. C-41 developer is designed to produce the negative image with dyes, not with silver. I think PE claimed somewhere that the silver density produced with C-41 is very low. Same thing would be applied to E-6 CD.

Donald Qualls · Jun 23, 2020

I've seen C-41 developer recommended for low contrast B&W development -- for instance, to get pictorial contrast from (naturally high contrast) document films like Copex Rapid.

I had though E-6 color developer would be somewhat more active in this regard, since slides are often touted as having higher contrast than color negatives -- but again, that's the dye image, not the silver one.

Dye couplers are normally included in the various emulsion layers in C-41 or E=-6, including black dye couplers for B&W C-41 films. They're available in color toning kits, which work by rehalogenating a developed print, then redeveloping with dye couplers added to the developer to produce a dye image, followed by blixing away the silver image -- but I don't know of any of those that use black dye (because, why?!). A dye-based intensifier might be available, but usually one uses silver-based technology for that purpose.

destroya · Jun 23, 2020

I use C41 developer to develop the last of my tech pan. best results i've gotten without the dedicated tech pan developer.

like mentioned above, I use Iron out, which also does the second developer and fixing along with reversal, all in 1 nice easy step.

john

Raghu Kuvempunagar · Jun 23, 2020

destroya said:
I use C41 developer to develop the last of my tech pan. best results i've gotten without the dedicated tech pan developer.

Is there any speed loss?

Would be interesting if it also works well for Adox CMS 20 ii.

Donald Qualls · Jun 23, 2020

Raghu Kuvempunagar said:
Is there any speed loss?

Would be interesting if it also works well for Adox CMS 20 ii.

It wouldn't surprise me -- if it works well with Tech Pan, it should work with almost any document film. I'll have to remember that next time I have a roll of Copex Rapid in my Minolta 16 cameras.

dE fENDER · Jun 23, 2020

Raghu Kuvempunagar said:
What are these black couplers chemically? Can they be used with more easily available C41 developer?

For example, some konica patent disclose resorcinol-type as black coupler:
https://patentimages.storage.googleapis.com/5d/d0/6e/b9f0201d5c6367/EP0568777A1.pdf

It is non-diffusible coupler, but without paraffin group it will become diffusible. Pure resorcinol give some colored image, so I'm afraid it will not be suitable. Usually it will use the mix of 3 types couplers and change proportions on tests result, the simple combination, used for dark paper tones are: acetoacetanilide, phenylmethylpirazolone and 1-naphtol (2 weight equivalent of last one and 1 of first and second as starting point).

destroya · Jun 24, 2020

Raghu Kuvempunagar said:
Is there any speed loss?

Would be interesting if it also works well for Adox CMS 20 ii.

I shoot the tech pan at 32, C41 straight for 7 3/4 min at 70 degrees, so I assume no speed loss.

I have 2 rolls of CMS 20 but no idea where to start with it, so I too would like to see the results. their dedicated developer works well, but is expensive

john

Donald Qualls · Jun 24, 2020

I've processed document films roughly similar to CMS 20 in Parodinal at 1:100 -- I should have a record of the time I used when I'm at home. That may provide a hint for how long to apply C-41 relative to Tech Pan, since I'm certain others have used (Pa)Rodinal 1:100 on Tech Pan over time.

Or you could just do a leader test. I've used 80% of the time for leader to reach DMax in the light for unknown film in the past.

Raghu Kuvempunagar · Jun 24, 2020

As far as I'm concerned, C41 developer would be interesting in the context of Adox CMS 20 ii only if there's no significant speed loss. Otherwise there're cheaper DIY alternatives. I used a reduced pH version of Kalogen for the ortho film sold by Astrum and it gave me good results though with some loss in speed.

138S · Jun 24, 2020

Donald Qualls said:
Almost all black and white reversal processes use light exposure reversal (unless they use a thiourea sepia toner or similar to directly develop and tone the undeveloped halide).

Making a fogging developer it's quite easy, add a (for example) Sn based fogging agent to the BW reversal developer.

Donald Qualls · Jun 24, 2020

138S said:
Making a fogging developer it's quite easy, add a (for example) Sn based fogging agent to the BW reversal developer.

But, as has been noted before (perhaps in other threads) stannous chloride isn't stable in solution. Probably simpler to use the sodium dithionate, which also isn't stable in solution, but is its own developer, not as critical on amount (because it processes to completion), and cheap enough to just one-shot without pain.

138S · Jun 24, 2020

Donald Qualls said:
But, as has been noted before (perhaps in other threads) stannous chloride isn't stable in solution.

I throw the powder in the developer just before usage...

As it is soluble in other liquids, like in ethanol, perhaps it can be had disolved in that way, and dosed with a syringe in the developer just before usage.

Good to have learned that about sodium dithionate, I was not aware.

Anyway presently I'm trying to do the second development not to completion.

Raghu Kuvempunagar · Jun 24, 2020

Donald Qualls said:
Probably simpler to use the sodium dithionate, which also isn't stable in solution, but is its own developer, not as critical on amount (because it processes to completion), and cheap enough to just one-shot without pain.

138S said:
Good to have learned that about sodium dithionate, I was not aware.

It is sodium dithionite (Na2S2O4) and not dithionate (Na2S2O6). Also called sodium hydrosulphite.

138S · Jun 25, 2020

Raghu Kuvempunagar said:
It is sodium dithionite (Na2S2O4) and not dithionate (Na2S2O6). Also called sodium hydrosulphite.

OK, thanks, this is in the Kodak FD-70...

Donald Qualls · Jun 25, 2020

138S said:
OK, thanks, this is in the Kodak FD-70...

Yep, sorry, i spell just fine, but my typing has been corrupted by easy backspace key. Dithionite is also sold as a commercial laundry product, "Iron Out" that's been used directly as a fogging developer. Make an alkaline solution and it goes to town, or so I've read.

138S · Jun 25, 2020

Donald Qualls said:
Yep, sorry, i spell just fine, but my typing has been corrupted by easy backspace key. Dithionite is also sold as a commercial laundry product, "Iron Out" that's been used directly as a fogging developer. Make an alkaline solution and it goes to town, or so I've read.

Yeah...

It will be pure fun to try it, thanks.

Nobody would say that it isn't a Kodak's MSDS

E-6 reversing developer in B&W reversal?

Privacy & Transparency

Privacy & Transparency