Manipulating silver iodide image

[Athiril]

Long story short,

I have a film strip with images made of what I assume is only or mostly silver iodide (or other non developable silver salts).

It is an E-6 film, the machine borked, and the film sat in the first dev at processing temp (with no agitation) for an hour or so, I was going to rehal it into a colour neg as there was fine negs on the film, but I had already hit the colour dev by that stage and didn't want to stack a neg on a pos.

Anyway, the results are, quite thin black and white positives, which survived the bleach and fix. There is no dye.

This has happened once before, when T-Max was accidentally run through it (inc bleach and fix), it gave the same results, thin black and white positives.



Assuming it's a silver layer that won't budge with any combination of steps of bleach, colour dev etc (and fix), what can I do to get this to a developable silver salt? I can then rehal it over and over to reasonable density slides.

Eg; such as passing the film through chlorine gas to get it to silver chloride?

Would a ferricyanide/bromide bleach do the trick and displace the iodide, that PDTA based bleach doesn't seem to?

Regards.

 

[Photo Engineer]

Dan;

Have you ever considered that it might have formed Ag2S, Silver Sulfide? This can happen. It becomes a mess as nothing can react with it.

PE

 

[Athiril]

Thanks PE,

That does make sense.


Hmm, what about the trick to remove silver tarnish with aluminium? I could dissolve some alfoil in fixer, and add bicarb?

 

[Photo Engineer]

IDK what it would accomplish. But, let us know.

PE

 

[Prof_Pixel]

Ron,

If there really was any Ag left in the film, it sounds like a case for a cohex amplifier from the old days.

 

[Photo Engineer]

Yeah, that would work. But, AgI and Ag2S both poison the catalysis.

So, IDK what would work.

PE

 

[Athiril]

IDK what it would accomplish. But, let us know.

PE

Electrochemical reduction of Silver Sulphide to Silver, but the Silver Sulphide needs to be in contact with the aluminium (which takes up the sulphide) in an electrolytic solution iirc.

 

[Prof_Pixel]

At this point, you really don't know what the image is made of, do you? Is it Ag based or dye based?

 

[Photo Engineer]

Electrochemical reduction of Silver Sulphide to Silver, but the Silver Sulphide needs to be in contact with the aluminium (which takes up the sulphide) in an electrolytic solution iirc.

I got that, but Fred put it better than I did.

We don't know for sure what the yellow is for sure. Sorry for the misunderstanding.

PE

 

[Prof_Pixel]

The original poster said "Anyway, the results are, quite thin black and white positives, which survived the bleach and fix. There is no dye." And I wondered how he arrived at the conclusion there was no dye.

 

[Photo Engineer]

Yeah, my goof.

Oh well.

PE

 

[Athiril]

I'm currently running a test strip of film.

I cut some unprocessed slide film, put it in a solution of sodium sulphide, until it went dark, washed.

I tried tin chloride in acidic environment, aluminium hydroxide, among others to no avail.

Taping a piece of tinfoil to one end (hoping that it'd be close enough for the attraction, assumed I would have to dissolve it to get sufficient contact), and soaking it in a sodium chloride + sodium bicarb solution, then transferring it to a solution of potassium ferricyanide and potassium bromide.. and this seems to have worked completely on the strip.

So if I tape the foil to an unexposed area on the roll with images, that should transfer through that hopefully. Although I wonder if there'll be areas that'll be surrounded by highlights that it wont be able to transfer through.

Last option would be dilute HCl.

 

[Photo Engineer]

Dan;

IDK. This is way outside the norm and I have no experience. I'm very sorry. But, catalytic development might work using H2O2 in the developer (10 ml of 3% peroxide per liter of CD).

PE

 

[Prof_Pixel]

Ron,

Yeh, H2O2 is a lot easier to get than cohex. It's worth a try.


Edit: See for example http://www.google.com/patents/US4097278

 

[Athiril]

I'll give that a go on the next CD run.

Prof_Pixel:

It spent more than an hour in first dev without agitation, the thiocyanate has enough time to remove any remaining halide. The visual appearance is monochromatic, and not coloured. Looks the same as T-Max that went through E-6 once. Among other things. Ron suggested Silver Sulphide.

Bleaching back didn't work. After treating it with aluminium foil and an electrolytic solution, bleaching back has worked (that also worked on the sulphide treated test strip).

So Ron's right in that it was silver sulphide. We makes me worry the sulphur came from the thiocyanate.

 

[Photo Engineer]

If it was fixed, then the "S" came from Hypo probably.

The E6 developer does not use thiocyanate now AFAIL

PE