Paper reversal

[George Papantoniou]

Has anyone tried B&W paper reversal process ? I gave it a try a few years ago and had partial sucess (Rc paper was OK, FB didn't make it, had marks and fogging problems). I used first and second dev with Neutol, permanganate bleach and fogging with white light. Had real trouble washing the bleach off the FB paper before fogging, and that's what might have caused the problems. Tried real hard to do it though...
If anyone has had sucess on FB paper, could he tell me how he did it? I'd like to try it once again and would need some help to get it right this time...

 

[DimDim]

Did you used a clearing bath?
When I do films that way, I use 50 grams of Natrium sulfite in a liter water after the bleach.

 

[Bob Carnie]

George,
Are you talking about solorization??
If so getting rid of the hydroquinonne in the developer would be the first thing I would do.
google William L. Jolly Berkeley

His manuscript on solarization is the best I have ever seen ,and it is written so well even a dummie like myself understood , some of what he laid out.

 

[Donald Qualls]

You might try a different bleach than permanganate with the fiber papers. It seems to me permangate is well known for staining organic fibers, which would seem to make it a poor choice for bleaching a fiber based print. I've seen a formula for a copper sulfate based reversal bleach (copper sulfate and sulfuric acid, similar overall to the permangante bleaches used for reversal) that was originally for reversing infrared film; this material shouldn't stain organic fibers as badly as permanganate, and isn't much if any more toxic (nor is it, like dichromate bleach, carcinogenic, AFAIK). Of the three common acidic reversal bleaches, I'd expect the copper sulfate bleach to work best on fiber paper.

Ferricyanide bleaches like Farmer's Reducer, unfortunately, rely on either rehalogenating the silver (which would give a solid black after light fogging) or rehalogenating and then fixing away the reduced silver (which would also fix away the undeveloped halide needed to produce the reversal image).

 

[DimDim]

I've seen a formula for a copper sulfate based reversal bleach

Can you give me more details?
I always use dichromate. I tried permanganate only once, perhaps with too much acid but the filmstrip could best be described as a burned painting with cracks in the emulsion like in dried mud.

 

[psvensson]

Has anyone tried reversal printing with a dye toner like the Berg Color Tone System? I figure it should work, but I'm not sure of the d-max achievable. The Berg kit says it can produce colored slides from b&w film

I imagine the process would be something like this:
1. B&W developer
2. Dye bath - dye adheres to undeveloped halide
3. bleach-fix, clears out all silver, leaving dye

A problem with the Berg Kit would be that it doesn't provide any neutral black dye, just colors, but maybe an acceptable tone of low saturation can be created by mixing dyes.

 

[rjr]

"I imagine the process would be something like this:
1. B&W developer
2. Dye bath - dye adheres to undeveloped halide
3. bleach-fix, clears out all silver, leaving dye"

I tried this with a thiorea toner and blix taken from a commercial E6 kit - my blix was quite exhausted, but it worked.

Later this year I plan on pursueing that path... as you may imagine, I ended up with brownish toned prints...

 

[George Papantoniou]

Well, thank you all for the replies, and:

Dim Dim, yes I use a clearing bath and it is Natrium Sulphite. The whole process is based on the standard film reversal thing. The problem is that I read that the permanganate should be really well removed (washed) before putting the paper in the clearing bath...

Bob, no, I'm not doing it by overexposing the paper...

Donald, I'll try to find the Copper bleach formula. Could it be in the Darkroom Cookbook ?

Dim Dim, I can try Dichromate (not afraid of cancer and see how it goes...

Psvennson, where can the Berg Kit be found ??

Rjr, are you using the theiourea toner after the developer, instead of the dye ? If so, how will it adhere to the undeveloped silver halides and not to the developed silver ?

 

[Donald Qualls]

Copper Sulfate (and other) bleach formulae

You would want to leave the sodium chloride out of the copper sulfate bleach formula shown on this page to avoid rehalogenating the silver developed in the first developer step; instead, you want the silver to simply convert to sulfate and dissolve (as it will do in the absence of a halide that would reprecipitate it). Once this is completed, and the bleach cleared from the paper (sodium sulfite bath, HCA should work, or a plain water wash) you can fog and redevelop as usual.

Once reversed, you could also use the formulae on this page to control image tone, of course...

 

[Bob Carnie]

If anyone could post an image showing what this process looks like or direct me to a web page I would be grateful

 

[psvensson]

George, the Berg kit is found in U.S. stores. If you're in Europe, the Fotospeed Palette toner may be easier to find. I think the principle is the same. But rjr's tip about thiourea toner sounds better. I think I may try this if I can get my hands on some reasonably priced Panalure so I can print from slides.

 

[fhovie]

I just got done doing some Mordancage prints - It is a partial reversing process - it only reverses the areas of greatest densities. The solution uses copper chloride, acetic acid and h2o2 20%vol. The solution bleaches and lifts areas of the emulsion off and then you redevelop. It is really a neat effect. I posted some of mine in my gallery - and unblinking eye has a very good artical on the process.

 

[George Papantoniou]

Hi all,
Thanks again for the replies,
psvensson I understand now that you're talking about a chromogenic toner kit. OK, but normally, I think, those kits just convert the developed silver to dyes and so, when using on a processed print it should come out in colour but not reversed (I've never used one, so I might be wrong...) if now used on a print that is developed but not yet fixed, I can't imagine how it would affect the undeveloped silver halides and not the developed silver...
Donald, thank you for the tip, I'll look for it...
Now I'm off for a weekend of trekking (with my trusty Rolleiflex in the backpack), talk to you all on Monday
Cheers

 

[psvensson]

George, actually it appears the dye toners work like other two-bath toners - they convert silver halides, not silver. If you're working from a finished print you have to bleach first, then dye.

 

[George Papantoniou]

psvensson, how stupid of me, you're absolutely right. So, that's why the thiocarbamide toner (and maybe other ones that affect the halides and not the silver) should also work.
I have to give it a try now to see how it goes. I should try the other solution too, using copper bleach instead of permanganate...
Thanks again

George

 

[psvensson]

I tried thiocarbamide reversal this weekend, and it seemed to work, but the results weren't very compelling. D-min is high - the paper turns cream - and D-min is low. Perhaps a more aggressive bleach would clear out the D-min, but that would probably affect D-max as well. I'm probably looking for another toner.

Here's what I did:
1. Developed in Neutol WA.
2. Immersed in 1l water with 2g thiocarbamide + 50 g carbonate.
3. Cleared in Paterson Universal Bleach-Fix. (Also tried bleach bath from Kodak Sepia II, followed by fix)

The paper was Ilford MGIV

 

[George Papantoniou]

Maybe the thiocarbamide wasn't strong enough to affect all the undeveloped silver halides... I guess too that since the parts of the print that are developed (the ones exposed to light under the enlarger) will never be completely turned to metallic silver by the developer (there will always be some silver halides left) the reversed print will never have really white highlights... I had the same problem when I did the classic reversal process with sucess on RC papers... But I don't mind this problem much, I can live with it... I guess that if you used a stronger developer (Dektol instead of Neutol WA) and you developed for 3-4 minutes you might have had better highlights...
I hope that' I'll find the time during the weekend to try the trick myself.
Cheers,

George

 

[psvensson]

George, I think your analysis is right. I may try stronger developer next time.

In listing the process above, I forgot to mention that I washed in water between each step.