B&W Reversal with Hydrogen Peroxide

relistan · Jan 17, 2021

I tried a couple more experiments today that were interesting. Here are some of the things I learned:

The ctric acid/EDTA/zinc sulfate/peroxide bleach that I used yesterday was still working fine today (~24 hours later)
Citric acid bleach works faster and better without the EDTA
You can used EDTA by itself if you add zinc sulfate

The following citric acid bleach works but is slow:

3% hydrogen peroxide — 20ml
citric acid — 0.5g
zinc sulfate — 0.6g
sodium bicarbonate to pH about 4
20 minutes @ 30C

I got pretty even bleaching, no blistering that I could see in a loupe.

The following also works! But is also slow. I have not seen this anywhere, this is something I just mixed up to try:

3% hydrogen peroxide — 20ml
12.8% EDTA solution — 5ml
zinc sulfate — 0.3g
pH about 8
14 minutes @ 30C

This is more or less 1:1 peroxide to EDTA. It reacts very similarly to the acetic acid/peroxide bleach except that, after the initial fast run of bleaching, it still takes a long time to finish. Note the pH! I had tried this before to no avail, but the zinc sulfate being there seems to make it work. I expect that the high pH means that the bleach will not keep well since hydrogen peroxide tends to break down at higher pH. I will see tomorrow if it still works. I may also add some more zinc sulfate. On the flip side, it will be interesting to see if this bleach gets faster overnight. I do not know if EDTA can form peracetic acid or not. And if it can, I do not know if the high pH will prevent it. I think a bleach that works well without peracetic acid will be better for more films.

Both of the above bleaches start out clear, but as they bleach the film they turn a milky color. Over night the citric/edta/peroxide/zinc sulfate bleach deposited a milky layer on the inside of the glass container that was holding it. This is likely either silver citrate or silver sulfate. Or zinc citrate? Or maybe all of those.

relistan · Jan 17, 2021

Hmm, here is another very interesting patent along the lines of what I tried today! https://patentimages.storage.googleapis.com/de/40/f2/5d21197d6d2b67/US4454224.pdf

EDIT: @kentanghk a little snippet here may confirm what we said about the Konica acetic acid bleach actually doing some fixing:

"These results indicate that the solution of U.S. Pat. No. 4,277,556 performed both a bleaching and a fixing function, but did not clean-out to completion."

This is from Kodak researchers.

kentanghk · Jan 18, 2021

relistan said:
The following citric acid bleach works but is slow:

3% hydrogen peroxide — 20ml

citric acid — 0.5g

zinc sulfate — 0.6g

sodium bicarbonate to pH about 4

20 minutes @ 30C

@relistan Is the zinc sulphate you used monohydrate or heptahydrate? I tried to replicate your work today but I can't make it work even at 38C for 20 minutes. I used sodium hydroxide for pH adjustment and I am thinking if that affected the bleaching.

relistan said:
EDIT: @kentanghk a little snippet here may confirm what we said about the Konica acetic acid bleach actually doing some fixing:

"These results indicate that the solution of U.S. Pat. No. 4,277,556 performed both a bleaching and a fixing function, but did not clean-out to completion."

This is from Kodak researchers.

So acetic acid bleach can actually fix our image. That explains the lower Dmax.

I ran some test on the citric acid-silver nitrate bleach today to see if I can use less silver. It seems to work at 0.08g/L silver nitrate but the bleaching is slower.

relistan · Jan 18, 2021

kentanghk said:
Is the zinc sulphate you used monohydrate or heptahydrate? I tried to replicate your work today but I can't make it work even at 38C for 20 minutes. I used sodium hydroxide for pH adjustment and I am thinking if that affected the bleaching.

Oh bummer. Sorry I didn't know it was available in other forms. It's anhydrous. So that might be why it didn't work? I was suspicious of pollutants in my NaOH so that's why I didn't use that. Maybe try with carbonate or bicarbonate and the appropriate amount of your zinc sulfate to match the anhydrous amount? Extra doesn't seem to hurt, but there is a point where it no longer makes it faster.

kentanghk said:
So acetic acid bleach can actually fix our image. That explains the lower Dmax.

Yes! It seems that way.

kentanghk said:
I ran some test on the citric acid-silver nitrate bleach today to see if I can use less silver. It seems to work at 0.08g/L silver nitrate but the bleaching is slower.

Wow that is a lot less. How long did it take?

Helinophoto · Jan 18, 2021

So, where are we in this method?
Have we moved away from the "kitchen sink", to the "get on the terror-list for buying bomb-making chemicals"?

I tried the original method here and it worked just fine on Foma 100.

But, if it needs 10 chemicals that will put you on a watch list, and cost $1000, then maybe a commercial kit is better?

I don't have a projector anyway, so I just did it as an experiment.

relistan · Jan 19, 2021

Helinophoto said:
So, where are we in this method?
Have we moved away from the "kitchen sink", to the "get on the terror-list for buying bomb-making chemicals"?

I know this is joke, but seriously we have tried to keep it to safer chemicals that you can easily get.

Helinophoto said:
I tried the original method here and it worked just fine on Foma 100.

But, if it needs 10 chemicals that will put you on a watch list, and cost $1000, then maybe a commercial kit is better?

I don't have a projector anyway, so I just did it as an experiment.

Good to hear that it works with Fomapan 100 as well as the 400 I have run.

If you just want a commercial kit, sure you can buy one. You can also mix up a permanganate bleach like the one in the ADOX kit yourself. If that's all a person wants, they should just buy it. No kits are cheap, however, with the Foma kit being the cheapest. Certainly not as cheap as a bit of peroxide and some other simple chemicals.

So as I posted and demonstrated, the original bleach from Kelly-Shane Fuller works well for some films. Fomapan films and Ilford FP4 seem to work fine. He seems to use it with JCH Street Pan and it works.
There are some notable limitations:

It does not work AT ALL for at least two dedicated slide films: Fomapan R100 and ADOX Scala 160. Both are too damaged by the reaction, probably driven by the amount of silver present
It can produce quite significant yellow staining under certain circumstances, or depending on the ingredients used
It produces some blistering of the emulsion in some films more than others
The bleach becomes faster as it sits, or after some amount of film has been run, so you must always bleach by inspection unless it's the first time the bleach was used
It turns out it is not a bleach, it's a blix, so you will have some amount of loss of silver halide before the second developer, and that means it's hard to get a good deep the Dmax like you could with bichromate, permanganate, or copper sulfate bleach (or peroxide bleach using other chemistry than acetic acid)

Given all of that, it can produce some very nice results with the right film!

But we have been seeing if it's possible to get a mixture that supports more films, better.

Lachlan Young · Jan 19, 2021

relistan said:
I know this is joke, but seriously we have tried to keep it to safer chemicals that you can easily get.

relistan said:
But we have been seeing if it's possible to get a mixture that supports more films, better.

Except you haven't really - the permanganate bleach that Adox use is at a dilution that requires no hazard labeling, claims a decent lifespan and works with a variety of films, whereas the best that has been achieved in this thread is a succession of very partial and limited successes on a narrow range of emulsions - and has illustrated clearly why peroxide bleaches seem not to have gone beyond the defensive patents filed in the 1990s. Surely a better approach might be to see what the minimum amount of acidification a permanaganate + manganese sequestrant based bleach needs to act in a reasonable timeframe?

The kits are expensive because the market is a subset of a subset. That anyone makes them at all is remarkable.

relistan · Jan 19, 2021

Lachlan Young said:
Except you haven't really - the permanganate bleach that Adox use is at a dilution that requires no hazard labeling, claims a decent lifespan and works with a variety of films, whereas the best that has been achieved in this thread is a succession of very partial and limited successes on a narrow range of emulsions - and has illustrated clearly why peroxide bleaches seem not to have gone beyond the defensive patents filed in the 1990s. Surely a better approach might be to see what the minimum amount of acidification a permanaganate + manganese sequestrant based bleach needs to act in a reasonable timeframe?

I was not comparing to that bleach. I was comparing to the original peroxide bleach. I don't understand why folks continue to advocate that nobody should bother to try anything. Worst case you learn something. Best case you find something useful.

I agree that there are probably other approaches that are better at this point. Murray Kelly's bleach in the other thread is interesting, for example. But I don't think we've plumbed this well enough to know there is not something good sitting there. I've invested enough time and money and some of my new chemistry just arrived after waiting some weeks and so I intend to finish the work I started. I don't know if we'll find anything. If not then this thread is there for others to learn. I know at least 100x more now than I did a month ago. And we have two decent bleaches, including the one @kentanghk made with citric acid.

I've got a couple more weekends I'm willing to put into it.

Lachlan Young said:
The kits are expensive because the market is a subset of a subset. That anyone makes them at all is remarkable.

Sure and I was not complaining. I was responding to his comment about needing to spend money on chemistry. I love ADOX products, for example, and applaud them offering it.

YoIaMoNwater · Jan 19, 2021

Lachlan Young said:
Except you haven't really - the permanganate bleach that Adox use is at a dilution that requires no hazard labeling, claims a decent lifespan and works with a variety of films, whereas the best that has been achieved in this thread is a succession of very partial and limited successes on a narrow range of emulsions - and has illustrated clearly why peroxide bleaches seem not to have gone beyond the defensive patents filed in the 1990s. Surely a better approach might be to see what the minimum amount of acidification a permanaganate + manganese sequestrant based bleach needs to act in a reasonable timeframe?

The kits are expensive because the market is a subset of a subset. That anyone makes them at all is remarkable.

Lachlan, I'm not sure what you're trying to accomplish here by dismissing OP and other's experimental work with H2O2 bleach. Why can't we have fun experimenting with something that's not commonly used for reversal processing? You have recommended using PEG as an accelerator but I have yet to see any results from you. Science isn't easy as 1, 2, 3, so coming in here and saying OP haven't really made his formula to work for all types of film is just ridiculous. You can go buy kits yourself but there's no reason to shut down anyone that's trying to have fun experimenting.

Helinophoto · Jan 21, 2021

relistan said:
The bleach becomes faster as it sits, or after some amount of film has been run, so you must always bleach by inspection unless it's the first time the bleach was used

I have a question about the inspection part, since I am new to this process.
When I did my Foma-film, and bleached as per instruction, I could see a faint image on the film-strip after bleaching.
The resulting final images were ok after the second developer (a little dark, perhaps, but very very usable).

When you bleach by inspection, what exactly are you looking for?
Totally uniform (cloudy) negatives with no visible traces of an image?

I would likely try this again (I kept the hydrogen-peroxide + vinegar solution in a bottle here), but it would probably help to know what to look for during bleaching.

Also, the first development-phase, is the point here to "develop to completion" almost, or overdevelop -a lot-, for the bleach to clear/brighten the final image enough for the second developer to create as normal negatives as possible?

Donald Qualls · Jan 21, 2021

Depending on how you're looking at your film, you might see a faint negative image (film base and whatever is behind it as dark, milky halide as light) or a weak positive (light behind the film, so the halide is seen as blocking that light). Either way, the bleached film leader (assuming 35mm) should be as clear as fixed-out, undeveloped film of the same type.

relistan · Jan 21, 2021

Helinophoto said:
I have a question about the inspection part, since I am new to this process.
When I did my Foma-film, and bleached as per instruction, I could see a faint image on the film-strip after bleaching.
The resulting final images were ok after the second developer (a little dark, perhaps, but very very usable).

When you bleach by inspection, what exactly are you looking for?
Totally uniform (cloudy) negatives with no visible traces of an image?

I would likely try this again (I kept the hydrogen-peroxide + vinegar solution in a bottle here), but it would probably help to know what to look for during bleaching.

Also, the first development-phase, is the point here to "develop to completion" almost, or overdevelop -a lot-, for the bleach to clear/brighten the final image enough for the second developer to create as normal negatives as possible?

Like @Donald Qualls says, with light behind it at all you should see a positive image and the leader should be totally clear. Here's what ADOX Silvermax looked like when bleached fully, and before re-exposure. It has a reddish pink cast. Fomapan 400 is yellow/cream.

See that the film leader is still wrapped around the reel and that it's totally clear. Note that if you did not develop long enough in the first developer, you will not see a fully clear leader and that's one way to know. With this bleach I usually bleach in normal room light the whole time, and you start to know what the film looks like when it's bleached without having to unspool it. Usually the last place to clear is between the sprocket holes. If there are still darker spots there, keep bleaching.

Regarding first developer, you want to develop long enough to give clear highlights, but not enough to start giving general fog, because that would reduce density all over the image. I have found that a clear leader after bleaching is a good indication that it has been developed long enough. You want to develop just long enough to do clear it, maybe a little extra. For me, with this bleach, that gives good results.

This bleach has a reasonably strong fixing action so I found it mostly unnecessary/undesirable to use much solvent in the first developer. The Fomapan 400 does not need it and can't really handle it. Silvermax does need a bit, but it blisters too much to use in this bleach, so not worth thinking about.

Helinophoto · Jan 22, 2021

Thanks for the information,

My Foma 100 looked like this after bleaching, maybe the faint image is too visible here?

Donald Qualls · Jan 22, 2021

That actually looks pretty good to my eye. I haven't done a bunch of reversal, but it looks like you've gotten rid of the silver image. Fogging and redeveloping is what will finally tell the tale.

relistan · Jan 22, 2021

Helinophoto said:
My Foma 100 looked like this after bleaching, maybe the faint image is too visible here?

That looks reasonably good. But, is that a positive image or a negative? It looks like a negative still? Did any part of the film end up nearly clear?

Helinophoto · Jan 22, 2021

relistan said:
That looks reasonably good. But, is that a positive image or a negative? It looks like a negative still? Did any part of the film end up nearly clear?

Not 100% clear, a little dark, this is a screenshot of a video I did, where it basically just hangs in the shower in a well-lit bathroom.

And here is the resulting positive scan of the redeveloped horse statue-image from the bleached photo above, as it would be displayed by a projector.

Mind the mess on the film, I managed to actually drop the thing onto the bathroom-floor while drying (newbie mistake), the clips suddenly let go as I was inspecting it.
A scan is perhaps not the best representation though because it is so easy to adjust and correct it.
But, as a process, it does give very usable images, when it works, (I tried the same on some expired Kodak Tri-x 320 from 2011, kept frozen, shot at box speed in contrasty sunlight and they were almost black )

Helinophoto · Jan 22, 2021

relistan said:
That looks reasonably good. But, is that a positive image or a negative? It looks like a negative still? Did any part of the film end up nearly clear?

(another part of the video)

This shows that this is a "negative image", but it is explained why, below this post:

The resulting (positive) scan after exposing it to light and redeveloping:
This is a correct representation, with dark wood, grey brick and bright mortar in between.

It is strange that it does look like a negative image on the roll, the photo on the roll is taken after i had bleached it, and was rinsing it, before exposing it to light under a bulb, and then develop it a second time.

Donald Qualls · Jan 22, 2021

What you're seeing that looks like a negative in this view is the dark space between film layers (light limited there by the halide and the reel) as the darks, and the undeveloped halide as the lights. Hold that film up against a light background, and it'll look like a positive, with the halide blocking the transmitted light according to density.

Helinophoto · Jan 22, 2021

Donald Qualls said:
What you're seeing that looks like a negative in this view is the dark space between film layers (light limited there by the halide and the reel) as the darks, and the undeveloped halide as the lights. Hold that film up against a light background, and it'll look like a positive, with the halide blocking the transmitted light according to density.

That's must be it indeed.
I did not film that part of it, but it must be the case, all the while I actually ended up with positives in the end

Donald Qualls · Jan 22, 2021

You can see more or less the same thing with some developed and fixed negatives, held in a strong front light against a dark background (and this is exactly what happens with a tintype or black glass ambrotype): the silver image (black in the negative) will appear light against the dark background due to scattering light. With ambrotypes made on clear glass, you can lift the glass and see the negative image, or put it on the velvet backing and see the positive.

Here, it looks like a negative because it's the darks that are still white, so to speak...

relistan · Jan 22, 2021

@Helinophoto That looks like you got very good results, I'd say! Given how good the shots look without any real backlighting to speak of, I'd say the process worked quite well. 120 Fomapan 100 should be pretty nice, too, as the base is clear. If you want a clearer highlight (I don't think you need it from what I can tell), you could try adding another minute to the first developer and see if that changes it. Given my experience with Fomapan 400 and this bleach I'd recommend not adding any solvent to the first developer.

Helinophoto · Jan 22, 2021

relistan said:
@Helinophoto That looks like you got very good results, I'd say! Given how good the shots look without any real backlighting to speak of, I'd say the process worked quite well. 120 Fomapan 100 should be pretty nice, too, as the base is clear. If you want a clearer highlight (I don't think you need it from what I can tell), you could try adding another minute to the first developer and see if that changes it. Given my experience with Fomapan 400 and this bleach I'd recommend not adding any solvent to the first developer.

Thanks, yes..........Oh I see I forgot to actually specify the dev, I used HC-110 dilution B all the way here.
I have a bunch of Acros 100 as well, so I may pluck one of those and shoot a test-roll tomorrow.
Not sure if the Hydrogen-peroxide + vinegar solution is still active though, it has been sitting in a closed bottle for a week, crossing fingers. (it's expensive here, €25 for 500ml).

kentanghk · Jan 22, 2021

relistan said:
It's anhydrous. So that might be why it didn't work? I was suspicious of pollutants in my NaOH so that's why I didn't use that. Maybe try with carbonate or bicarbonate and the appropriate amount of your zinc sulfate to match the anhydrous amount? Extra doesn't seem to hurt, but there is a point where it no longer makes it faster.

I will try with carbonate but I am suspecting my zinc sulphate contains quite a bit of impurities. I have some better grade zinc nitrate and maybe I will get it a try.

relistan said:
Wow that is a lot less. How long did it take?

It takes about 3 minutes for the original formula. With 0.08g/L silver nitrate it takes about 7 minutes to completely bleach my test strip.

kentanghk · Jan 22, 2021

@Helinophoto Your reversal looks pretty good! Look like there is no staining on your reversal and I wonder if the staining is more affected by the film stock than bleach formula.

Helinophoto · Jan 23, 2021

kentanghk said:
@Helinophoto Your reversal looks pretty good! Look like there is no staining on your reversal and I wonder if the staining is more affected by the film stock than bleach formula.

Yes, there was no staining, no stains on my successful Foma 100 and no stains on my unsuccessful Kodak Tri-x 320 (the tri-x had photos, but was way dark, but this may be related to the fact that I reused the HC-100B for this film, after using it on the Foma-film).

I did wash it pretty properly between dev - bleach - exposing to light - and redevelop.
The Hydrogen-peroxide solution is a 3% pharmacy-grade "mouth rinse" solution, which contain no traces of other chemicals and the vinegar was regular 7% white vinegar from the supermarket.

B&W Reversal with Hydrogen Peroxide

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