You need more Dektol stock and less water. I used two parts Dektol stock to one part water and 12 minutes, with good results.
Copper Sulphate B&W Reversal Bleach
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You need more Dektol stock and less water. I used two parts Dektol stock to one part water and 12 minutes, with good results.
Hey, good progress. This is nice and lacking in stain and looks quite even. So you are on the right track. Bleach time may be close to right and second developer may be close as well.
I suggest you get a little sodium thiosulfate crystals and add 1g per liter to your first developer. (NOTE do not put this in the second developer). This won’t affect pH noticeably because it’s neutral as @Anon Ymous said. It will lighten your highlights. You may need to then adjust dev time a bit, too. The slide should not be so dark that you can’t just hold it up and look at it.
Well, I don’t have any hypo powder at the moment, so I’m just using straight dev. This was 12 minutes in HC-110 A, and I think it could use a bit of extra dev time. Gonna shoot a roll at 100 ISO and dev for 14-16 mins in HC-110 A tomorrow.
Hello! I'm working on replacing ammonia as the second bath for this reversal method using a copper rehal solution.
The exposure was not good, I shot a test roll for another purpose, but it shows that the idea works.
Instead of an ammonia-selective fixer, I use a concentrated calcium chloride fixer, a new version of a salt fixer. It uses 750g of calcium chloride in one liter of water and works in 15min at 35ºC.
The exposure was not good, I shot a test roll for another purpose, but it shows that the idea works.
Instead of an ammonia-selective fixer, I use a concentrated calcium chloride fixer, a new version of a salt fixer. It uses 750g of calcium chloride in one liter of water and works in 15min at 35ºC.
Very interesting, thanks!
Interesting. Does this work very well on non-reversal frames? If you haven't already perfected it there, I'd try that first since there are so many variables to consider in reversal processing.
Bumping this thread as I have a question.
In troubleshooting my process, I have discovered something rather odd. My copper sulphate bath rehaligenates the film just fine, if I go from the copper sulphate to a black and white fixer, the film clears right away. But, when I put the film in ammonia, it doesn’t do anything at all! It doesn’t clear or anything. I even tried putting it in the 5% ammonia that comes out of the bottle, no dice. What the heck could I possibly be doing wrong?
In troubleshooting my process, I have discovered something rather odd. My copper sulphate bath rehaligenates the film just fine, if I go from the copper sulphate to a black and white fixer, the film clears right away. But, when I put the film in ammonia, it doesn’t do anything at all! It doesn’t clear or anything. I even tried putting it in the 5% ammonia that comes out of the bottle, no dice. What the heck could I possibly be doing wrong?
In my experience, 5% ammonia is slow, like an hour or more. I used 7-8% and still needed 40 minutes at 38ºC. I moved to calcium chloride, which is still slow but does not smell. And ammonia will not clear all, it will leave AgBr I think that is what you are seeing.
To be clear, what I am doing is developing the film fully in the first developer after it has been exposed to room light. Then,I am bleaching in copper sulphate, and attempting to remove any rehalogenated salts with ammonia, but it is not clearing. I know they are being rehalogenated as when I put the same film into fixer it clears almost immediately.
Reduces, right?
Yes, but would it do that if there were bromide ions present from carryover? (But chloride ions are more electronegative, so I'm not sure it would make a difference if there also was some bromide.)
I hope someone who is using the bleach has an idea of what's going on. Good luck.
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So you are rehaling a black film, right? Ammonia is slow when half of the silver is removed if an image is present. If you are trying to remove all the silver with ammonia you will need to increase time, concentration, or temperature.
Sounds like you haven't actually bleached it. Ammonia will only dissolve silver chloride (that's the principle of this bleach) and you must still have mostly bromides and iodides. That would happen if the bleach didn't bleach. Check acidity, time, and amount of sodium chloride.
What film are you using? Is it a film normally used in camera or is it a "process" film, a film used for making internegatives or projection prints? I ask as my attempt using this method failed when I tried to use ECP-2 projection film as a black and white reversal film. It seems that this film was a AgCl based emulsion so was completely incompatible with this selective fixing process.
Bumping this thread.
I have spent the last week or so reading this thread. First, I'm going to summarize key details in one post, bot for myself and future readers. But I do have a few questions at the end.
For me film reversal is relevant in the context of cyanotype. I currently use the "interpositive" method where I enlarge a photo to RC paper, contact print that to an ortho litho sheet film to make a large negative, and contact print that to make the cyanotype
For me, film reversal would be another way to get that large negative. The ortho litho films I have are Arista Ortho Litho Film and Inkpress Regent Royal Hard Dot Film.
(1) General Workflow:
(aggregating posts #27, #38, #73, and #87)
(2) Sodium Sulfite Working Solution:
(post #247)
Water ................... 800 ml
Sodium sulfite .......... 20 g
Water to 1L
(3) Standard Bleach (Working Solution):
(post #8 and external link to Tim Rudman's "The Master Photographer’s Lith Printing Course", now out of print).
Water ...................................... 800 ml
Copper (II) (Cupric) Sulfate................ 50 g
Concentrated Sulfuric Acid (EXTREME CARE!).. 6.5 ml
Sodium Chloride (Common Salt)............... 50 g
Water to make 1 L
You can use lower concentrations of sulfuric acid and adjust the volume. For example, battery acid is 30% sulfuric acid (post #214) so 6.5 ml becomes 22 ml. Drain cleaner is also an option.
(4) Citric Acid Variant (Working Solution):
Sulfuric acid is not an active ingredient, you just need a low pH to get copper chloride to react with metallic silver (post #228). This has encouraged @relistan and others to experiment with citric acid as milder alternative, suggesting the following recipe (post #73):
Water ...................................... 800 ml
Copper (II) (Cupric) Sulfate................ 50 g
Citric Acid (99.9%)......................... 10 g
Sodium Chloride (Common Salt)................ 50 g
Water to make 1 L
However, these efforts have had limited success and so far seem to result in staining and low Dmax (post #209).
Commentary: My understanding is that the issue is that citric acid is weaker than sulfuric. If that is the case, I might experiment with sulfamic acid. It's sold as a cleaner and if you do cyanotype you might already be using it to acidify buffered papers.
(5) Ammonium Chloride Variant (Working Solution):
(post #162)
Use ammonium chloride instead of sodium chloride. The bleach still has copper chloride to react with the silver, but also contains ammonium hydroxide. As silver chloride forms, it dissolves into the bleach itself and does not need a separate ammonia bath (post #162). But you still need the sodium sulfite bath. Best results were obtained with this formula:
Water ...................................... 800 ml
Copper (II) (Cupric) Sulfate................ 50 g
Citric Acid (99.9%)......................... 30 g
Ammonium Chloride ........................... 70 g
Water to make 1 L
Citric acid can be omitted, but with worse performance (slower bleach, more base fog).
Performance is film-dependent (post #172) and there's a risk that the ammonia hydroxide may react with sodium sulfite to make copper hydroxide (post #174), killing the active ingredient.
(6) External Variant / Ferric Chloride (Working Solution):
This variant has not been discussed here yet, but is totally based on the same principles. I found it on this YT video by Analog Resurgence (skip to 14:15).
The bleach is pure ferric chloride diluted 1+1. That is all. The mechanism is the same: Convert metallic silver into AgCl and dissolve it in ammonia. The video switches the order of the ammonia and clearing baths and the clearing bath is sodium metabisulfite instead of sulfite.
---- Q: Any idea why you'd replace sodium sulfite with metabisulfite?
Ferric chloride is used in electronic stores as a copper etchant (e.g. to make PCBs) and it is also available on Amazon.
(7) Making Adjustments:
The key variables are the initial exposure of the film and the 1st development time. In post #255, @Donald Qualls says:
"Either underexposure or underdevelopment in the first dev will result in dark final slides. If the slide is dark and there's not much separation between lights and darks, it's prob underdeveloped; if the separation is good, but everything is too dark, it's likely underexposed. If you can't be sure which, it's probably both, so start with increasing first development, then adjust exposure"
Another option to lighten the final positive overall, especially in the highlights, is to add 1 g/L of sodium thiosulfate to the first developer (post #277).
Comments: Another option is to "flash" the film, thought that is mainly for sheet film. This article by Liam Lawless has a lot to say about using a flash exposure to control contrast in the context of enlarged negatives via "classic" film reversal with potassium dichromate or permanganate.
(1) Can someone clarify for me what the sodium sulfite bath is for?
Post #265 says that it's to remove the silver citrate. That sounds like its only needed if you use citric acid for the bleach, but that can't be the full story because sulfite is also used in the original post with sulfuric acid. Post #39 says that without sodium sulfite you risk staining. Post #87 says that skipping sodium sulfite had no detrimental effect.
The YT video I linked above says that without the clearing bath, the film will be stained and look kind of sepia. But that might be specific to ferric chloride and may not be true for copper chloride.
So... I'm confused... What exactly gets removed by the sodium sulfite clearing bath?
(2) Why do some clearing baths use sodium sulfite and others metabisulfite?
I notice that film reversal with dichromate also uses sodium sulfite, just like the copper chloride one discussed in this thread. But bleach with potassium permanganate is cleared with sodium metabisulfite, as is the one with ferric chloride above.
(3) Does anyone know if any of my ortho litho films (Arista Ortho Litho vs Inkpress Regent Royal) are compatible or incompatible with this reversal process?
@Quiver2 said that some "process" films used for making internegatives might have an emulsion with AgCl, which is completely incompatible with this process. I do not know if ortho films fall into that category.
(4) Why do some posts suggest a paper developer for the first developer?
For example, posts #255 and #276 suggest Dektol 2+1.
I have spent the last week or so reading this thread. First, I'm going to summarize key details in one post, bot for myself and future readers. But I do have a few questions at the end.
My Context:
For me film reversal is relevant in the context of cyanotype. I currently use the "interpositive" method where I enlarge a photo to RC paper, contact print that to an ortho litho sheet film to make a large negative, and contact print that to make the cyanotype
For me, film reversal would be another way to get that large negative. The ortho litho films I have are Arista Ortho Litho Film and Inkpress Regent Royal Hard Dot Film.
Summary of The Reversal Process:
(1) General Workflow:
(aggregating posts #27, #38, #73, and #87)
- First developer.
- Stop bath.
- Bleach solution --- 5 min
- Sodium sulfite solution --- 2 min
- Undiluted store bought household ammonia --- 2 min
- ----- Q: Is this when I use the room lights fog the film?
- Wash.
- Develop again.
- Wash.
- Fix.
(2) Sodium Sulfite Working Solution:
(post #247)
Water ................... 800 ml
Sodium sulfite .......... 20 g
Water to 1L
(3) Standard Bleach (Working Solution):
(post #8 and external link to Tim Rudman's "The Master Photographer’s Lith Printing Course", now out of print).
Water ...................................... 800 ml
Copper (II) (Cupric) Sulfate................ 50 g
Concentrated Sulfuric Acid (EXTREME CARE!).. 6.5 ml
Sodium Chloride (Common Salt)............... 50 g
Water to make 1 L
You can use lower concentrations of sulfuric acid and adjust the volume. For example, battery acid is 30% sulfuric acid (post #214) so 6.5 ml becomes 22 ml. Drain cleaner is also an option.
(4) Citric Acid Variant (Working Solution):
Sulfuric acid is not an active ingredient, you just need a low pH to get copper chloride to react with metallic silver (post #228). This has encouraged @relistan and others to experiment with citric acid as milder alternative, suggesting the following recipe (post #73):
Water ...................................... 800 ml
Copper (II) (Cupric) Sulfate................ 50 g
Citric Acid (99.9%)......................... 10 g
Sodium Chloride (Common Salt)................ 50 g
Water to make 1 L
However, these efforts have had limited success and so far seem to result in staining and low Dmax (post #209).
Commentary: My understanding is that the issue is that citric acid is weaker than sulfuric. If that is the case, I might experiment with sulfamic acid. It's sold as a cleaner and if you do cyanotype you might already be using it to acidify buffered papers.
(5) Ammonium Chloride Variant (Working Solution):
(post #162)
Use ammonium chloride instead of sodium chloride. The bleach still has copper chloride to react with the silver, but also contains ammonium hydroxide. As silver chloride forms, it dissolves into the bleach itself and does not need a separate ammonia bath (post #162). But you still need the sodium sulfite bath. Best results were obtained with this formula:
Water ...................................... 800 ml
Copper (II) (Cupric) Sulfate................ 50 g
Citric Acid (99.9%)......................... 30 g
Ammonium Chloride ........................... 70 g
Water to make 1 L
Citric acid can be omitted, but with worse performance (slower bleach, more base fog).
Performance is film-dependent (post #172) and there's a risk that the ammonia hydroxide may react with sodium sulfite to make copper hydroxide (post #174), killing the active ingredient.
(6) External Variant / Ferric Chloride (Working Solution):
This variant has not been discussed here yet, but is totally based on the same principles. I found it on this YT video by Analog Resurgence (skip to 14:15).
The bleach is pure ferric chloride diluted 1+1. That is all. The mechanism is the same: Convert metallic silver into AgCl and dissolve it in ammonia. The video switches the order of the ammonia and clearing baths and the clearing bath is sodium metabisulfite instead of sulfite.
---- Q: Any idea why you'd replace sodium sulfite with metabisulfite?
Ferric chloride is used in electronic stores as a copper etchant (e.g. to make PCBs) and it is also available on Amazon.
(7) Making Adjustments:
The key variables are the initial exposure of the film and the 1st development time. In post #255, @Donald Qualls says:
"Either underexposure or underdevelopment in the first dev will result in dark final slides. If the slide is dark and there's not much separation between lights and darks, it's prob underdeveloped; if the separation is good, but everything is too dark, it's likely underexposed. If you can't be sure which, it's probably both, so start with increasing first development, then adjust exposure"
Another option to lighten the final positive overall, especially in the highlights, is to add 1 g/L of sodium thiosulfate to the first developer (post #277).
Comments: Another option is to "flash" the film, thought that is mainly for sheet film. This article by Liam Lawless has a lot to say about using a flash exposure to control contrast in the context of enlarged negatives via "classic" film reversal with potassium dichromate or permanganate.
My Questions:
(1) Can someone clarify for me what the sodium sulfite bath is for?
Post #265 says that it's to remove the silver citrate. That sounds like its only needed if you use citric acid for the bleach, but that can't be the full story because sulfite is also used in the original post with sulfuric acid. Post #39 says that without sodium sulfite you risk staining. Post #87 says that skipping sodium sulfite had no detrimental effect.
The YT video I linked above says that without the clearing bath, the film will be stained and look kind of sepia. But that might be specific to ferric chloride and may not be true for copper chloride.
So... I'm confused... What exactly gets removed by the sodium sulfite clearing bath?
(2) Why do some clearing baths use sodium sulfite and others metabisulfite?
I notice that film reversal with dichromate also uses sodium sulfite, just like the copper chloride one discussed in this thread. But bleach with potassium permanganate is cleared with sodium metabisulfite, as is the one with ferric chloride above.
(3) Does anyone know if any of my ortho litho films (Arista Ortho Litho vs Inkpress Regent Royal) are compatible or incompatible with this reversal process?
@Quiver2 said that some "process" films used for making internegatives might have an emulsion with AgCl, which is completely incompatible with this process. I do not know if ortho films fall into that category.
(4) Why do some posts suggest a paper developer for the first developer?
For example, posts #255 and #276 suggest Dektol 2+1.
1) As I understand it, a sulfite clearing bath for copper chloride based bleach systems is a carry-over from the more traditional dichromate and permanganate bleaches; as an anti-oxidant, it does a very good job neutralizing the strong oxidizers commonly used to bleach developed silver. I don't know of any reason it would be required for a bleach that doesn't use a strong oxidizer.
2) This is almost certainly a matter of pH control. Sodium sulfite is alkaline enough to act as the accelerator in some developers, while metabisulfite is very weakly acidic.
3) I'd be very surprised if ortho films were based on silver chloride. AgCl is sensitive only to deep blue and UV, and very slow (slower even than ortho litho films, which are commonly similar speed to enlarging paper). Some contact printing papers used silver chloride, but I don't know of any of those still being manufactured.
4) First developer for reversal is typically taken far past the "normal" contrast point, and a highly active developer (like low-dilution Dektol) can get there with less time spent than something like HC-110 or D-76.
2) This is almost certainly a matter of pH control. Sodium sulfite is alkaline enough to act as the accelerator in some developers, while metabisulfite is very weakly acidic.
3) I'd be very surprised if ortho films were based on silver chloride. AgCl is sensitive only to deep blue and UV, and very slow (slower even than ortho litho films, which are commonly similar speed to enlarging paper). Some contact printing papers used silver chloride, but I don't know of any of those still being manufactured.
4) First developer for reversal is typically taken far past the "normal" contrast point, and a highly active developer (like low-dilution Dektol) can get there with less time spent than something like HC-110 or D-76.
Adox Lupex
Are we sure it's still in production?
Thanks!
Is ferric chloride a strong oxidizer? The YT video says that the clearing bath is "very important" but doesn't go into details.
In the context of a clearing bath for this specific type of reversal process that turns Ag into AgCl, do you think it matters whether you use sodium sulfite or metabisulfite? Your comment above seems to say that the clearing bath probably doesn't do anything anyway.
Thanks!
Are paper developers, as a group, more active than film developers? I have Ilford Multigrade.
Not the way potassium dichromate or potassium permanganate are. I'm not actually a chemist, but I think the ferric chloride works by providing a combination of ions that can react to convert metallic silver to silver chloride, which is technically oxidation -- but ferric chloride wouldn't be something I'd consider an oxidizer for, for instance, rocket propellant.
I don't know that it does do anything in a copper sulfate/copper chloride/ferric chloride bleach system. But see above; I'm not a chemist, I just have an inkling...
Generally, they are. Most have similar print development times (one to three minutes), and some (Dektol, PQ Universal, and probably most once you know how much) can be diluted for film development -- Dektol is used at 1+1 or 1+2 for prints, but 1+9 for film. Dektol uses carbonate alkali, vs. D-76/ID-11 with borax; carbonate will have a higher pH so the developing agent will be more active.
Thanks!
The article by Liam Lawless says what you said, so I must have read it at some point in the past but I evidently did not retain that information. The article has useful details (at least for me):
Last edited:
No idea, bit still in stock at Fotoimpex.
Copper Sulphate bleach paper doesn't work well with Chloro-Bromide papers as well. It removes some unexposed halides resulting in poor DMax after the second development. Those who shoot photographic paper in camera and want to reversal process it must avoid using Copper Sulphate bleach. Dichromate and Permanganate bleach work best for this application though some of have had success with Peroxide-Citric Acid bleach.
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