BW reversal options

G'day Shawn,

You'd asked what film/s are used. I use the 120 roll Shanghai GP3 film as it has a clear base, and I also run 16mm cine that is the Foma R100 you mention. I have tried Foma 35mm and 120 roll film and even though it has a dull grey base but I barely notice this when projected.

Included two images, one of the Shanghai (6x6) the other of Foma (6x7).

I use a chemistry that is identical to Existing light's but for the bleach which is identical to Mike Wilde's formulation. My fogging is 8 mins (4 per side) in daylight.

I went through a great deal of lost rolls before I was comfortable running the real thing through a process I'd get usable results from. Which leads me to concur with Dr5's comments make sure the chemicals are pure/fresh. I tried using old/cheap raw chemistry and it cost me a lot of wasted time.

Hope this is of some use.

Existing Light said:

In reguard to using battery acid from auto stores, how does that compare to the stuff PF sells? The battery acid is more dilute, in the range of 50%, while the PF stuff is around 98%, right? What about impurities in regular battery acid that might not be present in the PF acid? And doesnt PF require a DEA license to be able to purchase sulfuric acid?

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The stuff I got from PF is 48%, and I think that is all they sell. AFAIK, battery acid is 33%, I think. So it should be just fine. I can't speak on purity, but I know people use it.

And no, you don't need a DEA license by any means. You only need to fill out a DEA form, which takes like 10 minutes tops and all it means is that PF will file it away, so if the DEA ever investigates them, they are up to spec on their records. It's nothing to worry about, takes a few minutes, and no you're not in some FBI database thereafter.

Solution % Help

After some bad math last night, I came to the conclusion that I needed to add 380mL of sulfuric acid to 570mL of water. Luckily this seemed absurd to me and I am happy to report that I do not look like the Joker from Batman....

But seriously, I need help with solution percentages.

First off, I'm using deep tanks which have a capacity of 1900mL (wasteful, I know).

I have 48% sulfuric acid.

My bleach is going to be a 2 part bleach; A is 13g of K-dichromate and 950mL of water, B is going to be ____mL sulfuric acid & ____mL water, for a total of 950mL. Add equal parts to get 1900mL of bleach.

In short, what percentage of acid do I want in my bleach? Ilford says "10% concentrated sulfuric acid". As I understood that, it means for my 48% acid I'll need ≈20% in the final solution to get 10% concentrated (≈98%). However, that brings me to an amount of about 380mL of acid, and every account I've seen doesn't add more than 20mL per liter, whether it's battery acid or what.

What am I missing? It seems like I actually need a 1% solution of concentrated sulfuric acid...

holmburgers said:

The stuff I got from PF is 48%, and I think that is all they sell. AFAIK, battery acid is 33%, I think. So it should be just fine. I can't speak on purity, but I know people use it.

And no, you don't need a DEA license by any means. You only need to fill out a DEA form, which takes like 10 minutes tops and all it means is that PF will file it away, so if the DEA ever investigates them, they are up to spec on their records. It's nothing to worry about, takes a few minutes, and no you're not in some FBI database thereafter.

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I'm quite sure I found a distributor that sold more concentrated sulfuric acid than 48% (but I could be delusional). Obviously I assumed wrong that it was PF. I might look in to getting the DEA form. The PErmanganate bleach works fine for me, and the distributor I used was ScienceCompany.com, I believe. They didnt require any DEA stuff for me to get it, but PF does. Seems like it's more trouble than it's worth for me to order from PF that required a DEA form when science company doesnt. I did buy the sodium bisulfate and sodium metabisulfite from them, though. Maybe I'll get a DEA form when I get tired of paying shipping from two sources

For what it's worth, supporting Photoformulary over some generic science company is a noble cause; consider it a moral tax write off.

I'm not sure, but perhaps once you fill it out, you don't need to do it again. Not sure though, worth asking.

Existing Light said:

I did buy the sodium bisulfate and sodium metabisulfite from them, though. Maybe I'll get a DEA form when I get tired of paying shipping from two sources

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In your original formula /process posting, you mentioned 'sodium metabisulfite' and 'sodium metabisulfate' and here you mention 'sodium bisulfate'.
I'd like to try your method, but could you please clarify exactly what chemicals you use, please?.

Thanks very much,

Steve

The Bisulphate can be used in place of Sulphuric acid, you still need Metabisulphite to clear the bleach, if potassium permanganate is used.

Ian

Steve Roberts said:

In your original formula /process posting, you mentioned 'sodium metabisulfite' and 'sodium metabisulfate' and here you mention 'sodium bisulfate'.
I'd like to try your method, but could you please clarify exactly what chemicals you use, please?.

Thanks very much,

Steve

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oops, thanks for catching that.

The bleach is two parts (two seperate solutions): potassium permanganate (4 grams and one liter of distilled water), and Sodium bisulfate (54.5 grams plus one liter of water)

The clearing bath is sodium metabisulfite (30 grams plus one liter of water)


I try to check for spelling mistakes, but sometimes something slips by.

if you wanna doublecheck the chemicals I use, here's the link again http://www.angelfire.com/wi/spqrspqr/photo/bwreversal.html . I do use the chemicals in this article, but I dont follow the developing instructions to the letter, nor do I perfectly follow the Ilford processing method. This is obiouslt something that has to be tinkered with. BTW, this article says to add enough water to make a liter of whatever chemical that's being mixed: I simply add one liter of water; having the chemicals slightly dilute doesnt affect performance, IME. I've even came across one instance where the process peeled the emulsion off the film base. I'm wanting to think diluting the bleach solved or significantly improved the situation, but I'm not sure. I'll see if I can find the thread with the Flickr link

I'd like to mention something that caught my attention long after the fact... on the issue of reusing the 1st developer as the 2nd developer, it occurred to me that this would be a bad idea if you have hypo in your first dev.

And by the way; could a reversal procedure be used on paper? Positives prints from your b&w slides anyone??

holmburgers said:

I'd like to mention something that caught my attention long after the fact... on the issue of reusing the 1st developer as the 2nd developer, it occurred to me that this would be a bad idea if you have hypo in your first dev.

And by the way; could a reversal procedure be used on paper? Positives prints from your b&w slides anyone??

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There are recipes that use hypo in the first developer. I'm not sure why, really. MAybe to help with the fogging issue which I dont seem to be having? I believe ilford suggests using hypo in the first developer, but I'm having trouble opening PDFs on my computer now, so I cant check.

You probably could use a reversal process with paper. There is a reversal black and white paper that will make positives of your positives. If you can get hold of that for a reasonable price, you might could save yourself some time and trouble and money figuring out how to get consistent results reversal processing paper. I havent tried doing that, but it sounds fun

I'm mainly just curious if it would work well with paper. Perhaps once I've done some film, I'll use the chems for paper before tossing 'em.

As for the hypo in the first dev, it's purpose is to "clear the highlights". I've read accounts where it is necessary, and others where it is not, depending on usage and personal preference. If you're scanning, I'm sure it's not a problem; but if you're looking for sparkling projections, it probably helps get you there.

I think a good plan is to start low and work your way up. My interpretation is that it eats away the halide that remains unexposed in your heavy negative density areas (highlights). It's affect is probably nominal on the completely unexposed, shadow regions, but since most of the highlights are now heavy in metallic silver, the small amount of remaining halide in those areas is easily removed by the hypo, leaving little to no halide to be developed into highlight fog in your 2nd dev.

Maybe not the best explanation, but I believe that is what's happening.

Existing Light said:

... There is a reversal black and white paper that will make positives of your positives. If you can get hold of that for a reasonable price, you might could save yourself some time and trouble and money figuring out how to get consistent results reversal processing paper. I havent tried doing that, but it sounds fun

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I haven't tried that either, but think about it... A normal (neg-pos) print looks good because the negative is low contrast, but the paper has much higher contrast. So, combining their contrasts, we get a "normal" result. A reversal processed BW film has higher contrast compared to the negatives. Combined with the high contrast of reversal paper (probably about grade 4 for Ilford's paper) the print will probably be too harsh.

holmburgers said:

I'm mainly just curious if it would work well with paper. Perhaps once I've done some film, I'll use the chems for paper before tossing 'em.

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It works on paper too. I made some trials, but I see some potential problems with papers. First, if you soak paper in the solutions for a long time it is quite difficult to wash it properly and it's crucial to wash very well in reversal process. And if you wash properly the emulsion and gelatine may fall off.
Second, the contrast will be a problem. If you process your slides on some 1.5 gamma and you enlarge it on papers with gamma about 2... but fortunately, there are many ways to decrease contrast of a paper (on the opposite of increasing contrast).

I'd recommend to start with RC, regarding my first point.

holmburgers said:

I'm mainly just curious if it would work well with paper. Perhaps once I've done some film, I'll use the chems for paper before tossing 'em.

As for the hypo in the first dev, it's purpose is to "clear the highlights". I've read accounts where it is necessary, and others where it is not, depending on usage and personal preference. If you're scanning, I'm sure it's not a problem; but if you're looking for sparkling projections, it probably helps get you there.

I think a good plan is to start low and work your way up. My interpretation is that it eats away the halide that remains unexposed in your heavy negative density areas (highlights). It's affect is probably nominal on the completely unexposed, shadow regions, but since most of the highlights are now heavy in metallic silver, the small amount of remaining halide in those areas is easily removed by the hypo, leaving little to no halide to be developed into highlight fog in your 2nd dev.

Maybe not the best explanation, but I believe that is what's happening.

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Give reversal processing paper a shot. It wont hurt anything except a few sheets of paper if it doesnt work out well, and you'd have learned siomething in the process, which is the most important thing. And if it does work, post your process so I can learn from it and not waste any paper

As for the hypo thing, that's what I read as well. I was oversimplifying the explanation when I said "it clears the highlights." I think for most people interested in slides but dont care too much for the technical stuff, that's good enough. (I like the technical stuff, though, even though I dont understand a lot of it )

Anon Ymous said:

I haven't tried that either, but think about it... A normal (neg-pos) print looks good because the negative is low contrast, but the paper has much higher contrast. So, combining their contrasts, we get a "normal" result. A reversal processed BW film has higher contrast compared to the negatives. Combined with the high contrast of reversal paper (probably about grade 4 for Ilford's paper) the print will probably be too harsh.

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That's a valid concern. From what I understand, the slower films like HP5, Delta 400, and Delta 3200 (and the kodak equivalents, of course) are lower in contrast. If you're planning on making prints, using one of these lower contrast films might be an option. I'm not sure how a lower contrast slide would project, so it's probably a tradeoff of projectability and printability. I wish I could get some of the reversal paper to play with, but I cant seem to find it in the States

As per reversal of paper; I wonder how much control VC filters would give you. You could try exposing with a 00 filter and perhaps it would reign in the contrast enough. If I try it out, I'll be sure to post!

Existing Light said:

I try to check for spelling mistakes, but sometimes something slips by.

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Not to worry! Thanks for clarifying that.

Cheers,
Steve

sorry, is in spanish http://www.flickr.com/groups/alicante_analogico/discuss/72157625712862585

I hope you can translate easily.

Well, I got my act together over the weekend, went out and shot a roll of FP4 and tried Existing Light's reversal process. As there seem to be so many tweaks and variations, I didn't follow any part of the process rigidly (especially the second development, when my timer just died after a few seconds!) and so I entered into it in the true spirit of experimentation. I used the stuff I had and where I didn't have something, I used something else! First developer, I used Rodinal, as per the suggestion on the web page link. I didn't make up stock solutions of any of the chemicals, but scaled down the amounts for the capacity of my tank and only made up what I needed. I may have sacrificed some accuracy, but I used an electronic jeweller's balance (the balance is electronic, not the jeweller!) which purports to be accurate to 0.1 grammes, which I though was probably near 'nuff. I've never had so many pots of chemicals lined up at once and made a note to myself that in future I must label them before I use the wrong one at some point. I got the distinct impression that beyond the first development the process is fairly forgiving and that from EL's notes it's generally more important to have too much than too little of most things. Exposing the film to light when it's unfixed and opaque really goes against the grain after forty-odd years of conventional processing. My second (paper) developer was Ilford Multigrade 1 + 9 for about 3 mins (timer died, as mentioned). After the final fix I was a bit concerned to see what appeared to be a black roll of film, but on inspection, only most of it was black!
In the webpage link it suggests that the effective film speed is increased by a couple of stops, but my experience here indicates that film speed is decreased by about that amount. Consequently, most of my exposure variations had been based on underexposing in the camera for effective increased speed and turned out far too dark in the final result. I had taken the precaution of over-exposing some shots and it was those that were best. Plus two stops seemed about right, but in future I'll give it 2 1/2 stops to be sure. Rating FP4 at 25ASA shouldn't be too far out. That brings things back somewhere in the ball park of Agfa Dia-Direct, which was 12ASA IIRC.
Despite the relatively low success rate, I was pleased to get anything at all and will certainly be having another attempt. Unfortunately, at some point there will be an inquisition about how the stainless steel kitchen sink came to be so stained!
Best wishes,
Steve

Thanks for sharing Steve!

On dr5's website, most of their films are recommended at a lower speed than box, so that goes with what you've found.

I believe that on the Ilford write-up, they say that a longer first development results in a lighter image, which makes sense; as you are increasing the density of the negative image, which will be bleached away, yielding a lighter positive image.

How long was your 1st dev? It'd be interesting to repeat your procedure (if possible! ) while extending only the first dev.

I've also done some reversal prints from color slides. Yes it did work... However the emulsion becomes very soft and you have to be super careful. It also changed glossy RC paper to a matte finish . The prints were a bit "muddy" as I didn't have a decent clearing bath at all then. It was when I was starting my darkroom hobby... But it really was worth a try and I'm sure you can get good results by tinkering around a bit.

I ended up using preflash to bring the dark tones visible then but it ruined blacks. I think I'd use different methods today. Sorry about scanner noise in the attachment. But I think this BW version looks much more old-fashioned than the original, modern color slide. Fits the scene.

holmburgers said:

How long was your 1st dev? It'd be interesting to repeat your procedure (if possible! ) while extending only the first dev.

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Hi,
My first dev in Rodinal was 1 + 25, 8 mins at 20 degs C. Those were purely the figures I arrived at when I experimented with Rodinal and FP4 a few years ago. I'm not a regular user of it, so I'll stand by for a blast from established members of the Church Of Rodinal !
As you say, a longer first dev should give a lighter image, so perhaps FP4 @ 25ASA and a minute longer in the Rodinal?
Good luck - I look forward to hearing how you get on.
Steve

The reversal print definitely shows promise!

Steve, I've never used Rodinal, so you're safe from me at least! I think it'd be nice to find what development gives you box speed or nearly so, and then explore pushing/pulling. But that's just me; personally I hope I can get a bit more speed out of reversal processing since my goal is to use b&w positives behind screen-plates (autochrome) which already suck up quite a bit of light.

It'd be interesting to see the difference caused by an extra minute of developing.

Actually, this is making me wonder about my testing regimen. Since I'm gonna use sheet film, it affords me some flexibility in testing exposures. Perhaps I'll pick a set 1st dev time, and take 4 exposures over a wide range of ISO's. I'll be shooting TXP320, so maybe I'll shoot a "test scene" at 320, 250, 125 and 64. Develop at ___ minutes, process as you would and see the results. Then, in the same sitting, with duplicate exposures, develop for X minutes longer. 8 exposures and an evening could tell one a lot about RP.

holmburgers said:

Steve, I've never used Rodinal, so you're safe from me at least!

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My use of Rodinal was because a) I had some!, b) it's mentioned by Existing Light on his website and c) when I used it conventionally it seemed to produce contrasty negatives, which seemed desirable to avoid a muddy appearance when reversal processed. On projection last night, the results were a little disappointing compared to holding them up to the light and some serious additional exposure and/or development is certainly required. With the technique described, I think it could be quite a challenge to get anywhere near box speed. Good luck!
Steve

Is a K-dichromate/sulfuric acid bleach reusable? It seems like a volatile mixture, does it keep?

Also, how about a sodium-sulfite clearing bath?

I've got all my chems ready, powders weighed out, and 6 sheets to process... just tying up the loose ends!