Removing brown tone from reversal processed b&w?

[Steve Roberts]

I'll type up my process into a legible form and post it here, probably after the weekend as I don't have much in the way of email at home.
Best wishes,
Steve

 

[Steve Roberts]

Hi,
As promised, here are the details of the process I've reached so far. I say "so far" because all things are subject to tweaking! To measure the chemicals by weight I use a small digital balance that reads to 0.01g (how accurate it is, I don't know, but if the first d.p. is accurate, that's probably good enough as long as it's consistent. I bought the balance from a jewellery shop for £20. As has been said, local issues such as water characteristics and individual ways of working will have an effect on the end results, but for what it's worth, here goes:

Black and White Reversal Process for Ilford FP4 exposed at 125ASA.
Check List.
Ilford PQ Universal developer
Stop bath
Fixer
Thermometer
Gallon of water at 20 degs C
Potassium Permanganate 0.8g
Sodium Bisulphate 11g
Sodium Metabisulphite 12.5g
Hypo stock solution 20g in 200cc water (equates to 10cc per gram hypo required)
Lamp with 100W bulb

All at 20 degs C until final wash.

1) Pre-soak for 5 mins.

2) Develop Ilford PQ Universal 1 + 5 + 4g/l hypo.
Invert twice each 15 secs for 10 mins.

3) Stop bath 1 min (not in Ilford procedure – see note below)

4) Water wash (Ilford recommended procedure)
Invert 5 times, discard.
Invert 10 times, discard.
Invert 20 times, discard.
Invert 20 times, leave film soaking whilst making up bleach, then discard.

5) Bleach – 11g Sodium Bisulphate dissolved in 400cc water, then add 0.8g Potassium Permanganate – 5 minutes continuous agitation.

6) Water wash (Ilford recommended procedure)
Invert 5 times, discard.
Invert 10 times, discard.
Invert 20 times, discard.
Invert 20 times, leave film soaking whilst making up clearing bath, then discard.

7) Clearing Bath – 12.5g Sodium Metabisulphite dissolved in 400cc water
Invert twice each 15 secs for 2 mins.

8) Water wash (Ilford recommended procedure)
Invert 5 times, discard.
Invert 10 times, discard.
Invert 20 times, discard.
Invert 20 times, discard.
9) Second exposure – underwater in translucent plastic jug, 12” from 100W incandescent lamp, moving constantly and evenly. (Ilford say remove from reel, but I leave film in my translucent white plastic Paterson reel with no problems).

10) Second developer – Ilford PQ Universal 1 + 9, 6mins

11) Stop 1 min

12) Fix

13) Rinse @ 20 degs C then reduce rinse in stages of about 3 degrees to tap water temperature. Wash 20 mins.

14) Dry.

Notes.

a) Hypo is supplied in large crystals, so a larger quantity in a stock solution seemed more accurate. Ilford recommend 12g/litre, which I found excessive, leading to blown light areas and lack of blacks.

b) Ilford recommend that the “time and temperature be closely monitored if consistent results are to be obtained”. Given that, why do they not suggest a stop bath to arrest development? Their application sheet (2003) says that the acid bleach “stops development immediately” ... hmmmm .... only after the 5 mins wash process, though!

c) Bleach – dissolve Sodium Bisulphate first at it doesn’t dissolve readily and once the permanganate has been added you won’t be able to see whether the bisulphate is all in solution. Ilford procedure uses sulphuric acid but this is Existing Light’s recipe. Though some say this softens the emulsion unduly, I haven’t found it to be a problem as I leave film in the reel for 2nd exposure.

d) From completion of bleaching, the process can theoretically be continued with the top of the tank removed though I don’t do this as I prefer to regulate the second exposure later on. Don’t ask me why – I just do!

e) I prefer to make up the bleach and clearing solutions when I get to that part of the process, largely because I don’t have much space. I check and correct the temperature of these as necessary, though I suspect I’m being over-cautious.

f) The translucent white plastic reel allows sufficient transmission/reflection of light, but I suspect that a black Bakelite reel would give rise to unexposed areas.

g) Time – allow about two hours for the whole process, as there are many stages and weights/volumes to measure. However, apart from the first development stage, the rest of the process can be completed in easy time, stopping to make a cup of tea, take a breather from all the inversion agitation, etc. during one of the many washing procedures, as required!

Good luck and I hope to hear how others get on with the process.

Steve

 

[johnielvis]

Similar to bleaching to remove unwanted excess density from highlights, intensification, such as chromium intensifier, can be used to build up dmax eroded from the hypo developer (or from too much post-bleaching with ferricyanide).

 

[johnielvis]

oh, there's other intensifiers out there too. Since people use chromium for bleach, it's a no-brainer to also use it for an intensification step. Too bad you can't get the dichromates--it's really a superior bleach--very stable--and every bit as safe as permanganate, as long as you treat it the same way you do permanganate.

 

[mr.datsun]

Hi,
As promised, here are the details of the process ...

Hypo stock solution 20g in 200cc water (equates to 10cc per gram hypo required)


Steve

Steve,

thanks very much for taking the time to describe your process.

The only thing I'm not clear on is what you are using for hypo (and whether it's anhydrous or not). I understand that hypo is usually Sodium thiosulfate or Ammonium thiosulfate. I use Sodium thiosulfate but my quantity (with Dokumol) is a fraction of what you use. I think the quantity of hypo (or other silver solvent) is the prime factor influencing the image, given any active-enough developer. Developer time doesn't seem to make too much difference (at least with the Dokumol). e.g. 12 mins or 15 mins give very similar results.

I wonder whether those last 20 inversions at rinse stage are necessary?

Out of interest, how long did it take you to get to this stage in your process?

 

[johnielvis]

just out of curiousity--has the brown stain boogeyman been identified yet or is it still a plague?

I had a brown stain problem, but it was cured by a change in diet.

 

[mr.datsun]

just out of curiousity--has the brown stain boogeyman been identified yet or is it still a plague?

I had a brown stain problem, but it was cured by a change in diet.

I've had to put film processing on the back-burner for a while. I will need to try the C41 E6 bleach test but no idea how I can get a small enough amount for a test.

 

[johnielvis]

OH, well, good luck then. Please do report the results. I've had similar stain with dichromate bleach.

 

[Rudeofus]

I've had to put film processing on the back-burner for a while. I will need to try the C41 E6 bleach test but no idea how I can get a small enough amount for a test.

You can possibly get a sample from some minilab near you, or you get one of these C41 or E6 kits. For this experiment it doesn't matter whether you use bleach or BLIX. If you let us know where "The end of the world" is, maybe some other APUG member nearby can give you a sample.

 

[mr.datsun]

You can possibly get a sample from some minilab near you, or you get one of these C41 or E6 kits. For this experiment it doesn't matter whether you use bleach or BLIX. If you let us know where "The end of the world" is, maybe some other APUG member nearby can give you a sample.

Rudeofus. Excellent idea.

I'm in London within a stone's throw of the Arsenal stadium. If anyone could give me a sample it'd be very gratefully received.

 

[Steve Roberts]

What I'm using is the old-fashioned, traditional Sodium thiosulphate. Whether it's anhydrous or not - you've got me there! It's the only type I've ever come across - transparent crystals, elongated with several sides and up to a quarter inch in length, about an eighth diameter. My guess is that it's not anhydrous.

I agree that the amount of hypo is a key factor - too much gives no true blacks and blown highlights, though rating the film at a higher ASA can give usable though low contrast results. When you say that you're using a fraction of the hypo I am perhaps I'm not explaining myself well. I'm dissolving 20g of hypo in 200cc H2O, then using 10cc of this solution per gramme hypo required. At 4g/litre, for my 35mm tank, which requires 300cc of solution to cover one film, I'm using 12cc or effectively 1.2g hypo. How much do you use?

I'm not sure how much the last rinse inversions are necessary, but I guess I'm just erring on the side of caution.

At a rough count-up, I've been through about ten films to get to where I am. Four were with Rodinal as first developer and were at best inconsistent. Then I latched on to the current process, starting with widely varying exposures (and ending up at box speed, as Ilford suggest), then playing with the first development time and hypo added. At one stage everything went to pot and I seemed to be back to square one but identified the problem as a fault with the shutter speeds on my Pentax K2 which, even in manual mode, were pretty much random! That's now away for repair.

This evening I projected some reversal b/w slides to someone else for the first time and the reaction was one of surprise that they could be as effective and were more artistic than similar shots would be with all that distracting colour!

Best wishes,

Steve

 

[Rudeofus]

What I'm using is the old-fashioned, traditional Sodium thiosulphate. Whether it's anhydrous or not - you've got me there! It's the only type I've ever come across - transparent crystals, elongated with several sides and up to a quarter inch in length, about an eighth diameter. My guess is that it's not anhydrous.

You are correct, that's the pentahydrate Na2S2O3 * 5 H2O

 

[mr.datsun]

What I'm using is the old-fashioned, traditional Sodium thiosulphate. Whether it's anhydrous or not - you've got me there! It's the only type I've ever come across - transparent crystals, elongated with several sides and up to a quarter inch in length, about an eighth diameter. My guess is that it's not anhydrous.

I agree that the amount of hypo is a key factor - too much gives no true blacks and blown highlights, though rating the film at a higher ASA can give usable though low contrast results. When you say that you're using a fraction of the hypo I am perhaps I'm not explaining myself well. I'm dissolving 20g of hypo in 200cc H2O, then using 10cc of this solution per gramme hypo required. At 4g/litre, for my 35mm tank, which requires 300cc of solution to cover one film, I'm using 12cc or effectively 1.2g hypo. How much do you use?

Steve - you are explaining yourself well. I understood correctly.

You are using 4g/L hypo.

For Rodinal I'm using around 0.76g/L, for Dokumol I'm using around 2.88g/L

You are using standard Sodium Thiosulphate (as confirmed by Rudeofus) whilst I'm using the anhydrous (which I now realise is the stronger of the two). Anhydrous is meant to be 1.6 times stronger by weight - and that largely explains the difference.

I was interested that Rodinal seemed to require approx. 1/4 the hypo needed with Dokumol when I tried it.

The fact that you have got where you are after 10 films is admirable!

 

[Rudeofus]

I was interested that Rodinal seemed to require approx. 1/4 the hypo needed with Dokumol when I tried it.

Isn't Dokumol a much stronger and much faster developer? That would explain why it needs more solvent for the same (or at least similar) effect.

 

[mr.datsun]

Isn't Dokumol a much stronger and much faster developer? That would explain why it needs more solvent for the same (or at least similar) effect.

I speculated that for a given 1st developer, if less hypo was required to clear all the remaining undeveloped silver halides that prevent clear highlights, then that 1st developer must be converting more halides to silver. More action in the first developer = a lighter final positive image (and hence reduced need for the hypo).

 

[Rudeofus]

There will always be some undevelopable silver halide that needs to be cleaned up by the solvent. The less time this solvent has for doing its job, the stronger it needs to be.

 

[Steve Roberts]

The fact that you have got where you are after 10 films is admirable!

Not really - I did get off to a flying start, thanks to APUG and Ilford!

Steve

 

[mr.datsun]

There will always be some undevelopable silver halide that needs to be cleaned up by the solvent.

In theory could a developer develop the silver halides to max dMax at first run through?

The less time this solvent has for doing its job, the stronger it needs to be.

I see your point, but in my case the R09 was used for 10 minutes and Dokumol for 12 minutes and the R09 needed less hypo.

On a similar theme, will hypo reach an exhaustion point?

 

[Rudeofus]

In theory could a developer develop the silver halides to max dMax at first run through?

If the film area is sufficiently exposed ... and that's key: few scenes will give you that. The characteristic curve goes waaaaaaaaay up.

I see your point, but in my case the R09 was used for 10 minutes and Dokumol for 12 minutes and the R09 needed less hypo.

But how fast did they do most of their work? Is there significant difference between 3 minutes of Dokumol or 12 minutes?

On a similar theme, will hypo reach an exhaustion point?

Most certainly, especially when it is as dilute as it is in reversal developers. Also note that for every Silver ion bound by Thiosulfate/Thiocyanate/whatever a free Halide ion enters the developer. In case of photographic film that means Bromide or Iodide, and both counteract fixer action and development.

 

[johnielvis]

The unexposed silver halides are always present. They are there even after the second development, which is why there is the need for the final fixing step. Some films there is not much and it is not noticeable, but some films it is VERY noticable. The tmax films for example. After a process with non-hypo developers. After first development, bleaching, re-exposure and second development (TWO developments with a LOT of exposure in the re-exposure step) there is still a brown/yellow cast to tmx100 until after the final fixing step. Note that this brown/yellow cast is not developed, reduced, silver, but silver halide that remained undeveloped and was removed by fixing. The same type of cast is not noticable in tri-x professional, which looks the same before and after the final fix.

 

[Jim Taylor]

Also note that for every Silver ion bound by Thiosulfate/Thiocyanate/whatever a free Halide ion enters the developer. In case of photographic film that means Bromide or Iodide, and both counteract fixer action and development.

Rudeofus - this is interesting. So - is there something to be done to quench or otherwise sequester those pesky free-halide ions? Or is it as simple as ensuring there is sufficient 'excess' developer to mitigate this?

 

[Rudeofus]

Rudeofus - this is interesting. So - is there something to be done to quench or otherwise sequester those pesky free-halide ions? Or is it as simple as ensuring there is sufficient 'excess' developer to mitigate this?

Not really, and this will eventually kill every fixer even if you somehow remove/recover the Silver. Note, that not only the solvent liberates halide ions: where do you think they go when you develop silver?

 

[Steve Roberts]

Hi All,
In processing a roll of FP4 reversal last night, I realised that I'd not noted down the second exposure time in my intructions. This is in fact 3 mins per side whilst rotating the reel under water.
I should also have noted that it's a good idea not to wear any clothes that you value, as potassium permanganate leaves a brown stain that is impossible to remove!
Another observation is that I've not found using filters to try to enhance clouds to be very successful, as they tend to give an overall mudiness. A pale yellow helps a little, but I certainly wouldn;t use orange with this film/process. However, the process does seem to render cloluds and dramatic skies very effectively anyway.
Finally, whilst I'd say that the success rate percentage-wise is probably comparable with shooting colour transparencies.
Finally (OK, I've already said that but here goes) as with colour transparency film decent light makes a world of difference to the end result.
Best wishes,
Steve

 

[Rudeofus]

you can eliminate the permanganate stain if you dip your clothes in a metabisulfite solution, much like you do with the clearing bath.

There is a good chance that the Permanganate destroys fabric or dyes when it gets reduced to brown MnO2, which means you can remove the brown stain but still end up with stained clothes. This simple device, on the other side, should take care of all stains

 

[johnielvis]

well...any progress here on finding "the stain"? or does the stain remain?