Another thing is printing that image on VC paper optically. I guess you realize that you would need a complex masking in the enlarging or an special development of film, or both.
Autophen (Ilford's commercial PQ variant of ID-II/D76) could be replenished just by topping up add-infinitum,
Developers like D94/D94a are for reversal processing and need a higher level of Bromide because of the Thiocyanate or DTOD both Silver solvents.
developers switched to Phenidone
Kodak D-94A (formula: Metol 0.6g, Sodium Sulfite 60g, HQ 20g, NaBr 7g, DTOD 0.42g, NaOH 20g) is a completely different animal compared to D-96 or D-76. It is a superactive high contrast developer well suited for reversal processing, but nothing one would want for B&W negative development. Note: you won't find a "normal" B&W negative developer with 5+ g/l bromide in its working solution. A switch from MQ to PQ type developer, on the other side, would likely lead to very similar results, maybe 1/3 - 1/2 more speed, and greatly reduced sensitivity to bromide.D-96 is formulated with 0.4gr/L of KBr, while D-94A (Metol Hidroquinone also) is formulated with 7gr/L of KBr, 17 times more. With D-94A even the replenisishment contains some KBr because the bleed removes too much of it.
With the waste regulations as described, and 750 gallons of photographic liquid around, I would have thought, that silver recovery is a nobrainer. Which puts the limitation of fixer capacity squarely back into the bromide/iodide corner. Are the hazmat regulations less strict with (potentially silver ion containing) fixer than with developer?Of course, but life limitation of the fixer comes from silver content, when silver is at 1gr/L (archive) or 2gr/L (commercial) bromide still it's not a problem, so first you have to do to extent chem usage is removing silver. I geuss that we all understand that.
Reduction potential rises with developer pH, but only up to a point. The real reason, why D-94 needs such high levels of bromide, is the DTOD as pointed out by Ian. It's the combination of high HQ, high pH and relatively high DTOD content, which makes D-94 a very unusual developer, and one quite unsuited for normal B&W development.IOK, but D94 is a very, very high Br content developer that it also has Metol in the formulation, so superadditivity remains, and we are talking about a high-energy developer, so in that ultra high KBr formulation Metol works.
in D-94 pH is near 12.8, in D-96 pH is 8.6
Probably this is related to when Metol works with high KBr or not, given the REDOX of Metol.
Ian, thanks for the explanation.
It can be pointed that Xtol is also replenished up add-infinitum, as overflows provide also a high enough evacuation rate of by-products.
OK, but D94 is a very, very high Br content developer that it also has Metol in the formulation, so superadditivity remains, and we are talking about a high-energy developer, so in that ultra high KBr formulation Metol works.
in D-94 pH is near 12.8, in D-96 pH is 8.6
Probably this is related to when Metol works with high KBr or not, given the REDOX of Metol.
Kodak D-94A (formula: Metol 0.6g, Sodium Sulfite 60g, HQ 20g, NaBr 7g, DTOD 0.42g, NaOH 20g) is a completely different animal compared to D-96 or D-76. It is a superactive high contrast developer well suited for reversal processing, but nothing one would want for B&W negative development. Note: you won't find a "normal" B&W negative developer with 5+ g/l bromide in its working solution. A switch from MQ to PQ type developer, on the other side, would likely lead to very similar results, maybe 1/3 - 1/2 more speed, and greatly reduced sensitivity to bromide.
PS: I am realistic enough to accept, that your management would NEVER support a switch from established MQ to experimental PQ formula, so my argument may be moot from the onset.
With the waste regulations as described, and 750 gallons of photographic liquid around, I would have thought, that silver recovery is a nobrainer. Which puts the limitation of fixer capacity squarely back into the bromide/iodide corner. Are the hazmat regulations less strict with (potentially silver ion containing) fixer than with developer?
Go and look at Michael Kenna's night work.
Your approach is giving you difficulty because you are likely underexposing and by the sounds of it underprocessing too.
It's not a Fine grain still film developer so is irrelevant here when discussing D76.
Reduction potential rises with developer pH, but only up to a point. The real reason, why D-94 needs such high levels of bromide, is the DTOD as pointed out by Ian. It's the combination of high HQ, high pH and relatively high DTOD content, which makes D-94 a very unusual developer, and one quite unsuited for normal B&W development.
It's the DTOD which puts the Metol into gear at this high pH in D-94A, and ideally without much of a speed loss. You can bring up Kodak D-82 as a working developer with Metol, high pH and loads of KBr, but that's also a developer you don't want to get anywhere near your normally exposed film. Note, that D-82 has an order of magnitude more Metol in its formula compared to D-94(A). The next stage (even more bromide, even higher pH) would be D-8, which doesn't even bother with Metol any longer, and I wonder, whether the bromide starts acting as solvent at 30 g/l.Of course, D-94 is for reversal as you pointed, it was just to show that Metol can also be in a formulation with ultra High KBr, if the formulation has the suitable strong pH.
So you are right in that Br interferes with Metol, just pointing that it also depends on pH and may be other things.
It would be interesting to know how Metol sensitiveness to Br changes with pH.
You complain about difficulties, yet all the relevant parameters are cast in stone. This makes your job both very easy, and very unstableAbsolutely no chance of a developer change.
It's the DTOD which puts the Metol into gear at this high pH in D-94A, and ideally without much of a speed loss. You can bring up Kodak D-82 as a working developer with Metol, high pH and loads of KBr, but that's also a developer you don't want to get anywhere near your normally exposed film. Note, that D-82 has an order of magnitude more Metol in its formula compared to D-94(A). The next stage (even more bromide, even higher pH) would be D-8, which doesn't even bother with Metol any longer, and I wonder, whether the bromide starts acting as solvent at 30 g/l.
This is: Exposing for the shadows to get the right detail, developing for normal contrast... but selectively compressing highlights in the development to make them printable. What you would do with an HLM done in the development, for a similar effect.
There are 14g Metol working against these 8+ grams of bromide ... and Metol loves to stick to silver ....It looks Br is bad for Metol in the usual pH conditions, as you pointed, but we have those caustic exceptions for insane high energy.
Thank you for grasping what management cannot; they insist that "something must be done, but we can't touch a thing."You complain about difficulties, yet all the relevant parameters are cast in stone. This makes your job both very easy, and very unstable
You don't need to compress the highlights or make a mask with that kind of negative if you know your way around selective fogging.
If you've ever had to try to get good separation back into over compressed highlights, you'll understand why the less you compress them the better.
Not sure how/why the use of D76 used today is different than it's original purpose. The 1st edition of the Leica Manual by Morgan & Lester published 1935 gives D76 as one the few developers for 35mm film. Which only makes sense since 35mm film used in still cameras was motion picture film rolled into cassettes.It's often forgotten that the way D76 is used today is often quite different to it's original origins as a replenished D&P and motion picture developer. It was never designed for amateur use diluted at 1+1 or 1+3.
Not sure how/why the use of D76 used today is different than it's original purpose. The 1st edition of the Leica Manual by Morgan & Lester published 1935 gives D76 as one the few developers for 35mm film. Which only makes sense since 35mm film used in still cameras was motion picture film rolled into cassettes.
I bought packaged D76 for years (still do once in awhile), I also roll mine own. I see no difference in the developed negatives. D76 is a rather simple formula so it's difficult to see where it could be changed to much in a package form.
It also differs because the early motion picture film was designed to be printed on to projectable film, not paper, so was designed for a different contrast than film designed for paper prints.
The film industry would have been more advanced in terms of meters, but large not very portable.
About half-way through the 2nd Edition of "The Film Developing Cookbook" by Bill Troop and Steve Anchell and am really learning a lot.
The section on D-76 kinda stopped me dead in my tracks.
I never knew there were so many variants and that the fresh stuff I mixed was different enough from Kodak's mix to have a real impact on image quality.
So if I am reading this right, Kodak added their "supplements" to prepackaged D-76 to overcome the tendency to rise in PH over time when stored in powdered form and "activate the Hydroquinone", which was otherwise inactive.
Huh?
Why have HQ at all in the formula if it is not "activated".
Did they mean enhance the effect of HQ?
What am I missing?
Well I think (know) that by the early 30's Europeans photographers and particularly Germans were evolving new ways of working epitomised by Hans Windisch in "Die Neu Foto Schule", and also Leica publications.
This involved changing the way negatives were over exposed and developed to much higher densities than we do today, by cutting exposures and development they achieved finer grain and better sharpness with 35mm films. There was still a degree of uncertainty with exposures and a stop safety factor was added to the film speeds, but meters ere becoming available, Gossen advertised in Die Neu Foto Schule. The film industry would have been more advanced in terms of meters, but large not very portable.
Print film emulsions wouldn't have been much different to printing papers.
Ian
If you refer to this MSDS here, then there is a mention of 0.1 - 1% Boric Anhydrid in the materials list, a compound which is not part of the original formula. Interestingly, this compound is not listed in the working solution ingredient list, which puts it below 0.1% of the working solution, which means below 1g/l.Kodak's own MSDS data indicates the increased buffering compared to the original published formula and there's no disputing that.
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