The Ins and Outs of D-76 -- (The Film Developing Cookbook)

[Ian Grant]

This seems like a lot of words that are very delicately trying to sidestep a lack of experience and properly rigorous testing. I can also see your methodology producing a lot of horrible to print negatives, requiring a high grade to set the shadows sensibly, with some painfully tricky dodging - and that's before dealing with getting the highlights where they need to go. Masking should not need to be routine - especially with the sort of thing you propose photographing.

By excessive use of N-, all you are doing is making your life harder than it needs to be. All you want is to straighten out the film curve just enough to get as much of the highlights as needed on a decently linear portion of the curve - knowing that you also need to still be able to print the shadows hard enough that they still look 'right', thus too much underdevelopment is equally to be avoided.

And if you're using an Epson flatbed as a comparator, all you're doing is comparing its sensor noise/ aliasing response. Not much use as an analytical tool. Better to make a few prints in the darkroom and see if by slightly tweaking the overall contrast in printing you can match the results of the differences in negative processing. I can think of many negatives which after persuading on to paper a grade or more harder than 'correct' look dramatically crisper and sharper - all without wasted efforts at the developing stage.

I'm rather inclined to agree with you. The internet has allowed a lot of hype about stand development and minimal agitation, that's not to say there may not be uses but it's not a coincidence that no well known photographers use these techniques and it seems to be only amateurs experimenting. (The only exception is Steve Sherman).

Ian

 

[138S]

(The only exception is Steve Sherman).

In particular, Steve sent me scans of a side by side of stand vs regular. I made for him the analytics of the microcontrast of the textures, comparing the tonal range of the textures to the full range of the scene in both situations, negatives were of matching contrast. The histograms I made for him are briefly seen in one of his videos.

I'm pretty sure about two things, first is that the material he sent me was totally fair and had no manipulation, second is that EMA (and other) has a very remarcable impact in microcontrast, if properly done.

In fact everybody can check that, quite easy, just one has to make a regular vs stand side by side, matching contrast, then we scan each negative. In Ps, if we select a crop and later we press Ctrl+M the we see the histogram of the crop, then we see the tonal range dispersion of the crop, if we select a crop of a texture we see the tonal range of the texture. The wider the peak (compared to scene range) the higher the microcontrast, I guess this is easy to understand.

Since I made that analytics (2 years ago) I've been playing with different agitations, and I guess that I learned the effects, before that I was a little skeptical.

It has to be remarked that EMA does not end necessarily in an overcompressed negative, we can develop for normal contrast, what EMA compresses is extreme highlights making its texture printable, a sort of effect we may also obtain with AZO type paper (Lupex, Lodima) , or by using pyro on VC paper, as the strong yellow stain of the highlights selectively prints highlights with a lower contrast grade.

... but what EMA also does, without any kind of doubt, is increasing microcontrast by a very perceptible amount. IMO what Steve says is totally fair. Another thing is if one wants that effect or not, but the effect is there and it's real.

 

[Mr Bill]

All of this is very helpful, as we run about 750 gallons of D96 in our continuous negative processor and are constantly "chasing the dragon" in fighting bromide build-up, even with what should be adequate replenishment. However we are also constantly being pressured to lower our waste stream, so it is a delicate balance. I am hoping to better understand the mechanisms to assist in this process...

Hi, look, there is no magic in this. If the bromide ion is exceeding the spec values then what "should be adequate replenishment" is pretty clearly not enough. With the possible exception that you have excessive evaporation. The bromide increase in developer (processing tank) is a direct result of development producing metallic silver (from a silver bromide based photo material). To keep it at some spec level you essentially have to dilute it down with replenisher. I'm not experienced with your D96 system, but I can't imagine that it's any different (I've worked mainly in the color neg/printing systems, dating from EP2 paper, which WAS silver-bromide based). If your replenisher formulation contains bromide then you might consider changing the formula, assuming that you have enough analytic facilities to make sure that the processing tank solutions stay within spec. Otherwise, you pretty much have to increase the replenishment rate. With respect to possibly excessive evaporation (relative to replenishment volume) you can check the "specific gravity" of the tank solution; you float a hydrometer (with the appropriate measuring range and precision) in a clear glass cylinder, read it and compare to spec. If evaporation is significant then the specific gravity will go high.

Regarding the pressure to lower your waste stream, I can't imagine that increasing the developer replenishment rate is gonna be a huge factor in this. You're not saying that "they" (I assume your local POTW) are having a problem with bromide ion, are you? (It should be spec'd on your sewer permit, assuming a POTW, if it is.)

 

[Kino]

Hi, look, there is no magic in this. If the bromide ion is exceeding the spec values then what "should be adequate replenishment" is pretty clearly not enough. With the possible exception that you have excessive evaporation. The bromide increase in developer (processing tank) is a direct result of development producing metallic silver (from a silver bromide based photo material). To keep it at some spec level you essentially have to dilute it down with replenisher. I'm not experienced with your D96 system, but I can't imagine that it's any different (I've worked mainly in the color neg/printing systems, dating from EP2 paper, which WAS silver-bromide based). If your replenisher formulation contains bromide then you might consider changing the formula, assuming that you have enough analytic facilities to make sure that the processing tank solutions stay within spec. Otherwise, you pretty much have to increase the replenishment rate. With respect to possibly excessive evaporation (relative to replenishment volume) you can check the "specific gravity" of the tank solution; you float a hydrometer (with the appropriate measuring range and precision) in a clear glass cylinder, read it and compare to spec. If evaporation is significant then the specific gravity will go high.

Regarding the pressure to lower your waste stream, I can't imagine that increasing the developer replenishment rate is gonna be a huge factor in this. You're not saying that "they" (I assume your local POTW) are having a problem with bromide ion, are you? (It should be spec'd on your sewer permit, assuming a POTW, if it is.)

With all due respect, you don't have to deal with our Safety Office, the Architect of the Capitol, The Virgina DEQ and our management. Yeah, it's all been worked out in the last 100 years, but tell that to a bureaucrat

According to them, we are just short of handling spent plutonium.

When all waste water has to trucked away as "hazardous waste" (there is NO drain here) and ANY change to replenishment rates have to be approved by 3 Federal Agencies, you don't have a simple route to address issues.

It's a fact of life; it isn't going to change and I have to deal with it.

 

[138S]

as we run about 750 gallons of D96 in our continuous negative processor and are constantly "chasing the dragon" in fighting bromide build-up, even with what should be adequate replenishment

Bromide is removed from the replenished tank by the overflow waste it's produced when the replenishment is done, the waste has bromide and the replenisher added not, so equilibrium is reached when the waste (after replenishment) has as much bomide as the "average" film has generated.

What tells if your replenishment rate is right is Br ion concentration, so if Br shifts from specs then replenishment is not adecuate (suposing evaporation is compensated). I recall all that from the times I had serviced some RX medical processors.

"In average" 20% to 40% of the silver in the negatives is developed, well this is an ample range, if negatives are denser more bromide is generated than if negatives are thinner, a roll may generate x4 more bromide than the next one...

On the paper, replenishment can be automaticly adjusted, I'd try to use a "bromide ion sensor" probe (https://www.google.com/search?q=Bro....69i57j69i65.651j0j4&sourceid=chrome&ie=UTF-8 , about $800) to measure bromide, then I'd adjust replenisment rate to lower than normal rate, but when probe says Br is high enough then a control device would activate a Delay-Off timer holding open the replenishment electrovalve (or motor) for an extended period which would double the repenisment dose every time a dose is delivered, until the Br ion is under specs. Of course that project would require an effort for a practical fielding, the single critical matter is accuracy of the Br "Ion-selective electrode" probe in the fielded system, the hacking may be straight for the right technician.

Said simple, a way to automate replenishment dose would be adjusting replenishment to a low dose, and hacking the valve/motor that makes the dose to double that dose if a Br probe says Br is higher than a certain level.

 

[john_s]

......... If your replenisher formulation contains bromide then you might consider changing the formula, .....

Surely there would be no bromide in a replenisher.

 

[138S]

Surely there would be no bromide in a replenisher.

Yes... the strategy is that starter developer has bromide and the replenisher not, so replenishment generates an overflow that removes the same bromide that development generated, this keeps the bromide in the right level.

In theory a replenisher may contain bromide but it always should be in a lower concentration than starter, we need a difference because the overflow+replenishment balance has to remove the same average amount of bromide than development generated, but in practice I guess the chem can be designed to make replenisher free of bromide.

 

[Rudeofus]

If bromide buildup is a major concern, then maybe a switch to a Phenidone based developer might be worth looking at ? Also allow me the question: if waste created through developer replenishment is such an issue, wouldn't there be much more issue with fixer replenishment?

 

[138S]

If bromide buildup is a major concern, then maybe a switch to a Phenidone based developer might be worth looking at ? Also allow me the question: if waste created through developer replenishment is such an issue, wouldn't there be much more issue with fixer replenishment?

Phenidone, HQ, metol or Caffenol C all generate exactly the same Bromide, bromide is proportional to the developed silver.

only staining (pyro) developers generate less bromide, as a share of the density is obtained from the stain, thus developing less silver for the same density.

be much more issue with fixer replenishment?

In general fixer is not usually discarted because it is eahausted, but because silver levels in the liquid are beyond what can be tolerated (around 2gr/L, IIRC) For fixer the solution is a silver recovering device that continously removes silver from the soup, this also was lucrative for a big lab, paying for a share of the chem cost.

Current price of silver is $500 per kg. so around $1 value per 1 L of used fixer, I guess the lab sells it cheaper because it has to be processed.

 

[Lachlan Young]

In particular, Steve sent me scans of a side by side of stand vs regular. I made for him the analytics of the microcontrast of the textures, comparing the tonal range of the textures to the full range of the scene in both situations, negatives were of matching contrast. The histograms I made for him are briefly seen in one of his videos.

I'm pretty sure about two things, first is that the material he sent me was totally fair and had no manipulation, second is that EMA (and other) has a very remarcable impact in microcontrast, if properly done.

In fact everybody can check that, quite easy, just one has to make a regular vs stand side by side, matching contrast, then we scan each negative. In Ps, if we select a crop and later we press Ctrl+M the we see the histogram of the crop, then we see the tonal range dispersion of the crop, if we select a crop of a texture we see the tonal range of the texture. The wider the peak (compared to scene range) the higher the microcontrast, I guess this is easy to understand.

Since I made that analytics (2 years ago) I've been playing with different agitations, and I guess that I learned the effects, before that I was a little skeptical.

It has to be remarked that EMA does not end necessarily in an overcompressed negative, we can develop for normal contrast, what EMA compresses is extreme highlights making its texture printable, a sort of effect we may also obtain with AZO type paper (Lupex, Lodima) , or by using pyro on VC paper, as the strong yellow stain of the highlights selectively prints highlights with a lower contrast grade.

... but what EMA also does, without any kind of doubt, is increasing microcontrast by a very perceptible amount. IMO what Steve says is totally fair. Another thing is if one wants that effect or not, but the effect is there and it's real.

Let's start at the top: rather than getting defensive about your work and firing off PM's, you need to disclose what equipment you used & the overall procedures you utilised - if your work is to stand up scientifically, it must be repeatable and applicable.

Which brings me to my next question: do you have evidence that disproves the MTF results (not 1951 resolution charts) of Robert J. Simcoe where he characterises the V7xx (and by extension, the V8xx) Epsons as 'of limited value for scientific imaging of feature sizes below about 50μm'? My own experience is close enough to Simcoe's results to not dispute them - and I would suggest that as a means of grain characterisation, let alone for analysis of edge sharpness and microcontrast, those machines are an extremely poor choice. If your testing was done on this basis, it will suffer sufficiently serious distortion of results such that its usefulness must be disputed.

Next, have you tested to see if the overall contrast scale of the negatives can be matched by conventional processing means? If not, this is a critical oversight - especially because greater microcontrast has as much to do with the subsequent grade the image is printed on as anything at the film processing stage. Was this done using certified, calibrated equipment? Most critically of all: can an equivalent result be achieved using a continuously agitated negative - and could it be matched using D-76? If Richard J. Henry's microdensitometry results etc for agitation are accurate, then it should potentially be possible to essentially make indistinguishable negatives from different agitation patterns, when development times are corrected to match contrasts. Full stand development is a bad idea - and there's plenty of evidence of this. What I have found through both proper high resolution scanning and extensive darkroom printing is that Henry's characterisation of the differences between ID-11 and Rodinal as essentially one of slightly coarser granularity on Rodinal developed negatives and all other observable characteristics being largely equal between the developers is largely true in my experience - and certainly not divergent enough to test further (Rodinal negatives do seem to produce divergent granularity on lower resolution scans, again, not had any need/ urge to investigate further). This coarser overall granularity may in very small enlargements (4-5x perhaps) give a sense of higher sharpness - much as a lower resolving but very high contrast lens may appear 'sharper' than a very high resolving optic with lower overall contrast in smaller prints. The same principles apply to most of the staining developers - indeed, one comment I've heard from multiple people over the years, all working quite independently of each other is that the Phenidone/ Catechol staining developers are 'no sharper than dilute Perceptol!' - though the extra shadow speed from the Phenidone and contrast alteration of the stain may be useful for some people.

I want to make it clear that the reason I'm questioning your methodology is to ensure that your results have actual worth and aren't more stand-development noise.

 

[138S]

Let's start at the top: rather than getting defensive about your work and firing off PM's,

Lachlan, if you are to fire personal considerations I'm to debate nothing with you, to me this wording is offensive:

"this seems like a lot of words that are very delicately trying to sidestep a lack of experience and properly rigorous testing"

Full stand development is a bad idea - and there's plenty of evidence of this.

YMMV. It depends on your skills to perform an stand for the result you want.

I want to make it clear that the reason I'm questioning your methodology is to ensure that your results have actual worth and aren't more stand-development noise.

Lachlan, don't belive in what I say, make your own test with, for example, the Steve's recipe with FP4 and HD.

Do you know how to calibrate film, isn't it ? Do it, from speed point to H log = +3, you'll see the shouldering of the curve vs rotary.

For the microcontrast probably you are also able to check it, do it.

From this you will now what is stand noise and what is sensitometric facts. Just do it.

Me, I'm proficient digital image processing, I've no doubt about the measurements I made.

 

[Mr Bill]

I see I've been missing out on all the fun in this thread...

Surely there would be no bromide in a replenisher.

Try telling that to C-41 developer replenisher (apologies for sidetracking away from the original topic). Of course you should want some evidence that it contains a form of bromide. All that I'm free to give you is indirect - if you look at Kodak's Z-131 (I think) processing manual, under replenishment rates, you'll see that there is a regular replenisher and an LORR replenisher. The LORR uses about half the replenishment rate. If you accept the idea that both systems operate with the same bromide concentration in the processing tank solution (which they do) the obvious conclusion is that the replenisher with the higher rate must contain some form of bromide.

If that's not strong enough evidence that some developer replenishers DO contain bromide, look for Kodak publication C-111, the formulas for (obsolete) process E-4. You should see that the first developer replenisher contains sodium bromide.

 

[Mr Bill]

What tells if your replenishment rate is right is Br ion concentration, so if Br shifts from specs then replenishment is not adecuate (suposing evaporation is compensated).

Well, not completely. A processor should really live by processed test strips, aka control strips, that are "read" to test for the "correct" level of processing. In an ideal world the bromide ion concentration would track perfectly with it (at least in the process being discussed), but there are things that could damage the developing agents, such as oxidation, or perhaps there could be mixing errors. In these cases the development could be off even though bromide levels are correct. (Bromide would seem to indicate a "correct" average amount of silver developed, but perhaps the contrast is wrong, etc.)

I'd try to use a "bromide ion sensor" probe

I'm curious about these; do you have actual experience with their use in photo processing? We used to occasionally (20 plus years ago) use selective-ion electrodes to look at bromide and iodide concentrations in developer. It was a somewhat finicky process, recording readings throughout a titration; in some cases there was not a clear break between species; the standard "fix" was to add a known amount of whatever in order to separate the inflection points. (I think the basic method is described in the Kodak H-24 process manual)

 

[Lachlan Young]

I'm rather inclined to agree with you. The internet has allowed a lot of hype about stand development and minimal agitation, that's not to say there may not be uses but it's not a coincidence that no well known photographers use these techniques and it seems to be only amateurs experimenting. (The only exception is Steve Sherman).

Ian

I think it has a lot to do with a lack of printing experience/ ability on the various claimants parts - and if plotted against time/ acquisition of real ability, it would probably mirror the charts that depict the Dunning Kruger effect. Its use as a panacea is also interesting to me - I first encountered extended agitation intervals as a means to make longer scale negatives! There's also a bit of the sense that its various proponents think they've rediscovered sliced bread because they've realised you could potentially cut bread with a laser...

I also suspect that if someone tried to improve D-76 or Microphen for optimal sharpness and granularity across all formats with the aid of all the analytical kit the manufacturers have, they'd likely still end up with Xtol or DDX - especially if avoiding toxic ingredients was a serious concern.

 

[138S]

Well, not completely. A processor should really live by processed test strips, aka control strips, that are "read" to test for the "correct" level of processing.

Of course a replenishment have several main parameters: Oxydation, evaporation and replenishment rate.

What I say is that IF evaporation is compensated then the Bromide ion concentration establishes if the replenishmet rate is correct. Br is a restrainer an its level is critical.

Having Br level in specs is what says if the replenishment rate is the good one. Have you a doubt about that?

Of course oxydation and evaporation also require additional corrective mesures, but the replenishment rate is established for stable Br ion.

I'm curious about these; do you have actual experience with their use in photo processing? We used to occasionally (20 plus years ago) use selective-ion electrodes

No experience selective-ion for photo processing.

A (good) friend of me uses those probes for industrial control, he is chief electronics designer of a company manufacturing instrumentation for process control, I've been playing with him with those toys, often we collaborate in some projects.

Those probes have evolved a lot over time, what I know is that today many probes deliver accurate Br readings in a pH 12 environment, so I judged they can be used for realtime Br control in a replenishing system.

It should be checked if they work well inside developer, what happens with dirt on it... it was just an idea... measuring how bromide is to adjust rep dose. Where I've no doubt is in how I'd implement the overdose, a delay-off timer for the doser when Br is high, this share is for arduino kids

 

[138S]

they'd likely still end up with Xtol or DDX - especially if avoiding toxic ingredients was a serious concern.

I also prefer Xtol...

Steve Sherman's proposition HD+EMA has two separate benefical effects for printing highlights.

First effect is the mentioned highlight compression from EMA, while making a normal contrast negative that will print mids well in grade 2... extreme highlights reduce its density by perhaps 0.5D from shouldering.

Second effect it's related to stain effect with VC paper, as the extreme highlights have an strong stain it locally shifts contrast to a lower grade, also increasing compression selectively in the highlights.

The two cumulative effects allow to produce this kind of work (below) in a pure optic workflow, without masking, see how there is texture inside the windows, the real print has to be great.

 

[Mr Bill]

Having Br level in specs is what says if the replenishment rate is the good one. Have you a doubt about that?

Sure, I DO have a doubt. In the perfect world, yes, the bromide ion concentration is an accurate indicator of the correct replenishment rate.

But for a hypothetical problem, let's say that you have a mix error resulting in too high a pH value. And let's say that this gives higher contrast than we were looking for, even with the correct specified bromide concentration. It might be, that to correct the actual processing resulting to the correct aim value, that the bromide concentration has to be slightly raised. Note that I say a mix "error," but it could be a result of slightly off-spec chemicals adding up in one direction.

It occurs to me that we might be looking at different levels of "tightness of control." My background is largely from high-volume pro-level portrait lab work, where we relied on a processing machine staying very consistent from day to day. On the other side of the coin you have (or at least used to) one-hour labs intended for amateur processing. These machines could bounce all over the place, control-wise, and hardly anyone would be able to tell the difference. (My employer, at one time, also owned the largest chain of one-hour labs in the US, so I have some familiarity with this sort of thing.)

 

[138S]

Sure, I DO have a doubt. In the perfect world, yes, the bromide ion concentration is an accurate indicator of the correct replenishment rate.

But for a hypothetical problem, let's say that you have a mix error resulting in too high a pH value. And let's say that this gives higher contrast than we were looking for, even with the correct specified bromide concentration. It might be, that to correct the actual processing resulting to the correct aim value, that the bromide concentration has to be slightly raised. Note that I say a mix "error," but it could be a result of slightly off-spec chemicals adding up in one direction.

It occurs to me that we might be looking at different levels of "tightness of control." My background is largely from high-volume pro-level portrait lab work, where we relied on a processing machine staying very consistent from day to day. On the other side of the coin you have (or at least used to) one-hour labs intended for amateur processing. These machines could bounce all over the place, control-wise, and hardly anyone would be able to tell the difference. (My employer, at one time, also owned the largest chain of one-hour labs in the US, so I have some familiarity with this sort of thing.)

If you want to keep the bromide ion in the specified level you have no other choice than adjusting the dose for it and correcting the other flaws in a diferent way.

Of course you may also overlook Br level an simply adjusting dose for the same result, but a good policy may be correcting each parameter individually.

 

[Kino]

Bromide is removed from the replenished tank by the overflow waste it's produced when the replenishment is done, the waste has bromide and the replenisher added not, so equilibrium is reached when the waste (after replenishment) has as much bomide as the "average" film has generated.

What tells if your replenishment rate is right is Br ion concentration, so if Br shifts from specs then replenishment is not adecuate (suposing evaporation is compensated). I recall all that from the times I had serviced some RX medical processors.

"In average" 20% to 40% of the silver in the negatives is developed, well this is an ample range, if negatives are denser more bromide is generated than if negatives are thinner, a roll may generate x4 more bromide than the next one...

On the paper, replenishment can be automaticly adjusted, I'd try to use a "bromide ion sensor" probe (https://www.google.com/search?q=Bro....69i57j69i65.651j0j4&sourceid=chrome&ie=UTF-8 , about $800) to measure bromide, then I'd adjust replenisment rate to lower than normal rate, but when probe says Br is high enough then a control device would activate a Delay-Off timer holding open the replenishment electrovalve (or motor) for an extended period which would double the repenisment dose every time a dose is delivered, until the Br ion is under specs. Of course that project would require an effort for a practical fielding, the single critical matter is accuracy of the Br "Ion-selective electrode" probe in the fielded system, the hacking may be straight for the right technician.

Said simple, a way to automate replenishment dose would be adjusting replenishment to a low dose, and hacking the valve/motor that makes the dose to double that dose if a Br probe says Br is higher than a certain level.

Thank you; that's very good advice that I wish I could take and implement, but it simply cannot happen with the management, budgetary and safety regulations in place at our facility.

My mind boggles at what it would take to convey just how divorced from good practices and common "lab sense" our work environment has devolved.

If you ever watched "30 Rock" when the Alex Baldwin character quits and takes a government job, you can take that, remove the humor and multiply it by 20 to arrive at the insanity.

We can't change formulas or replenishment rates, all our wash water is trucked-off as hazardous waste, our lab was shut-down for 3 months due to traces of selenium in the water (turned out to be naturally occurring in the well water supply - no it wasn't municipal) and we have to get a "burn permit" to operate a soldering iron.

Get this: my supervisor once asked if we could stop a film processor that was developing 10K feet of dupe negative mid-run to "allow a tour that was late to see the machine in operation". I was sorely tempted to just throw the main power switch and let it fog, but...

Yes, my explorations here are pure fantasy; an escape mechanism to imagine "what if"; what if I were working in a rational work environment where I could make sane adjustments, what would they be?

Humor me.

 

[Lachlan Young]

I also prefer Xtol...

Steve Sherman's proposition HD+EMA has two separate benefical effects for printing highlights.

First effect is the mentioned highlight compression from EMA, while making a normal contrast negative that will print mids well in grade 2... extreme highlights reduce its density by perhaps 0.5D from shouldering.

Second effect it's related to stain effect with VC paper, as the extreme highlights have an strong stain it locally shifts contrast to a lower grade, also increasing compression selectively in the highlights.

The two cumulative effects allow to produce this kind of work (below) in a pure optic workflow, without masking, see how there is texture inside the windows, the real print has to be great.

And you don't think that you couldn't make an equivalent image using a normal development regime and an equally big negative? There are picture libraries full of similar images shot on colour transparency - the contrast range is not as great as you might assume.

 

[138S]

There are picture libraries full of similar images

Lachlan, I can make that image with regular development with a single finger, by editing curves in Ps, some clicks with the finger and entire galleries are filled.

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.

You may overlook how well crafted is that particular image but belive me, there is a lot of excellence in it, I say this after a record of personal pitfalls in night photography with pure optic process, sure that you are much better than me in the darkroom printing, but you should realize that this authentic optic print is quite difficult to nail, requiring a refined technique.

 

[138S]

Thank you; that's very good advice that I wish I could take and implement, but it simply cannot happen with the management, budgetary and safety regulations in place at our facility.

My mind boggles at what it would take to convey just how divorced from good practices and common "lab sense" our work environment has devolved.

If you ever watched "30 Rock" when the Alex Baldwin character quits and takes a government job, you can take that, remove the humor and multiply it by 20 to arrive at the insanity.

We can't change formulas or replenishment rates, all our wash water is trucked-off as hazardous waste, our lab was shut-down for 3 months due to traces of selenium in the water (turned out to be naturally occurring in the well water supply - no it wasn't municipal) and we have to get a "burn permit" to operate a soldering iron.

Get this: my supervisor once asked if we could stop a film processor that was developing 10K feet of dupe negative mid-run to "allow a tour that was late to see the machine in operation". I was sorely tempted to just throw the main power switch and let it fog, but...

Yes, my explorations here are pure fantasy; an escape mechanism to imagine "what if"; what if I were working in a rational work environment where I could make sane adjustments, what would they be?

Humor me.

Yes... fighting pollution is necessary, but there is that toll: absurdities in the system. Every time a regulation is issued there is a balance between benefits and absurdities. The better the regulators the lower the absurdities, but no regulation is free from absurdities, I guess.

My view is that a replenishment should aim Br ion stability, but as Mr Bill pointed in practical situations this is debatable, I guess that there are several ways to keep a replenishment in control. Probably it all depends on how much evaporation and oxydation we have and how we are used to overcome the shifts.

Evaporation has the easiest correction: adding water, what still we have to know how much water to add. Bromide is clearly controled by waste. And oxydation may require ph correction and agents concentration monitoring and correction. Well, simple corrections are rep dose and development time or temperature adjustments...

I guess we may priorize having the soup with all components in specs or just compensating more...

all our wash water is trucked-off as hazardous waste

Just speculating, would not be possible evaporating water to accumulate a solid residue ?

Waste water vacuum evaporation is a common solution https://en.wikipedia.org/wiki/Vacuum_evaporation. An accumulation tank would be required for when you dump all the replenishment tank. That tank would also take the continuously produced weight. Then evaporation device can work 7/24 so you require a way smaller device.

Of course this would introduce new problems like managing powders that are less safe...

Just speculating, I don't know is this is an advantage for photo waste, only pointing that I've seen that way in the industry and many times it was a sound solution.

 

[Rudeofus]

Phenidone, HQ, metol or Caffenol C all generate exactly the same Bromide, bromide is proportional to the developed silver.

That was not my point. The point is, that acceptable bromide levels are much higher in a Phenidone based developer vs. a Metol based one.

In general fixer is not usually discarted because it is eahausted, but because silver levels in the liquid are beyond what can be tolerated (around 2gr/L, IIRC) For fixer the solution is a silver recovering device that continously removes silver from the soup, this also was lucrative for a big lab, paying for a share of the chem cost.

You can get the silver out, no problem, but the bromide stays in there no matter what you do. At some point your fixer will be too slow due to this extra bromide. BTW bromide levels grow at roughly the same pace as silver levels in fixer unless you remove the silver.

I was under the assumption, that you already knew all of this. TBH, your points here puzzle me a bit.

 

[138S]

That was not my point. The point is, that acceptable bromide levels are much higher in a Phenidone based developer vs. a Metol based one.

OK, now I understand your point, buit it's not necessary to go to phenidone for a developer with "acceptable bromide levels".

"Bromide levels" is about formulation much more than on the agents alone.

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.

For this reson your points confused me a bit, not understanting what you pointed.

https://www.kodak.com/uploadedfiles..._en_motion_support_processing_h2415_h2415.pdf

The chalenge is ensuring the right level, for a good fog vs image developement balance.

You can get the silver out, no problem, but the bromide stays in there no matter what you do. At some point your fixer will be too slow due to this extra bromide.

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.

 

[Ian Grant]

You're muddling the low Bromide level to suppress base with thwe Bromide level that suppresses Metol action, and that is purely down to the Metol developing agent and less about the overall developer formulation.

Switch from Metol to Penidone and high bromide levels aren't an issue, Autophen (Ilford's commercial PQ variant of ID-II/D76) could be replenished just by topping up add-infinitum, the huge disadvantage of ID-11/D76 was the need to bleed of some developer before replenishing. This applied to colour as well as B&W developers used replenished and it's no coincidence colour developers switched to Phenidone many years ago.

Ilford published research papers in the 1950's one where they describing how they'd measured exhaustion rates and bromide build up, this was part of the evolution of Autophen and it's two different replenishers, one for just topping up the other bleed replenishment (in older process lines). Much of the work was on maintaining the buffering so there were a few variations publish between the initial simple Phenidone substitution (instead of Metol) in ID-11 and the final commercial formula sold as Autophen.

Developers like D94/D94a are for reversal processing and need a higher level of Bromide because of the Thiocyanate or DTOD both Silver solvents. It's not unusual to have a low level of Bromide in a Fine Grain developer that's going to be replenished, there's no Bromide though in D96 replenisher. Agfa 19 which was their version of D76/ID-11 is identical but has Bromde added between 0.5 and 1g per litre essentially this is like adding a starter or some of an older batch to season a developer. Fresh sock is harsh compared to replenished, less shadow detail, grain isn't as fine, not as sharp so labs would season a new batch.

Many companies made D76/ID-11 with their own name, Agfa 19, May & Baker 320, Defender DF6, etc, this was a standard developer used worldwide for cine film processing as well as till film with films made in different locations process need to be consistent

Other slightly different replenishable developer like Agfa 44 (Asco 17), Adox Borax MQ, Defender D4, etc, all use a small amount of Bromide in the developer, typically 0.5g/l.

Ian,