Acetic acid as stop bath for film?

Photo Engineer said:

[...] I can try my best to present both sides of a story, but if the readers ignore one side or another, then I have accomplished nothing in the end.

I hope that you see my point!

People will do what they want in spite of the fact that the literature says "a water rinse is fine, but a Stop Bath is better". Even Mees, that fine old English expert in R&D and Photography says that! So, ignore my words. They are nothing in the end. You can lead a horse to water but you cannot make them drink.

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That would certainly appear to be the case.

The thing (still) is that you indeed do present both sides of the story, yet are also the one who keeps ignoring one side of it.

You have explained why. Why you think one side is wrought with problems, why the other is not.
Yet asked about those problems, you only cite texts that don't mention those problems, and admit yourself that you have never come across them yourself when you too did the not-so-good-thing.

lensmagic said:

I thought that SOMEONE is supposed to be monitoring these threads to make sure personal attacks do not take place. That someone is failing us. Maybe he or she needs to be replaced. We are in danger of losing the "voice" of the most experienced and best informed member of this forum.

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Personal attacks?
You might want to reconsider that.

We are still discussing the topic.
It's you who is not.

You are the one attacking people because they have something of substance to contribute to a factual discussion.
You are also the one attacking the moderators of this forum.

Oh, and do you know that and noone is infallible?

I use citric acid which i got from someone (5 kilo), but i suspect i get a dry mouth during developing because of some kind of oder i guess?
(i did not change the develop/fix chemicals)
I now bought a bottle of stopbath to see if this is the problem.
So i think this can also happen with the acitic acid.

Lets have some honesty, the facts are all in the references I've posted and Ron - PE's done the same, there's no disputing any of those facts it's how they are interpreted. What I've said all along is that Ron (PE) was repeatedly interpreting those facts to promote one side of the stop bath or rinse, and I've told him in more than one post that those arguments were bullshit, I still think so. However he's re-evaluated some of the references in the more recent posts and changed his stance.

We need to step back to basics which I posted before & linked to again in this thread, here it is yet again:

Summing up

A stop bath is not necessary at all, neither is a water rinse.

Mason states clearly the stage is superfluous to the overall processing of films or papers, and this is also backed up by both Fuji & Kodak who include no rinse or stop in their mechanic film processing data & Ilford who state that there should be no problem in machines with no facility for a stop bath. That's for films and RC papers.

Needs very good agitation to prevent dichroic fogging.

We are talking about using a stop bath or water rinse not leaving the stage out:

1. A stop baths purpose is not the removal of all residual developing agents. There's insufficient time, this will continue during fixing and washing.

2. The purpose of a water rinse or stop bath is the slowing of development, which is more immediate with an acid stop bath

3. The second purpose of a water rinse or stop bath is minimising the carry over of developer into the fixer.

4. The advantage of a stop bath is that the pH of the film has been changed, so helping preserve the buffering of the (acid) fixer, potentially prolonging the fixers life & throughput.

5. Stop bath is detrimental with some soft emulsion films with certain developers, due to pin hole issues.

6. If no stop bath is used there have been reports of Dichroic fogging before an Alkaline/Neutral fixer, but in numerous threads Ron (PE) has always recommended the use of a stop bath before TF-4.

It's up to people to decide which of the manufacturers recommendations they use water rinse or stop bath.

It's also important to remember that modern films are thinner, many have much better hardening of their emulsions, fixers are now predominantly ammonium thiosulphate based “Rapid Fixers”. This means that there's less retention of developer in modern emulsions, also that fixing is more immediate after a stop bath or rinse stage, (with a rapid fixer).

If we relate this to films we can see why the manufacturers still recommend a stop bath or rinse.

With RC papers the issue is large volumes of rinse water would be needed depending on the number of prints processed instead of a much smaller volume of stop bath, machine processing leaves out the step entire in many cases but chemistry is usually removed by passing between rollers so there's little carry over.
With fibre based papers the carry over issue is very much more significant as there's chemistry in the paper base, so a stop bath is imperative. There is still some significant carry over of developer, albeit neutralised, which is one reason why manufacturers recommendations of fixer capacity are fewer prints per litre of fixer when you look at data for FB and then RC papers. That's also borne out in practical experience.

I have no qualms about disagreeing about an issue like this, whether that's with Ron (PE) or anyone else, the facts are plain to see. Possibly only one person Q.G. has actually taken the time to read all the posts in this thread properly.

Ian

Ian Grant said:

Possibly only one person Q.G. has actually taken the time to read all the posts in this thread properly.

Ian

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Well, it is true, I do not always wear a shirt and tie when reading this thread.
But I am quite sure there are thousands who have read this thread in it's entirety.
I, for one, always, read yours and PE's posts.
Properly Yours
Bill

Ian has again abridged Mason's statement which I scanned and posted earlier. I will quote Mason here: "When well-buffered acid fixers are used, this stop bath stage is superfluous, the emulsion being transferred directly into the fixer, but the carryover of the developer by this technique does seriously shorten the life of the fixing bath......" There, in the whole quote you see how the meaning is changed over the what Ian has suggested in his post above. Ian states that he is not referring to leaving out the stop or rinse but the quote from Mason refers exactly to that situation when he uses the word "superfluous" and thus it totally negates Ian's argument.

I have never said that you NEED a stop with TF-4, I have said that you can use one if you wish. I do.

And, a stop will help prevent excessive swell with film products that are prone to greater swell due to lower hardness. That is another reason for using a Stop. The readers may also wish to go back and look at the reasons I posted. I've also stated that I have had yellowing with prints when I omitted the stop, but not film. The literature is not entirely clear on this, and I will assume that this refers mainly to FB papers.

Both Mason and Mees say that a rinse is acceptable for film, but a Stop Bath is better. That has been my position from the start. I prefer a Stop. I recommend a Stop. That has been my position from the start. I have presented both sides of the case, I have stated my preference, I have stated my actual practice, and I have given the reasoning behind it and supporting references.

Do what works for you!

PE

Yes, correct. Swell is minimum at the isoelectric point which for Bone Gelatin is about 4.5. For Pig Gelatin, not common nowdays in photoproducts, the isoelectric point is about 9.5. The curve of swell vs pH for Bone Gelatin has been posted here somewhere.

PE

Very bizarre that someone just reported a purely technical post about swell at the isoelectric point for gelatin as a sign that this thread is "out of hand."

Okay, this thread has had quite a few reported posts on both sides, but it would be really unfortunate to have to close down a thread with much useful technical discussion and debate about a question that many people ask, so I would just ask that all parties, who are very knowledgeable about this question, stick to the facts and avoid personal insults, and would mention that I admire the restraint of those who have not responded to insults in kind.

It's these snide attacks that Ron won't stop.

It's ridiculous to say that highlighting some points is abridging, particularly when the section is from a previous Thread/Post anyway which I made very clear. All commercial B&W fixers are well buffered acid fixers, no mainstream Film manufacturer makes an alkaline fixer for B&W films or even recommends them. So the meaning doesn't change at all, and the whole paragraph is only highlighting something we aren't contemplating doing ourselves but is done commercially.

Then when I mention that Ron recommends using a Stop bath before an alkaline fixer he try's to turn even that against what I've said yet it's something he's said regularly in many posts on fixers.

Ian

Photo Engineer said:

Ian has again abridged Mason's statement which I scanned and posted earlier. I will quote Mason here: "When well-buffered acid fixers are used, this stop bath stage is superfluous, the emulsion being transferred directly into the fixer, but the carryover of the developer by this technique does seriously shorten the life of the fixing bath......" There, in the whole quote you see how the meaning is changed over the what Ian has suggested in his post above. Ian states that he is not referring to leaving out the stop or rinse but the quote from Mason refers exactly to that situation when he uses the word "superfluous" and thus it totally negates Ian's argument.

I have never said that you NEED a stop with TF-4, I have said that you can use one if you wish. I do.

And, a stop will help prevent excessive swell with film products that are prone to greater swell due to lower hardness. That is another reason for using a Stop. The readers may also wish to go back and look at the reasons I posted. I've also stated that I have had yellowing with prints when I omitted the stop, but not film. The literature is not entirely clear on this, and I will assume that this refers mainly to FB papers.

Both Mason and Mees say that a rinse is acceptable for film, but a Stop Bath is better. That has been my position from the start. I prefer a Stop. I recommend a Stop. That has been my position from the start. I have presented both sides of the case, I have stated my preference, I have stated my actual practice, and I have given the reasoning behind it and supporting references.

Do what works for you!

PE

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My post was not an attack. It was a post to present the entire sentence in the correct context. Mason basically said that if you use a Develop then acid Fix sequence with no intervening step, an acid Stop is superfluous, but eventually can cause a problem. Therefore a wash or preferably a Stop should be used between the Developer and the Fix.. Highlighting a sentence by omitting the part that changes or refutes your argument is what I objected to. It runs counter to your desired point so you can leave it out?

Kodak did make alkaline fixes for some processes and had several under development last I knew. Grant Haist describes this in his book and Anchell and Troop enlarge upon it based on Bill Troop's interview of Grant. I have said that you can use a Stop with TF-4 and that I have done so. What is the big deal about that? The Formulary says that a Stop is not recommended as it could lower the pH, but I have stated that TF-4 is so robustly designed that a Stop will not adversely affect the pH under normal use should you wish to use a Stop.

With either a water rinse or a Stop, I have never seen dichroic fog when using TF-4 with either prints or with film. I have seen yellow stain on prints with many fixes when using a water rinse over my years in photography. TF-4 has been on sale for many years with a lot of happy customers regardless of their process sequence.

Kodak C41 Fix is being used now by many B&W photographers and TF-5 is out there with good results as well. These are both near neutral in pH. Ilford makes a near neutral pH Fix as well IIRC. No one seems to have problems with any of these either. IDK what they use between the Developer and the Fix, but I would not be surprised if it turns out to be a mix of rinse and Stop among the various members of the APUG community.

PE

... one more thread on "ignore" ..

Photo Engineer said:

My post was not an attack. It was a post to present the entire sentence in the correct context. Mason basically said that if you use a Develop then acid Fix sequence with no intervening step, an acid Stop is superfluous, but eventually can cause a problem. Therefore a wash or preferably a Stop should be used between the Developer and the Fix.. Highlighting a sentence by omitting the part that changes or refutes your argument is what I objected to. It runs counter to your desired point so you can leave it out?

PE

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My point about Mason saying a stop bath is superflious is extremely valid, particularly as both Kodak & Fuji miss out the step completely in machine processing so obviously agree. So making a comment like you have twice now are just attacks as I said before. The point's there because it indicates that a stop or rinse isn't required for the removal of developer & byproducts carried over in an emulsion, I don't think anything else can be read into it at all.

There's a few posts in threads here on APUG or LFPI where people have said they've had dichroic fogging with an Alkaline fixer and film, so it must happen. However from memory at least one was with Bergger 200 film which was essentially Forte's last reincarnation of pre-WWII Super-X and was a rather thick heavily coated emulsion rather atypical of anything else available today.

I've used a water rinse and then alkali fixer with no issues when processing some films in a borrowed darkroom, a lot may be down to how fresh and also the dilution of the fixer and peoples working techniques.

Ray Rogers also mentioned Agfa saying the same about staing and alkaline fixers n the German text he posted, however those would mainly be Sodium Thiosulphate based fixers where the slower rate of fixing could be far more problematic.

Ian

Ian, as you point out, Kodak and Fuji apparently use a wash step. Mason was referring only to cases where there is NO step between Development and Fixation.

Here is a repost o the entire page. Please look again at the Stop Bath section.

PE

You have a stop-bath built into the bleach.

At one time HCl was recommended as a stop bath, obviously you can't use that but dilute Sulphuric acid acts as a stop bath as well.

Interestingly a book in front of me says Acid stop bath cause excessive swelling of the Gelatin and also reticulation, something both Ron & I would disagree with, it also recommends a running water stop bath with modern films and papers which again we'd both disagree with - stop bath is always recommended with papers.

Ian

And, I agree 100% with Ian on this.

PE

Photo Engineer said:

Ian, as you point out, Kodak and Fuji apparently use a wash step. Mason was referring only to cases where there is NO step between Development and Fixation.

Here is a repost o the entire page. Please look again at the Stop Bath section.

PE

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Ron, I said Kodak & Fuji miss out the rinse/stop, the machines processors go straight from Developer to Fixer, that's for films & RC papers.

In the other thread I posted links to Kodak's Versamat datasheet & the Fuji's equivalent.

Every single point I've made matches exactly what Mason is saying.

Ian

Some early colour reversal processes used a stop bath, there's no reason why you can't either, they also use a pre-hardener for the film, again you can do the same.

It's going to depend on the actual film and the bleach you use later.

Ian

This is the generic description from a search.....

Most Versamat's use developer, then stop, then fix, then water/wash, and finally conditioner. Some variations don't require stop.

Mason does describe the latter condition, but also points out problems that can accrue with that method with some fixes. Mason is not saying that a Stop is superfluous in general but only in the specific case of Develop, Acid Fix and Wash.

I would like to add what I forgot in this post. The recent, no stop process for Versamat, uses a special fix designed to avoid the problems that Mason describes. We obviously do not use those process solutions as they were designed for RA processing at high temperatures.

PE

Photo Engineer said:

Ian, as you point out, Kodak and Fuji apparently use a wash step. Mason was referring only to cases where there is NO step between Development and Fixation.

Here is a repost o the entire page. Please look again at the Stop Bath section.

PE

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I have.
It says that if you don't use an acid stop bath, development will not stop as fast as when you do. And that you can reduce the life span of fixer if you move from developer to fix immediately.
Nowhere does it mention any of the problems you keep telling us we should fear when we use a water rinse instead of a stop bath. Not a single mention of ruined negatives, or even the danger of ruining negatives.

I have said so before: you are presenting a very lopsided view of this matter.
Quite balanced, indeed, when you say that both options work, that both options are endorsed by film manufacturers, that both options are in the literature, that neither option creates problems. So far so good.
But then you give the entire thing a slant by warning us about the dangers of not using an acid stop bath.

What keeps puzzling me is: why?
Why, if you say that both options work, that both options are endorsed by film manufacturers, that both options are in the literature, that neither option creates problems, do we need to fear problems?
Problems (again) that i have never come across, and you too say have never come across? Problems that film manufacturers don't seem to fear either?
And why do you quote texts that don't appear say what you say they would, in support of a view that you, in your balanced reporting, say you don't support?

And re Mees, whom you have referred to, but haven't quoted: i have gone through his "Theory of the photographic process", and nowhere does he even mention stop bath. He doesn't mention a water wash either.
Interestingly, he says:

"Fixing should exert the primary function of dissolving the halide and the secondary one of stopping the development, preventing organic stain and hardening or checking the further swelling of the gelatin."

So Mees, it appears, goes from developer straight into the fixer.

Just as I have said before. Two points of view with one preferred!

"The rinse bath may be either water or an acid stop bath. The acid stop bath is generally preferred for the processing of most types of photographic materials." Mees, "The Theory of the Photographic Process" Revised Edition P709 - 710.

And...

"Although water can be used as a rinse, an acid stop bath is more effective because it can neutralize any alkaline developer remaining in the emulsion layer and rapidly lower the pH to the point where development ceases. This also has the effect of preventing aerial oxidation of the developing agent, which otherwise could form staining products in the gelatin layer." (This also mentions a number of other benefits including reducing swell.) Mees and James, "The Theory of the Photographic Process" Third Edition P397.

And, two editions of the book as well. I hope that this is satisfactory to you. And that it shows you BOTH view points as I have been doing all along in spite of your comments.

PE

PE, i will go through my edition (first, third reprint, 1945) again to see if i can find the bits.
As i said, nothing about stop in it i could find so far (no mention in the subject index, no text about it in places it should appear, if a stop bath or rinse were discussed.)
This edition goes on about oxidized developer on p. 397 (section "The reactions of development"), and about speed, density on pages 709-10 (section "Interpretation of sensometric results".) From development straight on to fixation.

I know that you have given us both views. I have said so before.
My question was, what i don't understand is, why your preferred view (and i have absolutely no problem with someone having preferences) comes with gloomy tales of darkest doom (i'm overdoing it a bit, sorry! ) re the view you don't prefer.

Well, I cannot agree that my view is doom and gloom if you use a rinse! Actually the problems that I stated come from the references as you see for example in the Mees and James quote above (Written by G. Eaton BTW). And, that is why I have a preference.

I have said that I use both methods depending on a strict set of guidelines that I have developed (no pun intended) over my over 60 years of processing. For example I would never use a rinse with tank developed sheet films but sometimes use a rinse for a single roll of 35mm in a small tank. Too much chance for non-uniformity with the larger tanks or sheets. That is not doom and gloom, just prudent lab workflow.

If you reread the references I have posted the manufacturers and authors invariably either are balanced in POV or prefer a stop for film and all agree that a stop should be used for paper. Many resources give reasons and I have found those to be reasonable and something to be avoided if possible.

PE

See post #140 for scan of the orginal text by Mason....

I find it difficult to know where we stand at the moment,
perhaps you guys have progressed in your understanding of each others view,
I don't know.

I really do not want to participate at full power in this minor thread.

But I do want to note that rapid fixer as well as regular fixer apperas to be related to the German material I translated earlier, as both apperar to be advertised in that same publication and there was no statement disclaiming rapid fixers from the gist of the comments... it is true however that in general, ammonium based fixers were historically not the main fixer in common use.
How about today?
Does it change the essential truth of the observation?
Are ammonum fixers more or less likely to cause such troubles?

Please make your own decesions.

Re Mason:
Going from the cut and paste data...
Does someone have that reference?
I can't find it at this moment (name title date)

I was going to comment independantly,
but found PE has already and repeadtedly,
pointed out that Mason does not really say that stops are superfluous...

Yes he says those words but that is not his message.

What he is saying is:

When well-buffered acid fixers are used,
[the] stop bath stage is superfluous,
[in the sense that the required pH is present],
but the carryover of the developer by this technique
[of using no stop or just a water rinse]
does seriously shorten the life of the fixing bath...
Thus, a stop bath is desirable
if development is to be immediately arrested and
the life of the fixing bath prolonged."

I cannot see how this can be read as saying Stop Baths are Superfluous;
to me, I would say Mason feels that a stop bath is desirable.

100% necessary? Maybe not.

It's up to you.

???
Maybe we should adopt a "Don't ask - Don't tell" policy for this touchy subject.

Photo Engineer said:

Well, I cannot agree that my view is doom and gloom if you use a rinse! Actually the problems that I stated come from the references as you see for example in the Mees and James quote above (Written by G. Eaton BTW). And, that is why I have a preference.

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But, PE, (and that is the thing) the bits of Mees you quote don't talk about problems.
They say what an acid stop bath does. Something Mees earlier says stop dows. I have looked through other, early books too, and found repeated what Mees says in his 1st ed.

And i don't think it has been said before, but it must: a fixer is an acid stop bath, with extra ingredients that do more than a stop bath does. (Mees told us about that.)
The intermediate step, a rinse or a separate stop bath, is not meant to prevent any problems that you would run into when you don't. They are meant solely to extend the usefull life of the fixer.
Not to prevent what you again call "problems" (the things you say you too have never run into.)

Yes, quite true that an alkaline fixer is not an acid stop bath.
But what alkaline fixer?

Photo Engineer said:

I have said that I use both methods depending on a strict set of guidelines that I have developed (no pun intended) over my over 60 years of processing. For example I would never use a rinse with tank developed sheet films but sometimes use a rinse for a single roll of 35mm in a small tank. Too much chance for non-uniformity with the larger tanks or sheets. That is not doom and gloom, just prudent lab workflow.

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And nothing wrong with that.
Though your "too much chance" is hardly a scientific fact.

Photo Engineer said:

If you reread the references I have posted the manufacturers and authors invariably either are balanced in POV or prefer a stop for film and all agree that a stop should be used for paper. Many resources give reasons and I have found those to be reasonable and something to be avoided if possible.

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We keep going over this in this thread: your interpretation of what the literature says goes a bit beyond what we can see the books say.
And that's still the puzzling part. Yes, well balanced, and all that. But followed immediately by a one-sided condemnation. Why?