Stop Bath.. How important?

[faberryman]

With the staining developers i use, the benefit is not having an acid stop bath followed by an alkaline fixer.
After developer, i use one minute with agitation for roll film and 1-2 minutes for sheet film processing in trays

I understand that stop bath is not recommended when processing film using staining developers. Do you also not use stop bath when printing either?

 

[koraks]

With the staining developers i use, the benefit is not having an acid stop bath followed by an alkaline fixer.

That's irrelevant though. An acidic stop bath doesn't inhibit or reduce the stain, nor does an acidic fixer. These are just myths that keep being perpetuated, possibly out of conservatism. They don't appear to be grounded in fact or empirical observation.

 

[faberryman]

When you say "out of conservatism" do you mean "out of an abundance of caution", or something else? If you develop your film in a staining developer, do you use stop bath or water, and why?

 

[GregY]

That's irrelevant though. An acidic stop bath doesn't inhibit or reduce the stain, nor does an acidic fixer. These are just myths that keep being perpetuated, possibly out of conservatism. They don't appear to be grounded in fact or empirical observation.

Whatever... i don't have pinholes in my negatives and haven't used stop bath with film developing for 20 yrs.

 

[GregY]

I understand that stop bath is not recommended when processing film using staining developers. Do you also not use stop bath when printing either?

I do use stop bath when printing. (Diluted glacial acetic acid)

 

[GregY]

That's irrelevant though. An acidic stop bath doesn't inhibit or reduce the stain, nor does an acidic fixer. These are just myths that keep being perpetuated, possibly out of conservatism. They don't appear to be grounded in fact or empirical observation.

Koraks, often we do things depending on how we learn...& if it works we keep doing it. I was taught to use staining developers from a friend....& then from Hutchings Book of Pyro. This was before the advent of the internet & the forum of public opinion. The process worked well for me...so there was no reason to question the process or change the method.

 

[koraks]

@GregY sure, I get your reasoning. I posted my comment no so much to try and change your ways - 'you be you' and all that, and I mean it! I highlight the issue because we get new pyro users from time to time who are anxious to use for instance certain fixers or an acidic stop bath. I find it important to ensure that these people, if they stumble upon a thread like this, are offered both sides of the story - one side being let's say the historical one, the other the more empirical one. By the latter, I'm referring to the tests both @Andrew O'Neill and myself did at more or less the same moment, but independently from each other, with the same findings. You'll find these tests on Andy's YouTube channel and my blog.

 

[alanrockwood]

Are there any benefits to not using stop bath other than the nominal cost savings?

For film, how many water rinses do you use between developer and fixer?

For prints, how long do you leave the print in the water tray between developer and fixer?

Commenting only on stop bath for film development, using water instead of an acid stop bath is a simplification of the process because it is one less solution to prepare and store. Also, water doesn't smell bad. Acetic acid-based stop bath does smell bad, at least to me it smells bad.

On a related topic, I have followed this topic for a long time, and as far as I have been able to determine no one has ever shown actual experimental results demonstrating that using water in place of an acid stop bath has any effect detrimental to film. If it is true that using water in place of stop bath has no detrimental effect on film then the real question is why use an acid stop bath when water works just as well?

 

[Anon Ymous]

If it is true that using water in place of stop bath has no detrimental effect on film then the real question is why use an acid stop bath when water works just as well?

Personally speaking:

a) I already have stop bath.
b) I find it more convenient and simpler to use a single solution for 30" than several water rinses.

To each his own, but I use stop bath, even with Pyrocat HD.

 

[alanrockwood]

Personally speaking:

a) I already have stop bath.
b) I find it more convenient and simpler to use a single solution for 30" than several water rinses.

To each his own, but I use stop bath, even with Pyrocat HD.

Or, just do a single water rinse instead of several water washes. That's the standard process for Phototherm processors.

By the way, just to be clear, I'm not saying that that a water stop bath is better than an acid stop bath, just that no one has shown that an acid stop bath gives superior results.

Also, I'm not saying that people should quit using an acid stop bath if an acid stop bath what they want to use, just that it's not necessary to use an acid stop bath. In other words, use whatever stop bath you want, as long as you are happy with it.

 

[faberryman]

Why has Kodak included using stop bath in its film processing instructions since time immemorial? Did they have any scientific evidence for doing so or did they just make it up out of thin air so they could sell stop bath and make more money? Have materials changed over time eliminating the need for stop bath, and Kodak never got around to updating its directions? Did Kodak pay PE to recommend using stop bath on this forum? He seemed like a pretty knowledgeable guy. How else did he lead us astray? Do any books on film processing say stop bath is unnecessary, or is it just people on photo forums?

Of course, I'm fine with everyone doing whatever they want. As always, show me your prints.

 

[snusmumriken]

Why has Kodak included using stop bath in its film processing instructions since time immemorial? Did they have any scientific evidence for doing so or did they just make it up out of thin air so they could sell stop bath and make more money? Have materials changed over time eliminating the need for stop bath, and Kodak never got around to updating its directions? Did Kodak pay PE to recommend using stop bath on this forum? He seemed like a pretty knowledgeable guy. How else did he lead us astray? Do any books on film processing say stop bath is unnecessary, or is it just people on photo forums?

Of course, I'm fine with everyone doing whatever they want. As always, show me your prints.

You were talking about negatives, so did you mean ‘Show me your negatives?’

This thread continues to hold a horrible fascination. I can think of one circumstance in which it is reasonable, and one in which it may be desirable, not to use stop bath with film. I’m sure both must already have been covered in the preceding 46 pages of replies. The first is when the developer is very dilute or is being used in a 2-bath system - in these cases there is almost nothing to stop, and further dilution does the job effectively. The second is when the developer contains a strong alkali, such that a violent reaction with the acid stop might damage the emulsion - this has been claimed to cause pinhole defects. I can’t think of a good reason not to use stop bath in other circumstances, but dissenters may well get away with it and have nice negatives to show you!

The stop bath in printing is another matter.

 

[Sirius Glass]

Commenting only on stop bath for film development, using water instead of an acid stop bath is a simplification of the process because it is one less solution to prepare and store. Also, water doesn't smell bad. Acetic acid-based stop bath does smell bad, at least to me it smells bad.

On a related topic, I have followed this topic for a long time, and as far as I have been able to determine no one has ever shown actual experimental results demonstrating that using water in place of an acid stop bath has any effect detrimental to film. If it is true that using water in place of stop bath has no detrimental effect on film then the real question is why use an acid stop bath when water works just as well?

How about the fact that Kodak et al spent millions of dollars perfecting stop bath is a good indication that stop bath is important.

I do understand that stop bath with indicator is so damned expensive that it breaks some photographer's bank.

 

[faberryman]

This thread continues to hold a horrible fascination. I can think of one circumstance in which it is reasonable, and one in which it may be desirable, not to use stop bath with film. I’m sure both must already have been covered in the preceding 46 pages of replies. The first is when the developer is very dilute or is being used in a 2-bath system - in these cases there is almost nothing to stop, and further dilution does the job effectively. The second is when the developer contains a strong alkali, such that a violent reaction with the acid stop might damage the emulsion - this has been claimed to cause pinhole defects. I can’t think of a good reason not to use stop bath in other circumstances, but dissenters may well get away with it and have nice negatives to show you!

Thank you for responding to my post. Unfortunately, you did not address any of the issues I raised. Which makes me wonder why you responded to my post.

As for very dilute developers, I am only familiar with Rodinal and staining developers. Agfa recommends using a stop bath for all of its developers. The staining developers I am familiar with recommend using an alkali stop bath or water.

As for two bath developers, for example Barry Thornton's two-bath developer, the instructions say not to use stop bath, so unless someone just likes being perverse, no one uses stop bath.

As for alkali developers, which ones did you have in mind? I'll be happy to look them up and report back. We could start with the alkali developers you regularly use?

I don't approach film processing as an activity for seeing what I can "get away with." Nor do I understand the obsession with saving a nickel. The "dissenters" all seem to have a plethora of cameras and lenses, and are always on the look out to acquire more.

You were talking about negatives, so did you mean ‘Show me your negatives?’

I do not ask people to show me their negatives. The object of photography is not to create negatives. They are simply an intermediate step. I don't care what anyone's negatives look like. I have never seen anyone's negatives outside the classroom, or occasionally when some self-appointed expert does a show and tell on YouTube. I am interested in what my negatives look like.

I am interested in what people do. I am more interested in why people to do it. Only then can I decide whether to follow their lead.

I don't why you think the fascination this subject evokes is "horrible." It is merely an exploration of human nature. As are most of the threads on this forum.

 

[MattKing]

Stop bath is harder to screw up than water, because it doesn't need to be constantly flowing in order to ensure no developer carryover into fixer.
Just in case you need a reason

 

[snusmumriken]

How about the fact that Kodak et al spent millions of dollars perfecting stop bath is a good indication that stop bath is important.

I do understand that stop bath with indicator is so damned expensive that it breaks some photographer's bank.

C’mon, that’s a fable! It can’t have been more than a couple of days’ work.

Your second point is always good though.

 

[snusmumriken]

I do not ask people to show me their negatives. The object of photography is not to create negatives. They are simply an intermediate step. I don't care what anyone's negatives look like.

With all love and respect, all you will learn by seeing prints is that the photographer at least sometimes gets a printable negative and makes a decent job of printing it. I don’t see how you’d be able to tell whether they used stop bath on the film or not? Prolific output with consistent quality might be a different matter, I grant you.

 

[faberryman]

With all love and respect, all you will learn by seeing prints is that the photographer at least sometimes gets a printable negative and makes a decent job of printing it. I don’t see how you’d be able to tell whether they used stop bath on the film or not? Prolific output with consistent quality might be a different matter, I grant you.

Whooosh.

 

[alanrockwood]

Stop bath is harder to screw up than water, because it doesn't need to be constantly flowing in order to ensure no developer carryover into fixer.
Just in case you need a reason

The number of developer molecules carried over to the fixer will be essentially the same, regardless of whether one uses an acid-based stop bath of just plain water. It will only depend on the volume of liquid used in the stop bath, so if you use the same amount of liquid for the stop bath you will transfer the same number of molecules to the fixer, regardless of whether the stop bath is acidic or roughly pH neutral.


This analysis assumes that the developer carryover comes from the film of solution adhering to the surface of the film and the developer tank and reel. It does not include developer molecules that might be trapped inside the emulsion. There might be some subtle effect with regard to how many developer molecules might be removed from the actual film emulsion itself, but given the small volume occupied by the emulsion there must be very few developer molecules trapped in the emulsion, and even then one would have to propose that they are more easily removed under mild acidic conditions than under roughly pH neutral conditions.

 

[snusmumriken]

Whooosh.

I’m a humble fellow. What am I missing or misunderstanding or mistaken about?

 

[snusmumriken]

As for alkali developers, which ones did you have in mind? I'll be happy to look them up and report back. We could start with the alkali developers you regularly use?

I realise I need to reply to this with personal experience.

I used to use Tetenal Emofin as my standard (it is no longer made). With the thin Delta emulsions I started to notice lots of tiny blemishes. I read somewhere that the reason might have been the use of a stop bath, because Bath 2 of that product was strongly alkali and could cause a physically violent reaction (it was said). So I stopped using stop bath on my films. After a while, I realised that my blemishes were white in the positive, so they couldn’t have been missing bits of emulsion blown away by micro-explosions. I improved the filtration on my water supply and all chemicals, and the problem vanished. That’s why I said ‘may’ in my post above. It’s a widespread notion, but I’ve seen no definite proof.

Nevertheless, I realised that the amount of unused developer in bath 2 of my Emofin must have been very small, so a stop bath was probably not doing much anyway. That reasoning applies equally to the Barry Thornton 2 bath developer that I now use. I'm sure I could use a stop bath because I use metaborate in bath 2; but if I used a stronger alkali (there are several options mentioned by Thornton) I might wonder about that acid-alkali theory until I’d done a few films.

If I use a mainstream developer like ID-11, I use a stop bath.

 

[Sirius Glass]

C’mon, that’s a fable! It can’t have been more than a couple of days’ work.

Your second point is always good though.

The first line is without basis and it is well documented that that millions of dollars in R&D were spent by Kodak et al.

 

[Sirius Glass]

With all love and respect, all you will learn by seeing prints is that the photographer at least sometimes gets a printable negative and makes a decent job of printing it. I don’t see how you’d be able to tell whether they used stop bath on the film or not? Prolific output with consistent quality might be a different matter, I grant you.

You would have to look at the molecular level.

 

[BobUK]

As to Pyro and stop baths, I do not use one, water only.

The reason being, I spent a fair bit of time experimenting to find the true film ratings and, developing times for my favourite films in Pyro 510.
The information available to me at the time was No Acid Stop Bath.
I know my parameters for my films developed in 510 and a homebrewed Kodak fixer. I don't want to go over the same ground again using an acid stop bath.

 

[snusmumriken]

The first line is without basis and it is well documented that that millions of dollars in R&D were spent by Kodak et al.

On working out the appropriate concentration of acetic acid and indicator? Is it really more than a high school chemistry problem? Ah well, I’ve no reason to dispute it if it is documented.

You would have to look at the molecular level.

What would you see? Sometimes I can’t tell if you are joking.