Stop Bath.. How important?

[Ian Grant]

Yep. Which is why I'm with you. The water stop guys are so out of touch.

Out of touch with reality.? Only used water stop for the last 5 yrs with no problems but the water here is very soft so that maybe a problem to some and water the same temp as developer rinse 2x.

The reality is Kodak, Ilford, Fuji etc all recommend using Stop bath OR a Water rinse when processing films. So who is out of touch ?

Not Dennis.

Ian

 

[faberryman]

I am sort of wondering what was going through the guy's mind who first decided to ignore the instructions and just use a water rinse. Was he out of stop bath or just a contrarian? Was he trying to save a nickel or was he curious about what would happen? What else did he do? Did he decide not to change the oil or top off the anitifreeze in his car? Did his wife leave out the sugar in the cookie recipe?

 

[Sirius Glass]

I am sort of wondering what was going through the guy's mind who first decided to ignore the instructions and just use a water rinse. Was he out of stop bath or just a contrarian? Was he trying to save a nickle or was he curious about what would happen? What else did he do? Did he decide not to change the oil or top off the anitifreeze in his car? Did his wife leave out the sugar in the cookie recipe?

Just saving the big bucks by not using stop bath.

 

[Dennis S]

The reality is Kodak, Ilford, Fuji etc all recommend using Stop bath OR a Water rinse when processing films. So who is out of touch ?

Not Dennis.

Ian

Check out the instructions on using TF 4 fixers as the RECOMENDATIONS state "do NOT use stop bath" so I really don't think we should use the recommendations of someone else on the internet as fact. I do believe the instructions by the engineers of the chemicals are the best to use.

 

[npl]

Is stopping to much possible ? I use Tetenal Indicet, there is no manual that I know of, but it says on the bottle : "Time : 10 - max. 20s"

I use it for both film and paper, and once it was used a few time my habit is to poor the stop bath, agitate the tank for 30s, then let it sit for 30s. What's the worst that can happen if the film is staying too long in there ?

 

[MattKing]

Ron Mowrey was a co-developer of TF-5 fixer. He commented many times about the compatibility of the TF fixers with stop bath. For example, a couple of posts here: https://www.photrio.com/forum/threads/alkaline-vs-acid-fixers.3850/page-2#post-49911

 

[alanrockwood]

I am restricting my comments below to film processing, not print processing.

Let's think about it this way. What are the possible reasons for using an acid stop bath rather than a water "stop bath"? The way I see it, in the grand scheme of things there are two possible reasons.

1. Using an acid stop bath somehow yields better photos than using a water stop bath because an acid stop bath somehow produces produces superior negatives than those produced using a water stop bath.

2. Using a water stop bath results in faster degradation of the fixer than using an acid stop bath, by which I mean a measurable difference that also makes a practical difference. (For example, a 2% difference in fixer lifetime might be measurable, but is it different enough that anyone would care?)

This discussion is filled with endless speculation about these two points, with various people arguing pro or con, but what is conspicuously missing in the discussion is experimental evidence that supports the speculative arguments being made here.

So here is the challenge: Show us the evidence!

One subtle qualification to the challenge: It needs to be recognized that develop time might need to be (very) slightly adjusted to account for the fact that a water stop bath is slower acting than an acid stop bath. How much adjustment? I don't know, but as a wild guess I would think that shortening the development time by 15 seconds when switching to a water stop bath would probably be more than enough to compensate for this effect.

 

[Dennis S]

Ron Mowrey was a co-developer of TF-5 fixer. He commented many times about the compatibility of the TF fixers with stop bath. For example, a couple of posts here: https://www.photrio.com/forum/threads/alkaline-vs-acid-fixers.3850/page-2#post-49911

I read that and further down that post is a person (Bruce Osgood) who uses close to the same method I do without his sanity being challenged like here. I always use some sort of Pyro developer and water rinse is recommended there for a stop bath on them all. I did use a stop bath on a few rolls to begin with but I didn't like the results so the less chemicals I use in the tank the better the final look. The TF 4 that I use has a better longevity than any other fixer I have used.

 

[Sirius Glass]

I am restricting my comments below to film processing, not print processing.

Let's think about it this way. What are the possible reasons for using an acid stop bath rather than a water "stop bath"? The way I see it, in the grand scheme of things there are two possible reasons.

1. Using an acid stop bath somehow yields better photos than using a water stop bath because an acid stop bath somehow produces produces superior negatives than those produced using a water stop bath.

2. Using a water stop bath results in faster degradation of the fixer than using an acid stop bath, by which I mean a measurable difference that also makes a practical difference. (For example, a 2% difference in fixer lifetime might be measurable, but is it different enough that anyone would care?)

This discussion is filled with endless speculation about these two points, with various people arguing pro or con, but what is conspicuously missing in the discussion is experimental evidence that supports the speculative arguments being made here.

So here is the challenge: Show us the evidence!

One subtle qualification to the challenge: It needs to be recognized that develop time might need to be (very) slightly adjusted to account for the fact that a water stop bath is slower acting than an acid stop bath. How much adjustment? I don't know, but as a wild guess I would think that shortening the development time by 15 seconds when switching to a water stop bath would probably be more than enough to compensate for this effect.

And who is going to do exhaustive scientific tests with and without stop bath?

 

[Vaughn]

I am sort of wondering what was going through the guy's mind who first decided to ignore the instructions and just use a water rinse. Was he out of stop bath or just a contrarian? Was he trying to save a nickel or was he curious about what would happen? What else did he do? Did he decide not to change the oil or top off the anitifreeze in his car? Did his wife leave out the sugar in the cookie recipe?

More likely the use of a water stop bath preceding the use of an acid stop bath.

 

[Sirius Glass]

More likely the use of a water stop bath preceding the use of an acid stop bath.

But that does not stop the film development nearly as quickly as stop bath. Why would Kodak, Ansco and many others spend large amounts of money of R&D research for stop bath. Are you saying that they were addlepated?

 

[Vaughn]

There was photography before Kodak, Ansco, and many others...

 

[Sirius Glass]

There was photography before Kodak, Ansco, and many others...

So when a new method or product has be inverted, then one should never use it because it was never used before, right?

 

[Vaughn]

Why am I reminded of the album "Stop Making Sense"?

 

[Dennis S]

The reality is Kodak, Ilford, Fuji etc all recommend using Stop bath OR a Water rinse when processing films. So who is out of touch ?

Not Dennis.

Ian

I said I use water stop bath so what part of that didn't you understand?

 

[Kino]

Boxers or briefs?

Choose what you like.

 

[Sirius Glass]

I said I use water stop bath so what part of that didn't you understand?

Water stop bath is not stop bath, it is water used instead of stop bath and that is the heart of the discussion.

 

[MattKing]

A water stop is of course also a type of stop bath. It is just we usually refer to the special purpose chemicals like Ilfostop or Kodak Indicator Stop Bath colloquially as "Stop Bath", so the discussion here is about water stop bath vs. the other types of Stop Bath.
And my link to the Ron Mowrey posts was in response to those who say that TF-4 et al should not be used with (acidic) Stop Bath - he indicated that TF-4 et al is compatible with acidic Stop Baths - you can use those Stop Baths with them.
Even the Formulary material is inconsistent - in one part saying that acidic stop baths are not necessary, in others saying not to use acidic stop baths with TF-4 for prints.
A properly instigated, running water water stop is quite effective. If that is the workflow you prefer, go right ahead. Other implementations of a water stop are problematic.

 

[Sirius Glass]

A water stop is of course also a type of stop bath. It is just we usually refer to the special purpose chemicals like Ilfostop or Kodak Indicator Stop Bath colloquially as "Stop Bath", so the discussion here is about water stop bath vs. the other types of Stop Bath.
And my link to the Ron Mowrey posts was in response to those who say that TF-4 et al should not be used with (acidic) Stop Bath - he indicated that TF-4 et al is compatible with acidic Stop Baths - you can use those Stop Baths with them.
Even the Formulary material is inconsistent - in one part saying that acidic stop baths are not necessary, in others saying not to use acidic stop baths with TF-4 for prints.
A properly instigated, running water water stop is quite effective. If that is the workflow you prefer, go right ahead. Other implementations of a water stop are problematic.

If as you posted using water is so effective, why was so much money used in research and development for stop bath, as though there is no purpose for stop bath. There is a logical disjunction.

 

[MattKing]

If as you posted using water is so effective, why was so much money used in research and development for stop bath, as though there is no purpose for stop bath. There is a logical disjunction.

Because running water is way less efficient and effective for high volume commercial processing - the sort of environment that a lot of photo chemicals are optimized for.

 

[Sirius Glass]

Because running water is way less efficient and effective for high volume commercial processing - the sort of environment that a lot of photo chemicals are optimized for.

Good finally a direct answer why stop bath is used in one situation. Other reasons one way or the other, please.

 

[MattKing]

Everything under the sun/safelight has already been listed in the thread!

 

[Mr Bill]

But that does not stop the film development nearly as quickly as stop bath. Why would Kodak, Ansco and many others spend large amounts of money of R&D research for stop bath. Are you saying that they were addlepated?

You might not realize that when Kodak came up with the current color processes, C-41 for color neg film, and RA-4 for color paper, THEY DID NOT USE A STOP BATH. Probably more film and paper has been processed this way, including Fuji/Konica, etc., versions, than anything else in history (although I'm guessing on this). Anyone following the official process DOES NOT USE A STOP BATH.

I'm from an outfit where I spent years being personally responsible, as QC manager, to oversee the "process control," as well as the chemical analysis and final screening of all chemical mixes before use. In our main processing lab we ran several miles per day of C-41 film as well as a vastly larger amount of RA-4 color paper. My department also oversaw similar in several satellite labs, although they did not generally regenerate their chems. So I'm not just guessing at these things.

Having said this I should point out that these processes DO follow the developer with a lower pH bath that DOES halt the development fairly quickly. In the case of C-41 film this is a bleach; the first versions ran at pH ~6.5, as I recall. In the case of RA-4 paper this is generally a bleach-fix, aka blix, which combines a bleach and fixer together. The earliest version ran at pH running about 7.0, as I recall (depending on tank configuration - a single process tank ran a bit lower).

I should also point out a difference between commercial processing machines and small scale/amateur processing. The commercial machines generally use some form of squeegee between tanks, such that excess developer is stripped off the surface of the film before film enters the following solution. Then that following solution generally is mechanically circulated. Consequently there is little problem with "streaking" on the film.

In small scale processing, such as hand tanks, there's no clear way to quickly flush the developer off the film, so streaking could be a big problem. So it might be necessary to add a stop bath to the hand process.

Fwiw I'm specifically avoiding the topic of b&w films.

 

[Sirius Glass]

You might not realize that when Kodak came up with the current color processes, C-41 for color neg film, and RA-4 for color paper, THEY DID NOT USE A STOP BATH. Probably more film and paper has been processed this way, including Fuji/Konica, etc., versions, than anything else in history (although I'm guessing on this). Anyone following the official process DOES NOT USE A STOP BATH.

I'm from an outfit where I spent years being personally responsible, as QC manager, to oversee the "process control," as well as the chemical analysis and final screening of all chemical mixes before use. In our main processing lab we ran several miles per day of C-41 film as well as a vastly larger amount of RA-4 color paper. My department also oversaw similar in several satellite labs, although they did not generally regenerate their chems. So I'm not just guessing at these things.

Having said this I should point out that these processes DO follow the developer with a lower pH bath that DOES halt the development fairly quickly. In the case of C-41 film this is a bleach; the first versions ran at pH ~6.5, as I recall. In the case of RA-4 paper this is generally a bleach-fix, aka blix, which combines a bleach and fixer together. The earliest version ran at pH running about 7.0, as I recall (depending on tank configuration - a single process tank ran a bit lower).

I should also point out a difference between commercial processing machines and small scale/amateur processing. The commercial machines generally use some form of squeegee between tanks, such that excess developer is stripped off the surface of the film before film enters the following solution. Then that following solution generally is mechanically circulated. Consequently there is little problem with "streaking" on the film.

In small scale processing, such as hand tanks, there's no clear way to quickly flush the developer off the film, so streaking could be a big problem. So it might be necessary to add a stop bath to the hand process.

Fwiw I'm specifically avoiding the topic of b&w films.

I am aware that Ron Mowery, PE, advised using stop bath for the C-41 development process. Thank you for posting that for others to see and learn.

 

[mshchem]

Alkaline developers need to be neutralized. An acid stop will protect the longevity of acid fixing baths, it also helps to prevent dichroic fog.