Stop Bath.. How important?

2F/2F · Oct 9, 2010

Yes, you can do that, but I would not do it using water straight from the tap. I'd keep some water in a container in the cabinet with all your other chemicals so that every solution is close to the same temperature. It need not be store-bought water, but it should be bottled by you ahead of time and kept alongside your other chemicals and your water supply that you use for mixing processing solutions. (If you use tap water to mix your processing solutions, I suggest pre-bottling this as well, for the same reason.) There is some room for slop, but temperature differences between solutions should not be taken lightly.

Additionally, I would use the water for longer than you would use the stop bath, and I would agitate more as well. Stop bath has done its thing in 15 to 30 seconds with just a few inversions, but it takes more time and agitation to rinse the developer out of the film. When I skip stop bath (which I usually do only when processing in open tanks), I do one minute with constant agitation, dump the water, then do the same thing again before going to the fixer.

ymc226 · Oct 9, 2010

Thanks. My reason for considering water instead of the Kodak stop bath is that I want to have 4 tanks (1500cc each) going at once and don't want to have 6 L of stop bath pre mixed as I use it one time and throw it out.

Q.G. · Oct 9, 2010

ymc226 said:
Thanks. My reason for considering water instead of the Kodak stop bath is that I want to have 4 tanks (1500cc each) going at once and don't want to have 6 L of stop bath pre mixed as I use it one time and throw it out.

Just stop doing that!

nickandre · Oct 9, 2010

Vinegar works fine. 1-4 works fine for single use, use 1-1 or 2-1 if you'll be reusing it.

and you can reuse stop bath until it turns purple. That takes a looooong time.

2F/2F · Oct 9, 2010

tiberiustibz said:
Vinegar works fine. 1-4 works fine for single use, use 1-1 or 2-1 if you'll be reusing it.

and you can reuse stop bath until it turns purple. That takes a looooong time.

I think that vinegar may actually be more expensive in many cases...and it doesn't tell you when it has pooped out.

With one $7 bottle of Kodak Indicator Stop Bath having lasted me four years, and still having 1/3 of the bottle left (meaning that I am spending about a dime per month on stop bath), I would not even consider the cost of stop bath when deciding whether or not to use it or vinegar. Then again, I re-use the working solution until it goes purple or loses its sharp smell. (Then I pour it in with my spent fixer for disposal at a local hazardous waste roundup facility.)

Mainecoonmaniac · Oct 9, 2010

I don't use stop bath for processing film because I've had
Pin holes from acid shock. Does anybody else experience the same?

Anon Ymous · Oct 9, 2010

Mainecoonmaniac said:
I don't use stop bath for processing film because I've had
Pin holes from acid shock. Does anybody else experience the same?

Perhaps it would be useful to tell us what film - developer combination caused pinholes. FWIW, it has never happened to me, but I only use films from major manufacturers and I've never used a developer with carbonate.

clayne · Oct 9, 2010

ymc226 said:
Thanks. My reason for considering water instead of the Kodak stop bath is that I want to have 4 tanks (1500cc each) going at once and don't want to have 6 L of stop bath pre mixed as I use it one time and throw it out.

Stop dumping your stop bath after one use. It doesn't matter how much random crud is in it - it's not going to affect the image anyways.

Mainecoonmaniac · Oct 9, 2010

The film/developer combo is 4x5 FP4 and HC-110. Now my other question is will not using stop bath kill your fixer faster?

Ronald Moravec · Oct 9, 2010

I use nothing. Fix is one time use for film IMHO so it does not matter if you shorten the life a bit. Use it on test prints. That is unless you like to spot prints.

40 years ago I used SS, then water, now nothing. Quality is best with no SS and Photographers Formulary TF4 alkaline fix. Certanly you do not want base, acid, back to base.

hrst · Oct 9, 2010

Now my other question is will not using stop bath kill your fixer faster?

No, if you wash long enough. Acid stop bath indeed helps to maintain fixer pH, but this is relevant only if you compare to single water bath (or no bath at all). If you do 3 to 4 subsequent washes (water changes), as suggested everywhere, it will dilute the alkalinity to practically zero. There is some dilution of fixer (thiosulphate), but this is true also for stop bath.

And if you are so worried about water bath not being good enough for process or fixer, don't even think reusing the stop bath. Developer keeps accumulating to it . The only thing it does is maintain pH.

fschifano · Oct 10, 2010

Mainecoonmaniac said:
I don't use stop bath for processing film because I've had
Pin holes from acid shock. Does anybody else experience the same?

Never. Not once. What I had thought were pinholes on my sheet film turned out not to be. You can feel a pinhole. Mine turned out to be dust stuck to the film before exposure.

Q.G. · Oct 10, 2010

Not reusing stop bath until it can't 'stop' anymore is just crazy.
Reusing it is the anwer to the OP's problem/question.

RobertV · Oct 10, 2010

Exactly. Using a 1,5% stop is fine, even for staining developers. 15g/ltr. Citric Acid in 1 ltr. water.
Most commercial stops have an indicator from Yellow to Blue (pH > 5,5). 1+19 - 1+29.
Water will not stop developing, only it slows down the process. A stop immediately stops the developing process and you have less contamination of the fixer. For an Acid type fix you can leave the stop but for an Alkaline fix you need a stop.

About lifetime of the stop: You can re-use it many times. One liter maybe 15-20 films but with Citric Acid you need to take care you have no bacterial grow in the stop when it stays for a long time.
With developers containing high amounts of Carbonates in theory you could have some degassing on the film surface but I never had any problem with any film. Even the so called problematic films like Foma and Efke, softer emulsions and often reclamations on pin holes did not show any probems for the last 12 years which I am using Fomapan (35mm and 120 roll -) films from the Czech Republic.

hrst · Oct 10, 2010

No, YOU DO NOT NEED A STOP BATH for film -- not even for alkaline fix.

PLEASE, could you please stop spreading misinformation.

You can use it, you might even want to use it (I don't see a reason, but this is a matter of taste) but you don't need to. Using the recommended procedure of washing with three water changes dilutes the alkalinity so low that any buffer in fixer will take care of it.

Acid stop is not magic. It just maintains pH. It DOES NOT stop the development instantly, it still takes time for acid to diffuse in emulsion (correct words would be: it's somewhat faster than water.) It DOES NOT magically kill contamination, all it does it maintains pH by neutralizing alkalinity of developer. Of course, by doing this, it guarantees that even when there is developer contamination in fixer, it won't work at pH that low. But, by a decent 4-step water stop, you can eliminate most of the developing agent in fixer in the first place.

E6 uses no stop bath even when it's a color process where the stopping speed is very important for color balance and crossover. Usage of water has been designed in process times. Water works! It stops the development in a consistent enough time even for a color process, let alone BW work. And consistency is what counts.

And how do you define "contamination of fixer"? If you are talking about rising pH, you are right, using acid stop bath will actually lower the pH, but if you are talking about "contamination from developer", the game is clear: using water bath with three water changes as suggested will LOWER the fixer contamination from developer compared to a stop bath! Especially, if you compare to reusing the stop bath. This is not probably so important, fixer withstands contamination from used stop bath (and thus, developer) quite well, but you are talking about contamination as your argument against water bath, and you are wrong. Using water baths as suggested leads to less contaminated fixer.

And I'm sure if we go deeper into chemistry, we find many small facts to favor acid stop or water stop. Both have their supporters, both have their arguments. And both work.

Both work, use what suits your personal needs and taste! This is not very important matter so let's not make it religious and let's keep doors open.

Mainecoonmaniac · Oct 10, 2010

You might be right

fschifano said:
Never. Not once. What I had thought were pinholes on my sheet film turned out not to be. You can feel a pinhole. Mine turned out to be dust stuck to the film before exposure.

There's no excuse for poor film holder hygiene so what if I got my film process time and temp dialed in? If I use stop bath, do I increase my processing time slightly to compensate for processing times based on water only stop. Or should I just stick to the same processing time?

hrst · Oct 10, 2010

If you change from water to acid stop or vice-versa, there might be a small difference in development time, but it may be so small you won't notice it... I would compensate by 15 seconds or so. Just a hunch.

fschifano · Oct 10, 2010

The difference is so slight as to be insignificant. I can't tell the difference. If I had a densitometer and I was able to control everything else to a very fine degree, I might be able to measure it. In practical terms though, don't even worry about it.

RobertV · Oct 11, 2010

If I had a densitometer and I was able to control everything else to a very fine degree, I might be able to measure it.

Yes, you can measure it till about 8-10 minutes developing time. So if you're going on consistensy you could make the decision for developing times till 10 minutes with a stop and above without a stop.

When having 4x water change you also need water on the same temperature. Just when using a stop all chemicals should be already on the same temperature. So your process is less complicated too unless you want to run in unwanted reticulation on a certain moment.

clayne · Oct 11, 2010

The crazy thing about these threads is that I can never figure out, other than availability, why people wouldn't just get over it and use a stop bath.

Less time, less hassle, less complexity.

Steve Smith · Oct 11, 2010

clayne said:
The crazy thing about these threads is that I can never figure out, other than availability, why people wouldn't just get over it and use a stop bath.

Perhaps some people don't want to use something if they don't need to.

Steve.

RobertV · Oct 11, 2010

The crazy thing about these threads is that I can never figure out, other than availability, why people wouldn't just get over it and use a stop bath.

Less time, less hassle, less complexity.

I can only agree with you.

And about availability: Citric Acid (15g/ltr.) or Acetic Acid (99,5% (Glacial), 15% (cleaning) or white vinegar) should not be any problem to get one of these.

In the practical way when I am changing the fixer (6-10 films 500ml) I am changing the stop (Citric Acid) too. I do not like to keep working solutions over a longer time. And if you look at the costs of some chemicals, it's a fraction of the overall costs in photography. And for the work: I like liquid chemicals, fast and easy, no hassle outside the darkroom with powders. Making a new set (stop + fix) is just minute work.

clayne · Oct 11, 2010

Steve Smith said:
Perhaps some people don't want to use something if they don't need to.

Steve.

Okay. Fill a tank 3 times or fill a tank 1 time. How valuable is your time?

BetterSense · Oct 11, 2010

Okay. Fill a tank 3 times or fill a tank 1 time. How valuable is your time?

I only fill my tank up with water 1 time for the 'stop' step. It works fine.

I also use plain water (the same water I presoak in) as 'stop' when I develop sheet film in hangers. This saves me a whole tank of chemicals that I don't have to set out and maintain 2L of, and store somewhere in my tiny darkroom.

Steve Smith · Oct 11, 2010

BetterSense said:
I only fill my tank up with water 1 time for the 'stop' step. It works fine.

Me too.

I think it's a mistake to think that there is only one correct way to do things. When this train of thought is applied it usually escalates into "only my method is correct".

Steve.

Stop Bath.. How important?

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