A quick question about stop bath

Creagerj

Creagerj

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What is a stop bath? I know it happens between developer and fixer when developing BW and thats about it. I heard once that water can be used as a stop bath, is that true. I'm about to start developing so this would be good to know.
 
I use water. A stop bath will stop the developer from, er, developing, more quickly, but some folks say it's hard on the negatives. I have no trouble with water.
 
So basically I would just run water into my developing tank before I put my fixer in and that would work?
 
a stop bath is an acid bath that instantly stops the development process. I prefer using an actual stop bath chemical. I have never seen any adverse effects from using it. However, I have often used water as a stop bath. In fact my current process involves using a particular fixer for which the manufacturer recommends using a water stop.

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I've used both. College told us to use water. When I bought all my stuff to do it at home I was given a bottle on indicator stop bath for free, so I use it.

The Stop bath acts as a neutraliser between Developer and Fix, which means you won't get your film contaminated as the two chemicals don't like each other very much.

Apparently Stop also prolongs fixer life. I'm not sure if this means on the neg, or in the bottle, however.

Stop isn't expensive so you may as well use it. It lasts almost forever too.
 
oh if you do use water, make sure you use running water for a couple minutes, or you will still have Dev on the negs and cause contamination (which ruined one of my early films!)
 
Joe, stop bath is cheap stuff and reusable. If you just use water and your negs are over-developed it'll just be another variable you'll have to consider, you'll wonder if you souped too long or if you failed to stop..... and trust me you will screw up some negs at some point. Messing with super thin dilutions, stretching number of uses of chemicals, shooting at crazy EI's, and making your own developer out of banana skins etc. are best left to experienced darkroomers who know what they're doing (and don't mind if they blow a roll.) There are plenty of things to worry about (times, temperatures, dilutions, agitations) before you start experimenting.
Just my $.02.....
 
White distilled vinegar is the same acidity as stop bath. I use a 10% solution of white vinegar (1:10, vinegar to water) as my stop bath for film and for paper. No adverse effects in ten years, and you get the benefits of precisely stopping the developing action with absolutely no ill effects for the environment. Plus, it's really cheap. You probably have some in your kitchen already.
 
Vinegar, Citric Acid, Stop Bath etc have the same impact on the environment : none if diluted enough.

The best thing that happend to film after development is to be bathed into "something" that stops development and is reasonably at the same temperature as the developer. "stopping" using 20C water is probably fine, but stopping using 10C tap water is most probably bad for the emulsion...

But as said several times, stop bath with indicator is cheap, and last forever, AND you can keep it at the same temp as the dev easily, AND you stop development instantly giving you reproducible results...
 
Here is another question, when I mix developer and fixer for one roll of film how much solution should I mix? Enough to fill the container or what?
 
Creagerj said:
Here is another question, when I mix developer and fixer for one roll of film how much solution should I mix? Enough to fill the container or what?
Click to expand...

Are you talking about mixing dev and fix to a stock solution (e.g., from a package), or are you talking about mixing to a working solution?

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I guess I want to know how much I should mix if I was just using it on a one shot basis. I don't really know the difference between the two terms.
 
You should reuse the fixer! Just buy a couple of 500ml plastic bottles, make your stop bath, make your fixer and you will have enough for 15 to 30 films. And with 500ml you can dev 120, or 2 135 at the same time.
Just pour it back into the bottle after you souped the film...

That even if you use a one shot developer...
 
Or if your dev. time is over 4-5minutes and your fixer is acidic, you can skip stopbath altogether with no ill effects.
 
If you have a container of powder developer or fixer and it says "to make 1 gallon" then it is best to mix up the whole gallon. It is not advisable to mix smaller quantities because the contents of the bag are a mixture of ingredients and you may throw off the ratios if you try to divide the powder and mix say two 1/2 gallon batches. If you are using liquid chemicals then by all means just mix up enough to fill the tank. Most tanks have the volume needed marked on the bottom. If not, place empty reels in the tank and fill it with water (to cover the top-most reel completely) and then pour off and measure the volume of the liquid. I do this even if the amount is marked on the tank.
Stop bath is vinegar... but most stop bath has a color indicator of acidity (like built-in litmus paper) something not needed in cooking or cleaning. It is all about the ratio of acid to water. The above dilution of 1:10 will work fine, is cheap and can be used for other things as well. In all honesty a stop bath is really not needed if you use a water rinse and really is not needed if you don't re-use the fixer.
 
There used to be a concern that the gassing action of mixing the akaline developer and the acidic stop bath could cause pinholes in the emulsion. For this reason, I learned to just use a water rinse between developer and fixer. Been doing it for 60 years, and my father 30 years before that, and it works fine.
For prints, especially fiber base paper, stop bath should be used, as the paper has soaked up a lot of developer. While this won't hurt the process, but it significantly shortens the life of the fixer.
So far as how much developer to use - yes, enough to cover the reels is necessary. You many want to consult the developer instructions, as some list a minimum quanity per roll. To little and full development won't take place as the developer becomes exhausted.
As the advice above, powder mixes should use the entire container. With something like Rodinal, just mix what you need. I usually use the one shot method rather than replenshing. I think it gives more consistancy, and mixed developer doesn't sit around oxidizing for weeks.
Just IMHO :cool:
 
While I agree that acid stop is not essential, I used to use a water rinse and my fixer exhausted in a ridiculously short time. I switched to acid stop (either Ilford or Fotospeed odourless) and find the extended fixer life easily pays for the stop bath. I print too so I'd have the stuff around anyway.
 
Probably also depends a lot on wether your tap water is acidic or not. Mine is slightly acidic, that helps a lot for alternative processes. But I would still use stop bath for film. I don't think pinholes can happen if the dilution is correct..
 
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