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.
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.
Now my other question is will not using stop bath kill your fixer faster?
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.
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.
Originally Posted by Mainecoonmaniac
Not reusing stop bath until it can't 'stop' anymore is just crazy.
Reusing it is the anwer to the OP's problem/question.
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.
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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.
Last edited by hrst; 10-10-2010 at 07:07 PM. Click to view previous post history.
You might be right
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?
Originally Posted by fschifano
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.
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.
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.
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.
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.