MattKing
Moderator
Oops - closer to 32 litres (not 64 litres) of working solution.
It actually is 32 US quarts, but it will work just as well if you dilute it that extra little amount to 32 litres.
Oops - closer to 32 litres (not 64 litres) of working solution.For 64L of working solution?
The whole point of the indicator in Indicator Stop Bath is so you can tell at a glance (in the storage bottle, if clear(ish) or in the graduate before pouring into the tank or tray) that the stop bath is still yellow (= good). If you're going to toss your stop bath after each used, you don't gain anything from the bromocresol purple (it's photographically inactive) and further don't need to have even as much as 2% acetic acid -- 1% should be plenty, and 1/2% might be okay. Buy the cheapest distilled white vinegar you can find, and dilute it 1+4 to make 1% acetic acid solution, you've got an adequate one-shot stop bath.
For those of us who are willing to store our stop bath and watch for the indicator to change or get pale, we get a couple dozen rolls per liter mixed per Kodak instructions -- the indicator thus making Indicator Stop Bath the cheapest stop bath (comparable to plain tap water for many folks who pay for city water). I just discarded my old stop bath and mixed fresh a couple weeks ago -- that two liters had been used for about fifteen rolls since I got it out of a twelve year storage and who knows how many before that. As a confirmed cheapskate, I'm a firm believer in commercial Indicator Stop Bath (though I also have some 75% acetic acid and a small bottle of bromocresol purple indicator that I think was comparable in final cost, given that I'll dilute that acid about 1+36 or so to get working strength).
But we all know that stop bath with indicator is just so damned expensive!
Hi Donald, Thank you for the perspective. I have been a bit spoiled in my splurging on the occasional (Ok, once every 5 years) bottle of stop bath. But I am one photographer who may not produce the volume of film that most photographers do... let alone a classroom full of photographers. And no, NOT tongue in cheek. I genuinely appreciate your perspective.The whole point of the indicator in Indicator Stop Bath is so you can tell at a glance (in the storage bottle, if clear(ish) or in the graduate before pouring into the tank or tray) that the stop bath is still yellow (= good). If you're going to toss your stop bath after each used, you don't gain anything from the bromocresol purple (it's photographically inactive) and further don't need to have even as much as 2% acetic acid -- 1% should be plenty, and 1/2% might be okay. Buy the cheapest distilled white vinegar you can find, and dilute it 1+4 to make 1% acetic acid solution, you've got an adequate one-shot stop bath.
For those of us who are willing to store our stop bath and watch for the indicator to change or get pale, we get a couple dozen rolls per liter mixed per Kodak instructions -- the indicator thus making Indicator Stop Bath the cheapest stop bath (comparable to plain tap water for many folks who pay for city water). I just discarded my old stop bath and mixed fresh a couple weeks ago -- that two liters had been used for about fifteen rolls since I got it out of a twelve year storage and who knows how many before that. As a confirmed cheapskate, I'm a firm believer in commercial Indicator Stop Bath (though I also have some 75% acetic acid and a small bottle of bromocresol purple indicator that I think was comparable in final cost, given that I'll dilute that acid about 1+36 or so to get working strength).
I remember your solution, Jay Brunner. That's why I kept my APUG subscription. God bless you...I don't get it. I solved this problem for all you people 16 years ago
Ooh shoot. that's so zen.“A stop is just the start of something else.”
But we all know that stop bath with indicator is just so damned expensive!
It is when you're on a school budget
I remember well when up-front cost was much more of a concern than unit cost -- the days when I couldn't have bought, say, 200 gallons of gasoline ahead even if it saved me forty or fifty cents a gallon, or when ten dollars for enough stop bath concentrate to last several years meant a dent in my ramen and mac&cheese supply compared to just enough white vinegar to make up a jug of stop bath. For those in that state, I'd suggest sticking with tap water. Most such aren't paying their own water bills anyway, and the amount of extra water in processing film vs. reusable stop bath is insignificant (I can process film with one-shot developer and an Ilford wash in about a gallon for a roll; water stop bath adds a quart; neither one will be visible on most water bills anyway). But for those interested in controlling their annual total spending on photography, and who are already using the least costly film and paper available for most purposes, reusing stop and fixer and replenishing developer are the way to go.
So you would rather risk your students' negatives and prints, because they did not know that the stop bath was expired? Yes, that justifies throwing out all logic because we all know just how damned expensive stop bath with indicator is. Gee if the cost of stop bath is going to destroy the economy of the known world, maybe photography is something you should not do.
No, "For those in that state, I'd suggest sticking with tap water. " Tap water is a fairly poor alternative to stop bath, but if you use the same method all the time, you'll get consistent results -- which would not happen if your stop bath without indicator rose in pH above around 7.5. Or one could use white vinegar diluted 1+4 (half the strength of commercial stop bath mixed to instructions) to 1+9 (1/4 commercial working solution strength) as a one-shot, which will work and will stop ten or so rolls of 35mm for a couple bucks. False economy is sometimes the only kind you can afford (and students in this financial condition are likely to be using dodgy cameras and the cheapest film and paper they can find, too).
Of course, if the school darkroom is supplying the developer, stop bath, and fixer, then the student is off the hook (presuming someone paid their lab fee at tuition time).
I'm very serious about the cost of a bottle of stop bath concentrate affecting one's food budget, for some students -- so apparently those students should drop out of college and move back into Mom's basement, rather than learning analog photography, because nothing you can learn could possibly be worth having to make some hard choices.
Stop bath should do what it's name implies, stop development. Water just slows it down.
But it can also wash out most of the developer in the emulsion, which protects the fixer.Stop bath should do what it's name implies, stop development. Water just slows it down.
But it can also wash out most of the developer in the emulsion, which protects the fixer.
No - but the difference with film is marginal, IF there is sufficient time, and sufficient flow.Are you talking about stop bath or water? If water, it does not protect an acid fixer as well as an acid stop bath.
Stop bath should do what it's name implies, stop development. Water just slows it down.
Oh I agree the cost of stop bath can drive people to get in bread lines.
Thank you. Yes, and if I recall your opinion is that water works just fine. I don't know about prints, but for film I am 99.99% sure that this is true.I don't get it. I solved this problem for all you people 16 years ago
Do you really expect us to believe you were so silver-spoon that you never had to worry about money when you were in college? Okay, if you say so. I was talking about student budgets, not the department (or instructor, in today's educational environment) -- and given that students new to photography (and possibly new to actually following instructions) are likely to make one-shot or one-session chemicals a good decision (so Syd's crossup between stop bath and fixer doesn't result in Georgie's "fixer" leaving the film milky), the cost of stop bath can still have an impact. You can exaggerate for ridicule all you like -- but if it isn't free, it's going to be a decision for someone, rather than a no-brainer.
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