can I buy just stop-bath indicator dye?

[gone]

3 parts water, 2 parts vinegar, assuming you have 5% vinegar. In the past I have mixed it 1+3 though.

 

[pentaxuser]

I think I recall PE saying that household vinegar may contain other ingredients that may be fine for its use in the household but less than ideal as a photographic stop-bath. Anyone else recall this?

If you drain the film tank of developer properly then add a full tank of water, invert several times then dump and do the same again then surely on even the first water rinse the developer has been diluted to such a low level that any extra development is equivalent to only a few seconds of extra development in what might have been over 600 secs

I have difficulty in seeing how this affects my film development to an appreciable degree. When I stopped using stop-bath for film I cannot recall ever noticing a difference in development compared to my stop-bath days

pentaxuser

 

[Photo Engineer]

Use white or distilled vinegar. That is what my conclusion was. Regular brown vinegar from fermentation or apples, wine or etc... Has great flavor but can be bad for film.

PE

 

[Rudeofus]

i used TF5 because it was the rage, idk 14 years ago ...
it REEKED, i never used it again, and got rid of what i had

Is there a chance you confused TF5 with something else?

 

[Roger Cole]

who has claimed it is too expensive to buy ?

i don't use it, not because it is too expensive
but because i don't wan to deal with additional chemistry.
and it is particularly nasty.

Stop bath is nasty??

 

[Roger Cole]

Stop bath with indicator does not smell.

Yes it does. At least, acetic acid does. The smell is not affected by the indicator.

I use a citric acid stop with indicator. It costs more. I must be a real spendthrift.

 

[Photo Engineer]

TF5 has no odor and is slightly acidic, TF4 has a slight odor and is mildly alkaline. Use of either without a running water rinse or a stop bath will cause a strong odor to come from the fix as it is being mis used and exhausted. A still water rinse carries over alkaline developer into the fix and exhausts it early. Of course, this is the case with all fixers.

PE

 

[Roger Cole]

So it is ok to use an acid stop with TF4 alkaline fix?

I have some TF5. Haven't gotten around to using it yet.

 

[Photo Engineer]

Yes Roger, you can use an acid stop. Just give the material (paper or film) a quick dip in water after and then into the fix.

If you don't mind a slight drop in pH then go right into the fix.

PE

 

[Gerald C Koch]

The idea behind Kodak Indicator Stop Bath was that while the bath would appear colorless under normal darkroom safelights (amber or red) the bath would appear black when it was no longer effective. The choice of bromcresol purple was deliberant for this purpose. This makes sense if you are making prints. There is no advantage to using it if you are developing panchromatic film.

 

[Roger Cole]

I think Gerald's point was that for film it doesn't matter what the color change actually is, just so long as you can see a chance. For black and white paper this particular indicator is ideal because of the appearance under safelights.

 

[Gerald C Koch]

Roger got my point. If you are working in absolute darkness what is the purpose of the color change.

For those that use ISB can you remember the last time when the stop bath was exhausted before the developer went south? In my experience stop bath is acidic enough to last through any reasonable length printing session.

 

[AgX]

You could. It is called bromcresol purple. It's fairly expensive.

Did a price quote $65 for 10 grams.

Much cheaper is ph indicator-paper. You can obtain it down to 0.3 increments.

 

[Gerald C Koch]

Stop bath is so reasonable there seems no point in saving it between sessions if you are dumping the developer. When I do use stop bath I never save it for reuse. This has always seemed to be a foolish economy as particulates may build up in the solution and be transferred to the emulsion. Film is expensive and stop bath cheap.

 

[AgX]

Build-up of emulsion particles would be a problem with fixer and developer too. Thus then those had to be used only once too.

But I agree, stop-bath is the least expensive. And concerning this aspect may be discarded after single use.

 

[Roger Cole]

I reuse it because I've never had a problem doing so. It's cheap but so what. If this particulate thing was a real problem I'd have no problem not doing so but it hasn't been so I don't. Shrug.

 

[Roger Cole]

I didn't explain myself very well, let me try again. I did get your point about not being able to see the color change while in the dark, but I frequently develop film one day and continue the next day; so I dump the developer at the end of day one but leave the SB in the tray for use on day two. I'd like to see the color change on day two under room lights after fixing a film, as the SB may be getting weak before developing the next film, and I can then make fresh SB and keep working.

But that's STILL not exactly the point. The point being, I think, that there are other indicators available, some of which are likely much cheaper, but this particular one was chosen anyway because of that safelight appearance. If that doesn't matter to you, like for film, you could use a much less expensive indicator, or litmus paper or liquid Ph test or whatever.

I do agree that if you wait for the indicator to completely darken the bath is already way too neutralized. I dump it when I detect it going from yellowish to mostly clear.

 

[Photo Engineer]

It was also chosen because it washes out of films and papers totally. Some others are retained.

PE

 

[Gerald C Koch]

When you consider what the dye in ISB must do and not do the choice of indicator dyes is quite limited. I know because I have researched what is available. Bromcresol purple is really the only practical choice. But as AgX points out you could also use an indicator paper periodically. Litmus and congo red papers come to mind as the cheapest of these. Remember to buy the correct color one; blue for litmus and red for congo red paper.

 

[newcan1]

Boil a red cabbage and add the water to the vinegar?

 

[Gerald C Koch]

Jerry, what about bromcresol green? Probably a better indicator, although I have no idea what it costs, or if, as PE points out, it might react in other undesirable ways.

The pH and colors are OK. The only downside would be staining. You would have to test it. Personally I only use a stop bath for FB papers. I have found that the smell or removal of the slippery feel of the developer are just as accurate and cost nothing.

ISB is a marketer's dream. It appeals to people's gotta-have-this gut feeling rather than their really-need-this sensibility.

 

[Photo Engineer]

....
ISB is a marketer's dream. It appeals to people's gotta-have-this gut feeling rather than their really-need-this sensibility.

So are wash aids and hypo eliminators!

PE

 

[Roger Cole]

Huh? Everything I've read about fiber based print washing indicates that a wash aid is absolutely mandatory for a really good wash, no matter HOW long you wash without one.

Of course that's with regular acidic fixers. Maybe you mean to just use TF4 or 5 or the like?

 

[Roger Cole]

That's been the claim for decades but when I've read real tests on it, it didn't bear out, in particular the well known article "Secrets of the Vortex" or something like that in the old Camera and Darkroom. I still have those issues as well as scans of that article. Shrug. It's cheap. Mix your own from water and sulfite and it's even cheaper, almost free. I'll keep using it.

 

[Gerald C Koch]

Returning to the issue of stop baths. If you want to use white vinegar as a stop bath you must read the label. I have seen samples ranging from 4 to 5% acetic acid. There doesn't appear to be any standard concentration for the product.