Can I leave film in stop bath for 7 minutes?

[Richie]

My N-1, N, N+1 development times are (for simplicity) 5, 8, and 11 minutes. I use 4x5 film, hangers and tanks. I develop in a small bathroom. I don't have room to lay out all my tanks in a row at one time. My question is will it change the film to leave them in the stop bath for 7 minutes if I am developing an N-1 and an N+1 image in the same batch. My film development calibration is based on a stop bath of 1 minute.

I guess I could do a test: shoot a gray card for Zones I and VII for each of N-1, N, and N+1. Measure the densities and see if the long stop bath affected the N-1, or the N images. (I develop 6 sheets of film in a batch so I might as well throw in the 2 N+1 sheets, although none of the development has changed for them.)

[Jac@stafford.net]

Increase dilution and you should be okay. Strong stop bath can cause pin hole (gas bubbles) in the emulsion. A greater dilution used one-shot is best.
.

[Kevin Crisp]

Even very dilute stop bath is effective, I agree to weaken it, use good agitation when you put the film in initially, then use it one shot. Your film calibration shouldn't be thrown off at all by changes in time in the stop bath. It really does stop development, as anyone who has made the mistake of turning on the lights for a minute or two with film in the stop bath can tell you.

[Mark Sawyer]

Better to add the sheets at different times, the take them out together.

[Richie]

Thanks everyone for your help.

Mark, I was thinking that it would change the film more if I add the sheets at different times and take them out together because when I agitate for a minute when I add new films, the films just sitting there would get a little extra agitation, but maybe this little extra agitation changes the film less than the extra time in the diluted stop bath. What do others think is the lesser of the two evils?

[Jac@stafford.net]

Thanks everyone for your help.

Mark, I was thinking that it would change the film more if I add the sheets at different times and take them out together because when I agitate for a minute when I add new films, the films just sitting there would get a little extra agitation, but maybe this little extra agitation changes the film less than the extra time in the diluted stop bath. What do others think is the lesser of the two evils?

You need not agitate for one minute in stop bath. You are overdoing it but causing no harm - unless the time interferes with your workflow - the film still in the developer (N+).

[Kevin Crisp]

A couple sloshes of a tray stops development with even dilute stop bath. You don't need to give it a minute.

[Drew Wiley]

Some films are way more sensitive than others. Stop bath is traditionally 2% acetic. I find that this level of concentration is unnecessary, since I never reuse the
bath. The exact degree of dilution is not critical, but I mix it about a quarter that strength. Indicator stop bath is helpful; in that case, I dilute it to barely yellow.
And in predicaments like yours, leaving a few sheet a couple minutes longer in the stop, while still developing the remainder of the sheets, seems to have no ill
effect. But I am very careful to stack the code notches differently, and never develop odd lots in equal numbers where they might get confused.

[Luis-F-S]

Better to add the sheets at different times, then take them out together.

What I do! L

[lab black]

Although I have no experience regarding extending the stop bath processing time to seven minutes, I have found success, especially with Ilford films, utilizing the technique posted by Drew;

"The exact degree of dilution is not critical, but I mix it about a quarter that strength. Indicator stop bath is helpful; in that case, I dilute it to barely yellow."

[jp]

Depending on the developer and fixer choices, plain water could be an acceptable stop bath which would certainly be harmless to leave it in several minutes. Read the labels/instructions.

[stawastawa]

DO you have room to move them from the stop bath to a water holding bath?

[LabRat]

In general, getting the film into the fix ASAP is preferred as the film swells to it's max the thickness in the developer, shrinks a little while in SB, and much more in the hardening fixing bath, so the emulsion is in it's most fragile state after development, so best to keep it moving through the process... If you need a hold, better after the fix in wash water... It is wise to do separate runs for + or - processing as this will not create confusion while working in the dark (while multitasking)...

Steve K

[Greg]

Some films are way more sensitive than others. Stop bath is traditionally 2% acetic. I find that this level of concentration is unnecessary, since I never reuse the
bath. The exact degree of dilution is not critical, but I mix it about a quarter that strength. Indicator stop bath is helpful; in that case, I dilute it to barely yellow.
And in predicaments like yours, leaving a few sheet a couple minutes longer in the stop, while still developing the remainder of the sheets, seems to have no ill
effect. But I am very careful to stack the code notches differently, and never develop odd lots in equal numbers where they might get confused.

I also use a very diluted Kodak Indicator Stop Bath, probably less than 0.5% but at least triple the liquid volume of the developer. Have left films in it for very long times without ever having problems.

[Pere Casals]

My film development calibration is based on a stop bath of 1 minute.



Extended Stop Bath time has no impact in final result, if you calibrate your proces with 1 minute Stop Bath but later you use 5 minutes stop bath you won't see any difference.

Also it happens by extending fixing time. Once I forgot film inside fixer a night long and the next day I saw nothing different. Just check it.

There is a film that is damaged by extended fixer time: ADOX CMS 20, it is a very special film.



One thing else, after some 10 seconds of stop bath you can end the rest of the process lights open, you can also fix film under light, you'll see how fixer removes the "yellow" silver that has not reacted. If you look how BW reversal process (to obtain BW slides) is done you'll see that after bleaching you also do the rest under light.

Even with color Velvia / Provia / etc slides. Tetenal ColorTec E-6 development kit states in instructions that Steps "0-2 to be carried out in complete darkness" so steps 3 to 7 can be done lights open. I did it with perfect results.

See page 8, http://www.freestylephoto.biz/pdf/product_pdfs/tetenal/TetenalE6_Instructions.pdf



Stop Bath stops development, once the acid of the stop bath has stopped the development nothing happens, until you place film in the fixer, when fixer has removed the silver halide also nothing else happens.


Kodak TMax films need extended fixing time and agitation to remove a nasty pink cast in the negative (sensitizing dye) that extended fixing time do not damage the negative at all or change it, sometimes I fix TMax 20 minutes...

[Doremus Scudder]

Richie,

You don't say how you develop (although you do mention tanks). With tray processing, it's easy just to add sheets to the developer later. I routinely develop, say, N and N-1 together, adding the N-1 sheets a couple of minutes into the developing. My agitation is once through the stack every 30 seconds.

If you are developing film on hangers and doing dip and dunk with an initial longer agitation and then agitation every 30-60 seconds, it would seem easier to do as you suggest, i.e., let the film sit in the stop until the rest have finished developing. I can't see where an extended stop bath would do any damage at all. The pinholes mentioned above are not from extended time, but rather the formation of gas bubbles due to the reaction of an extremely alkaline developer with a strong stop (in which case, a weaker stop is indicated). If I were you, I'd simply go that route.

Although I can't imagine any damage from an extended stop bath and would not hesitate to try it myself if it seemed convenient, you should try it on a test sheet or two just in case.

Best,

Doremus

[Bob Salomon]

Extended Stop Bath time has no impact in final result, if you calibrate your proces with 1 minute Stop Bath but later you use 5 minutes stop bath you won't see any difference.

Also it happens by extending fixing time. Once I forgot film inside fixer a night long and the next day I saw nothing different. Just check it.

There is a film that is damaged by extended fixer time: ADOX CMS 20, it is a very special film.



One thing else, after some 10 seconds of stop bath you can end the rest of the process lights open, you can also fix film under light, you'll see how fixer removes the "yellow" silver that has not reacted. If you look how BW reversal process (to obtain BW slides) is done you'll see that after bleaching you also do the rest under light.

Even with color Velvia / Provia / etc slides. Tetenal ColorTec E-6 development kit states in instructions that Steps "0-2 to be carried out in complete darkness" so steps 3 to 7 can be done lights open. I did it with perfect results.

See page 8, http://www.freestylephoto.biz/pdf/product_pdfs/tetenal/TetenalE6_Instructions.pdf

Film grain increases with the length of the film's wet time. So yes, there is a difference. Each wet step should be at the recommended times unless you are purposely extending the ISO or reducing the ISO.

Stop Bath stops development, once the acid of the stop bath has stopped the development nothing happens, until you place film in the fixer, when fixer has removed the silver halide also nothing else happens.


Kodak TMax films need extended fixing time and agitation to remove a nasty pink cast in the negative (sensitizing dye) that extended fixing time do not damage the negative at all or change it, sometimes I fix TMax 20 minutes...

[plaubel]

Extended Stop Bath time has no impact in final result,
Also it happens by extending fixing time. .

My experience is completely different, so in general I would love to say the opposite.

For example, I have had blank film after only 6 minutes fixing them, so it depends on material.
Thin layer films seem to be very sensitive, but others may react, too.

Paper changes tonality after long stopbath sessions, so I would expect something simular with negatives, but this experience describes stopping of 15 or 30 minutes, not only seven minutes.


""One thing else, after some 10 seconds of stop bath you can end the rest of the process lights open""

Not only that 10 seconds are less than recommended; light will do something to your material.
Because I am lazy, I have done some experiments, and if I want to work fast with test stripes, I open the light after 30 seconds of stopping, yes.
But they change smooth, and they continue to change.
Again 15 to 30 minutes later, I alwaysh get a radically but somehow interesting change,like toning the welldone print..

No, I woudn't do this with my negatives, and imo bleaching of slides is not comparable with developing and stopping negatives.
Every process that I am aware could be done in light, after bleaching.
Every of my good negatives don't see light until they are complety fixed.


Ritchie

[Pere Casals]

My experience is completely different, so in general I would love to say the opposite.

For example, I have had blank film after only 6 minutes fixing them, so it depends on material.
Thin layer films seem to be very sensitive, but others may react, too.

Paper changes tonality after long stopbath sessions, so I would expect something simular with negatives, but this experience describes stopping of 15 or 30 minutes, not only seven minutes.


""One thing else, after some 10 seconds of stop bath you can end the rest of the process lights open""

Not only that 10 seconds are less than recommended; light will do something to your material.
Because I am lazy, I have done some experiments, and if I want to work fast with test stripes, I open the light after 30 seconds of stopping, yes.
But they change smooth, and they continue to change.
Again 15 to 30 minutes later, I alwaysh get a radically but somehow interesting change,like toning the welldone print..

No, I woudn't do this with my negatives, and imo bleaching of slides is not comparable with developing and stopping negatives.
Every process that I am aware could be done in light, after bleaching.
Every of my good negatives don't see light until they are complety fixed.


Ritchie


Hello Ritchie,

I'm happy to share experiences with you.


Film and paper cannot be commpared directly. Paper is ISO 1 or 2. Adox CMS 20 is ISO 6 nominal, normally shot at 12 or 20, but grain is much smaller, this is the single film that I found sensitive to extending fixing time.

There are some films from china and eastern block that are not advanced, with delicate emulsions, that even need hardener...

But "Occidental" films, all from ilford, kodak and the like are in another league.

In fact TMax films need 4x fixing extended time, not to fix the halide, but to remove the pink dye(sensitization). That extended required time did not worried Kodak at all. And Tmax also has small grains...

Still this is something one may test. It costs one sheet. Just take two shot and leave one fixing all night long. Then compare.




Fixing lights open

Once film emulsion becomes acid in the stop bath the developer activity is completely stoped. No more halide reacts fo form metallic silver. Any reaction is very, very slow. Also one can test that with real film. It also costs a sheet. Just leave a sheet all night long in the Stop bath lights open...

I said 10 seconds in stop bath before opening lights but it can be less or a bit more. With 10 seconds I do not notice any increase in base+fog, checked with a high precission densitometer.


There is a test that will show something. Lights open take a film end, this is completely exposed. Don't develop it. Directly place it directly in the stop bath what time you like, say 5 min. Fix it also under light. You'll obtain a clear strip. Then check base+fog, you have to see the same than with dark procedure.

I made those tests because I develop 8x10 sheets in trays to better control agitation, and it is very useful to make rest of process under light. Also I see how fast it is fixed, so I know when fixer gets exhausted.


Doing it in darkness if ok, but if you want to know if it is necessary, this has a cost of two sheets.

[Doremus Scudder]

A couple of observations about best practice:

First, overfixing film or paper is not a good idea. Pere, you might have been able to get away with leaving a negative in the fixer overnight, but I'm willing to bet that the shadows bleached a tiny bit (especially if you use a rapid fix). That said, film and RC paper don't have the problem of fixer soaking into the paper base and can be fixed longer than the minimum needed for full fixation without any problems up to the point where bleaching starts to be a problem. I, like Pere and many others, fix T-Max films for substantially longer than needed to better remove the pink dye. Where does bleaching start to be a problem? That depends on your negative and the type and dilution of fixer you use. An overexposed neg might even benefit from a little bleaching... However, wet time should be kept to a minimum. Holding film in any fluid for hours risks damaging the emulsion.

Plaubel, I'm not sure what you mean about getting "blank film" after six minutes of fixing. If you're saying that six minutes in the fix completely bleached away the image, I think you may be mistaken. The most aggressive fixers I know don't bleach appreciably until much, much longer than that. I also don't know what you mean by paper changing "tonality" after "long stopbath sessions." I can imagine some papers, especially fiber-base papers, becoming stained by the indicator in the stop bath, making the whites yellower. As for the silver image, I simply can't imagine that a weak acetic or citric acid solution is going to affect it in any way, even with very extended exposure.

As for "lights on" after the film/paper is in the acid stop for a few seconds. Two things happen here. First, as Pere notes, the development activity has been effectively halted, meaning that if the fixer is acid as well, you could flip on the light after a few seconds in the stop and do the rest of the processing in room light (watching the film/paper clear in the fix is informative and fun). There are some caveats here, however. Many materials, notably papers, will "print out" with exposure to light after some time. If the light source is strong enough and the fixing step is slow enough, you can fog papers and films by doing this. If you use an alkaline fixer, any developer carried over after the stop step will be reactivated in the alkaline environment. If you've turned on the lights during the stop step, you've just exposed the rest of the paper/film and it will begin to develop again in the alkaline fix, fogging and streaking it till whatever developer left in the emulsion is exhausted. Don't ask me how I know this :)

Best practice is to leave the white lights off until the film/paper has been in the fix for half the total fixing time. You can get away with less, but it's not best practice and, with papers, you can fog the whites. Film is less susceptible to this effect, so you may see no difference in fb+f when using acid stop and fix. Pere, if you've tested your workflow with a precision densitometer, then there's no reason not to complete the last film-developing steps with the light on. I would never do that with a print, however.

Back to the purpose of this thread: If the OP stops some film sheets before others and lets them sit in the stop bath while the others finish developing, there should be no ill effects. Again, I simply can't imagine any damage to the image from a few extra minutes in a weak acid solution. Testing this workflow is easy, so should be simple to confirm or refute.

Best,

Doremus

[Pere Casals]

A couple of observations about best practice:

First, overfixing film or paper is not a good idea. Pere, you might have been able to get away with leaving a negative in the fixer overnight, but I'm willing to bet that the shadows bleached a tiny bit (especially if you use a rapid fix). That said, film and RC paper don't have the problem of fixer soaking into the paper base and can be fixed longer than the minimum needed for full fixation without any problems up to the point where bleaching starts to be a problem. I, like Pere and many others, fix T-Max films for substantially longer than needed to better remove the pink dye. Where does bleaching start to be a problem? That depends on your negative and the type and dilution of fixer you use. An overexposed neg might even benefit from a little bleaching... However, wet time should be kept to a minimum. Holding film in any fluid for hours risks damaging the emulsion.

Plaubel, I'm not sure what you mean about getting "blank film" after six minutes of fixing. If you're saying that six minutes in the fix completely bleached away the image, I think you may be mistaken. The most aggressive fixers I know don't bleach appreciably until much, much longer than that. I also don't know what you mean by paper changing "tonality" after "long stopbath sessions." I can imagine some papers, especially fiber-base papers, becoming stained by the indicator in the stop bath, making the whites yellower. As for the silver image, I simply can't imagine that a weak acetic or citric acid solution is going to affect it in any way, even with very extended exposure.

As for "lights on" after the film/paper is in the acid stop for a few seconds. Two things happen here. First, as Pere notes, the development activity has been effectively halted, meaning that if the fixer is acid as well, you could flip on the light after a few seconds in the stop and do the rest of the processing in room light (watching the film/paper clear in the fix is informative and fun). There are some caveats here, however. Many materials, notably papers, will "print out" with exposure to light after some time. If the light source is strong enough and the fixing step is slow enough, you can fog papers and films by doing this. If you use an alkaline fixer, any developer carried over after the stop step will be reactivated in the alkaline environment. If you've turned on the lights during the stop step, you've just exposed the rest of the paper/film and it will begin to develop again in the alkaline fix, fogging and streaking it till whatever developer left in the emulsion is exhausted. Don't ask me how I know this :)

Best practice is to leave the white lights off until the film/paper has been in the fix for half the total fixing time. You can get away with less, but it's not best practice and, with papers, you can fog the whites. Film is less susceptible to this effect, so you may see no difference in fb+f when using acid stop and fix. Pere, if you've tested your workflow with a precision densitometer, then there's no reason not to complete the last film-developing steps with the light on. I would never do that with a print, however.

Back to the purpose of this thread: If the OP stops some film sheets before others and lets them sit in the stop bath while the others finish developing, there should be no ill effects. Again, I simply can't imagine any damage to the image from a few extra minutes in a weak acid solution. Testing this workflow is easy, so should be simple to confirm or refute.

Best,

Doremus


Thanks for that information. It is allways great to learn from masters.

I was aware of possible bleaching effect with very low ISO film CMS 20, warns about it. I think it can be interesting to know at what point tiny bleaching effect of overfixing can be seen. Now I'm learning to calibrate film/paper and I'm to complete extensive tests, so I'll include overfixing some contact copies of the stouffer gauge in order to measure this effect with precission.


About paper, I think I remember (not sure, I can be well mistaken) that paper emulsion may contain hydroquinone as a preservative, that of course do not work as a developer until in wet alkaline medium...

Perhaps that deep hydroquinone remains in paper until fixing or washing, and it gets active again if fixer is alkaline. Just guessing...

With film, my informal tests showed me that film can be fixed lights on with no side effect. Still I'll check it well with a contact print of the Stouffer !

[Sirius Glass]

Stop bath is only needed for 30 seconds to a minute. After that move it to a water bath and let it sit or use a diluted stop bath.

[plaubel]

Doing it in darkness if ok, but if you want to know if it is necessary, this has a cost of two sheets.

Peter, I'm absolutely sure that your technique works with your materials, but after making other experiences myself, I further would not say that light on is a good idea in general.
Seems to depend on different circumstances and the material in use, like you described with Adox 20.


Doremus, some years ago fixing my film with usual times like 6 or 7 minutes ( an eastern film from russia called Tasma, a technical film), I have had problems; the film didn't become totally blank, but I was able to wipe the emulsion with my fingers.
After discussing this problem with an experienced guy, Mr. Coffenol, it was clear to me that thin layer film needs less fixing time - and then it worked well.
This showed me something, and as you have said before, in using chemicals I try to hold the recommended times.

"" I also don't know what you mean by paper changing "tonality" after "long stopbath sessions." ""

It's easier to me to bring a real example than describing in english, so please let me bring an example next days :-)

"" Just leave a sheet all night long in the Stop bath lights open...""

I love science, so I will do this together with the paper longstopping.

Best,
Ritchie

[plaubel]

After rereading, I have to add that I don't use an acid fix, and I want to note that I use citrus acid for stopping processes.
Ritchie

[Doremus Scudder]

After rereading, I have to add that I don't use an acid fix, and I want to note that I use citrus acid for stopping processes.
Ritchie

Ritchie,

You likely don't want to expose your film to light until well into the fixing process then. It would almost certainly fog it due to carried-over developer reactivating in an alkaline fix. Many don't realize that developer chemicals don't get washed out in the stop, just neutralized and will come back to life in an alkaline environment.

Doremus

[Mrportr8]

I add film to the developer at different times so they all come out at the same time. It simplifies everything else. To the rest of you, whatever works. The important thing is the end result and if you're satisfied.

[Pere Casals]

Ritchie,

You likely don't want to expose your film to light until well into the fixing process then. It would almost certainly fog it due to carried-over developer reactivating in an alkaline fix. Many don't realize that developer chemicals don't get washed out in the stop, just neutralized and will come back to life in an alkaline environment.

Doremus

Doremus, if sinking the paper in developer by using the clamps that are in the stop bath it happens that those areas that got in contact with the stop liquid do not develop at all, delivering perfect white stains.

From this, I looks to me than contact with stop bath prevents than any development can take place after. Perhaps a test may be made...

Pere

[plaubel]

Ritchie,

You likely don't want to expose your film to light until well into the fixing process then.

Thanks, Doremus.
That's exactly what I have told before, but probably for other reasons.
Exposing after a 10 second stopbath may not function in any case.

Usually developing, stopping and fixing in darkness, I haven't seen the reactivation of silver under light and in alcaline fix, weither in the dark nor in my experiments, so I have to lighten the scene next.

I know that the acid of the stopbath is only a stopping agent, which does not protect the silver.
Fixing will wash out the remaining silver, but during this process there come out some new chemicals.
That's the reason for doubling the clearence time - we want to wash out this new products, too.

Tomorrow I will enter my darkroom with an uncommon todo list...

Best,
Ritchie

[Pere Casals]

Thanks, Doremus.
That's exactly what I have told before, but probably for other reasons.
Exposing after a 10 second stopbath may not function in any case.

Usually developing, stopping and fixing in darkness, I haven't seen the reactivation of silver under light and in alcaline fix, weither in the dark nor in my experiments, so I have to lighten the scene next.

I know that the acid of the stopbath is only a stopping agent, which does not protect the silver.
Fixing will wash out the remaining silver, but during this process there come out some new chemicals.
That's the reason for doubling the clearence time - we want to wash out this new products, too.

Tomorrow I will enter my darkroom with an uncommon todo list...

Best,
Ritchie

Just a quote from Roger Hicks, "British author of more than 30 photography books" (http://www.rogerandfrances.com/)

He says:

"You can transfer the film from a tank of dev to the fix tank by room light.
The few seconds exposure as you pull the film out of the developer and drop it into the fixer tank will not cause detectable fogging, because the induction period of the second development is longer than the time available"

Anyway this is something way easy to test.

Also we can test the practical induction time, this is taking a film end, with lights open, then introducing the film in the developer in steps of 5 seconds, and then stop+fix. At some developing time step some fog will appear.

Regards

[LabRat]

Just a quote from Roger Hicks, "British author of more than 30 photography books" (http://www.rogerandfrances.com/)

He says:

"You can transfer the film from a tank of dev to the fix tank by room light.
The few seconds exposure as you pull the film out of the developer and drop it into the fixer tank will not cause detectable fogging, because the induction period of the second development is longer than the time available"

Anyway this is something way easy to test.

Also we can test the practical induction time, this is taking a film end, with lights open, then introducing the film in the developer in steps of 5 seconds, and then stop+fix. At some developing time step some fog will appear.

Regards

I don't exactly know the fact or science of this, but when clearing a lot of old film in fix while in roomlight, one thing I have observed is that film cleared in the dark tends to clear a little faster and clearer (without the slight pink cast, that is from a trace of finely divided silver left on the material), and even with the accepted practice of turning the lights on halfway through the fixing stage, it seems to clear better/faster in the dark, so it seems that exposed free silver is a little harder/more stubborn to fully clear in my rapid fix IMHO...

Steve K

[koraks]

He says:

"You can transfer the film from a tank of dev to the fix tank by room light.
The few seconds exposure as you pull the film out of the developer and drop it into the fixer tank will not cause detectable fogging, because the induction period of the second development is longer than the time available"

Be that as it may, I have found that particularly x-ray film will fog severely if the light is turned on before it is entirely fixed. While Roger's advice may be sound for regular films, I wouldn't gamble with it.

[Pere Casals]

I don't exactly know the fact or science of this, but when clearing a lot of old film in fix while in roomlight, one thing I have observed is that film cleared in the dark tends to clear a little faster and clearer (without the slight pink cast, that is from a trace of finely divided silver left on the material), and even with the accepted practice of turning the lights on halfway through the fixing stage, it seems to clear better/faster in the dark, so it seems that exposed free silver is a little harder/more stubborn to fully clear in my rapid fix IMHO...

Steve K


I'll test that... it is an interesting point. Of course exposed grains (+ charged) have a selective chemical tendence to go metallic with developers, so a weak fixer may take more time. I guess that it may depend on the type of fixer...


Perhaps even having a base+fog of 0.11D is the same than 0.10D to obtain the same print, anyway it is very easy to test if additional fog is added, I'll do it... as I develop 8x10 in tray (paper safe) it is very convenient to open lights ASAP.

I guess that best test is to take an unexposed film end, fixing half in darkness and the other half lights open, and then measuring both with a precission densitometer.