Stop Bath.. How important?

[blockend]

Albert Ainstein?

Anselholics Anonymous

 

[NB23]

No - the stop bath prevents that.
The advantage is that you can turn on the lights and actually start seeing what you are doing once the stop bath has done its job.

you can always continue to develop

 

[MattKing]

How effective would a water stop bath be after Pyrocat-DH development -- good enough for the lights, or wait until the film hits the fixer? (open trays, 11x14 film) Thx...

PS...I remember AA recommending somewhere to make sure the stop bath was used at its full normal working strength (for prints).

I wouldn't do this with a water stop. A very small amount of development probably continues for a short while even after the film is in the fixer.

 

[Vaughn]

Thanks -- that is what I thought the answer would be -- I do not even turn lights on until totally fixed. Old habits are difficult to get rid of. But there's hope.

 

[138S]

Bad idea, Vaughn. Remember that a water stop bath works relatively slowly by simply diluting/washing the developer out, not chemically stopping the developer. Development does not stop immediately. So if the lights are on, exposing the film or paper, while development is slowing down but still happening...

From The Darkroom Cookbook:

Personally I always develop BW film sheets in trays (in a paper safe), when development done I close lights to move the sheet to a tray with plain water and after 30 seconds I open lights, then I fix also with lights open. I've tested it well and absolutelly no detectable fogging is produced. I tested it by developing unexposed samples, comparing opening lights after 30 seconds in the water bath to case it was all done in darkness.

Well, this is something quite easy to check at home, we only need an unexposed film end, just we can cut the stretch between the reel and the shutter window, that part is not exposed.

With paper it is different, if fixer is alkaline then development of the newly exposed crystals may start in it... at least it happened to me. But with film I never had a problem.

 

[Don_ih]

Stop bath neutralizes the alkalinity of the developer that is on the film or paper. It stops development, causes the emulsion to harden somewhat, and helps preserve the acidity of hardening fix baths. I use TF-3 fixer, which is non-hardening and alkaline. I don't want any acid on prints, so I don't use stop bath, just water.

 

[radiant]

There are a lot of people who find it difficult to handle film in total darkness without daylight tanks. This cuts down on the difficulty.

And cuts down 5-10 minutes that you need to spend in total darkness

 

[MattKing]

Same here. Seems like a pretty needless risk but that’s just my own two cents. On the other hand I don’t know of any darkroom workers who purposely turn the lights on at the stop stage either. Did Kodak or Ilford ever recommend it?

I don't know about Kodak or Ilford, but Phil Davis certainly did - it is standard procedure with BTZS tubes.

 

[Vaughn]

We have members that turn lights on during stop bath it seems without issues. There are some development systems that take it into account and do not worry about light exposure after stop bath.

For me, one step at a time. I'll be developing some 11x14 tonight -- I'll turn my yellow safe light on (60W bug light) after the film hits the fix (the room white light switch is on the other side of the door). I think I can do it.

To turn the light on after a water stop (non-running) would be handy as I need to move stuff around to get the film into the fix tray. Even a 10W light under the sink would be enough with my eyes already use to the dark...but that will have to wait for when I use a non-pyro developer and an acidic stop bath...might give it a test then.

 

[Sirius Glass]

... and besides Stop Bath with Indicator is just so damned expensive!

 

[Lachlan Young]

Bad idea, Vaughn. Remember that a water stop bath works relatively slowly by simply diluting/washing the developer out, not chemically stopping the developer. Development does not stop immediately. So if the lights are on, exposing the film or paper, while development is slowing down but still happening...

I suspect that most of the claims around a water rinse between developer and fix come from those who use developers that are very nearly exhausted at the end of the processing time - it's a claim that always seems to go hand in hand with special pleading about silver-bullet developers... As opposed to most stop baths which will slam things to a halt in 10 seconds. There is an inductance period after processing which may be what's letting people get away with the stupendously bad technique of putting the lights on while the film hasn't been stopped/ fixed, but an awful lot of the anti stop bath propaganda seems to derive from a major lack of knowledge about film hardening in the last 60-70 years (helped along by the usual woefully wrong books).

 

[138S]

Michael, also we have induction time... when opening lights newly exposed crystals don't develop inmediately, induction time has to pass, even if we open lights prematurely (development not stopped yet) nothing will happen because when induction time has passed then development will be well stopped.

Again, this is something it can be checked very easily, just processing unexposed film samples and comparing, nothing like testing simple things.

 

[MattKing]

The issue isn't light exposure. It is developer carry-over.
The exposure doesn't matter if there aren't any reducing agents left in the mix. Subsequently exposed silver halides will just get fixed away without effect.
Assuming of course that the light exposure isn't so long and intense as to cause printing out.

 

[138S]

The issue isn't light exposure. It is developer carry-over.
The exposure doesn't matter if there aren't any reducing agents left in the mix. Subsequently exposed silver halides will just get fixed away without effect.
Assuming of course that the light exposure isn't so long and intense as to cause printing out.

OK, but emulsion may not be well washed when opening lights... what I say is that induction time works like a safety belt: Even in the case we open lights before development is totally stopped no harm will be produced, because the newly exposed crystals won't develop for the induction period, so when the crystals would develop the development is to be arrested anyway.

 

[Vaughn]

I have friends who will not drive off in the morning until the auto-choke (or functional equivilent these days) kicks off. I start the engine and by the time I put my belt on, check the mirrors, the engine has revolved a couple thousand times minimum and off I go. So whose engine will last longer if they use an acidic stop bath first?

 

[138S]

Obviously there is induction time - which is yet another variable not known by the user. I'm sorry but this is just a potential risk/problem for no particular reason. It's a darkroom. You've developed in the dark, which is the majority of the time. You can't wait an extra 30 seconds for the stop bath and maybe 1-2 minutes for preliminary fixing? And even if you absolutely can't wait, it has to be full room lights on?

Michael, I don't develop in the dark, I place the (8x10") sheet in a 8x10" paper safe, so in fact I have a daylight processor, I only close lights to move the sheet to the water bath (or acid bath), and after 30s seconds I open lights to prepare development for the next sheet (dumping and pouring fresh one shot developer) washing hands well and preparing the holder. Then I close lights to deep the new sheet in the day-light-tray and open lights again to work the fixing/washing/drying the sheets, in that way I tray-process around six 8x10" sheets in an hour, each at different N+/- if necesaary.

Thay way is quite faster than the expert drum when more than a single N grade is necessary, having the benefit of adjustable agitation to provide some compensation.

Could I wait more than 30 seconds to open light after the sheet is in the stop ? Of course !! but I found that 30 seconds is safe, and I checked it well because I value a lot the effort invested in a 8x10 sheet.

 

[cliveh]

I would suggest that if you take a print or film from and alkali solution and then put it in a near neutral pH solution (water) and then turn on the lights you may introduce a level of fog. This maybe not visible to the eye, but could raise base fog. Has anyone tested this by experimenting lights before and after fix using a densitometer?

 

[138S]

So whose engine will last longer if they use an acidic stop bath first?

Vaughn, let me tell why I use water instead acid... if you read my workflow in my previous post, I have the stop tray at the side of the daylight developer tray... any spill of stop bath or drops on the table can contaminate my hands, so when manipulating the next sheet there is the potential risk I contaminate the sheet leaving not developed marks, it happened me. With stop water that risk is not there...

I only operate the fixer tray lights open, and tht tray is farther, so even in the case fixer is acid risk is small.

 

[138S]

I would suggest that if you take a print or film from and alkali solution and then put it in a near neutral pH solution (water) and then turn on the lights you may introduce a level of fog. This maybe not visible to the eye, but could raise base fog. Has anyone tested this by experimenting lights before and after fix using a densitometer?

Yes with a print, not with film. Modern Photopaper usually includes hydroquinone in the emulsion... it is a different situation. Still... test it ! I've tested it well with a densitometer

 

[Vaughn]

Using pyro developers, I unload a sheet out of the 11x14 holder behind me with one hand wearing a glove. I can't grab the sheet out of the holder with a gloved hand...need my fingernails. I set the film on top of the holder, get the other glove on, grab the film and into either a water bath or straight into the developer, depending on how I am feeling. When using Ilford Universal PQ developer, I might skip the gloves. Then a water stop for the pyro developer and an acid bath for the PQ developer.

I like an acid bath with the PQ developer...kinda of nice to know I have neutralized the base completely and my fingers are not slippery anymore.

 

[Sirius Glass]

Using pyro developers, I unload a sheet out of the 11x14 holder behind me with one hand wearing a glove. I can't grab the sheet out of the holder with a gloved hand...need my fingernails. I set the film on top of the holder, get the other glove on, grab the film and into either a water bath or straight into the developer, depending on how I am feeling. When using Ilford Universal PQ developer, I might skip the gloves. Then a water stop for the pyro developer and an acid bath for the PQ developer.

I like an acid bath with the PQ developer...kinda of nice to know I have neutralized the base completely and my fingers are not slippery anymore.

Pyro developers are the one place that I agree stop bath is not needed.

 

[138S]

Using pyro developers, I unload a sheet out of the 11x14 holder behind me with one hand wearing a glove.

You may try using a 11x14 paper safe !





IMO this Premier model of is lower quality and bottom is not perfectly flat, I have one like that, I ended gluing a plating in the bottom external side to make it flat...

Developing in a daylight tray is like riding an electrically assited bike !

 

[MattKing]

Obviously there is induction time - which is yet another variable not known by the user. I'm sorry but this is just a potential risk/problem for no particular reason. It's a darkroom. You've developed in the dark, which is the majority of the time. You can't wait an extra 30 seconds for the stop bath and maybe 1-2 minutes for preliminary fixing? And even if you absolutely can't wait, it has to be full room lights on?

FWIW, I don't open my daylight tanks until I am at least half way through fixing, and usually not until the end of the fixing stage.
But I would definitely do things differently if I needed to be pouring chemicals or moving sheets from tray to tray in absolute darkness.
Particularly if I was working in a tiny space.

 

[MattKing]

If there is no other way (BTZS for example), I guess you have to, but sheet/tray development - I'm not buying that one. Gathering the sheets and transferring to the stop bath, then doing the same to transfer to the fixer, that's just part of tray development of sheet film. Small space, tiny space. I'd honestly never before heard of anyone purposely turning the lights on before at least partial fixation, but that was before this thread...

You probably have two hands that are capable of handling sheet film. I'm limited to one plus a non-dexterous second.
Just to highlight the fact that different people have different circumstances.

 

[cliveh]

Did Edward Weston use water as a stop bath? Name me any top world gelatin silver printer who uses water as a stop bath?