Stop Bath.. How important?

[dancqu]

I've been developing using tap water instead of stopbath
and the results are fine, but someone told me the negative
keeps on developing unless i use stop bath.

An acid stop keeps an acid fix acidic. Do you use and
reuse an acid fixer?
Keeps on developing. Nothing more than a hint of water
bath development. Some go for it; two bath, the
B bath being water. Dan

 

[DannL]

I quit using stop bath with film several weeks ago. So far, so good. I just started "not using" with paper.

 

[JohnFinch]

As everyone has pointed out, there's no need for an acid stop bath unless your development times are very short <5 mins. If development times are short then you need to stop development very quickly and that would require the acid stop bath. However, most of us are developing for longer times than that.

I would not advise dropping the acid stop bath for printing paper though. It helps keep the highlights clean. I think this is possibly due to the fact that paper develops very quickly and the highlights will begin to dull with over development.

John
pictorialplanet.com

 

[Bob F.]

Others have answered, but from your question I suspect you might want to get a clearer idea of what is happening during processing so you can make up your own mind.

Developers are alkaline and development can only continue in an alkaline environment. Dunking the film in an acid stop bath (no more acidic than table vinegar, so no worries about that) rapidly changes the environment to acidic which stops development almost immediately.

Fixer is (usually) acidic. Using an acid stop bath prevents the alkaline developer from contaminating the fixer (which needs to be acidic to work). So, when using an acid fixer, the use of an acid stop bath both arrests development rapidly and extends the life of the fixer. Two good things in one!

Using water, the development is not stopped so suddenly, slowing development down until it eventually is effectively stopped as the water dilutes the developer soaked into the emulsion over a period of several seconds. Is this amount of extra development time important? Probably not in the great scheme of things given all the other variables. To avoid contaminating the fixer, a few changes of water with agitation will probably be required.

However, if you use a non-acidic fixer (not so common, but quite a few people prefer them) then you would probably use a few changes of water and not an acid stop as the acid would contaminate the alkaline, or neutral, fixer. All these fixers, both acid and alkaline, (and neutral) will have buffering agents to reduce the effects of this kind of contamination but they will last much longer if they are not contaminated in the first place.

If you do not like the smell of most stop baths, you can use a citric acid based stop (most are acetic acid - as in vinegar - based). Ilford (Ilfostop), Fotospeed and Tetenal amongst others make them. These have no odour at all. They work out somewhat more expensive I think, but that is a small price to pay for no odour IMNSHO .

Good luck, Bob.

 

[bessa_L_R3a]

that's a heck of a lot of feedback ... I'm developing HP5+ and time is 5 minutes (Dil B) at 68 F using Ilford rapid fixer and my wash is just 4 or 5 water refills with increasing agitation frequency with each fill.

i guess by using water stop bath i'm extending the developing time minimally from 5 minutes upwards but unless i'm doing anything radically wrong in all this i'll just do it this way.

 

[Paul Verizzo]

Hi,

I've been developing using tap water instead of stopbath and the results are fine, but someone told me the negative keeps on developing unless i use stop bath.

does it keep on developing even after it's been hung out to dry???

fyi: i am developing 35mm 400 iso BW film with HC -110

Robert.

"To manyworkers, the stop bath is merely a splash of acid in a vague amount of water. It should be compounded as directed." Ansel Adams

OTH, I'm sure that several water changes with agitation is equally effective and with minimal to no downstream, er, negatives. If it works, go for it. Remember, the bumblebee can't fly, either.

Kodak SB-6 Stop Bath: Sodium bisulfite 30 g, water to make one liter
Kodak SB-7 Stop Bath: Citric Acid 15 g, water to make 1 liter

The same baths with an "a" suffix are stronger for strong alkali developers. 37.5 grams of citric acid (not 37 or 38? :rolleyes or 75 grams of bisulfite.

Or, bottom line, 1/3 white vinegar, 2/3 water. Take that, Ansel!

All per Kodak.

 

[fschifano]

I quit using stop bath with film several weeks ago. So far, so good. I just started "not using" with paper.

Not using with paper is not such a good idea, even more so if you are using fiber based papers. I wouldn't worry so much about over development. That's pretty hard to do if you've exposed the paper correctly, since development is carried through to completion. The problems, veiled highlights etc., come about when some of the alkaline developer gets carried across to the acidic fixing bath. That's a sure way to cause staining and possibly some fogging of the highlights. You need to be extra cautious about washing the paper free of developer before its immersion into the fixing bath. That's tough to do in a tray without constantly changing water. The first couple of prints may work out OK, but after that the amount of developer carried over into the stop tray becomes significant enough to be of concern. If you have a sink in your darkroom, then you can use water rinse to your heart's content at the expense of a lot of wasted water. I don't see any advantage to this save the absence of the stop bath odor, which is not so bad if you've diluted your stop bath to the proper strength. It's only acetic acid at half the strength of table vinegar. If the odor of stop bath is bothersome, I'm willing to bet that the working solution is too strong.

 

[Steve Smith]

I use a stop bath with paper but not with film.

I only use a water stop bath with film if I plan on re-using the fixer. If the fixer is going to be discarded after use I just pour out the developer then pour in the fixer.



Steve.

 

[k_jupiter]

I use a stop bath with paper but not with film.

I only use a water stop bath with film if I plan on re-using the fixer. If the fixer is going to be discarded after use I just pour out the developer then pour in the fixer.



Steve.

Why would you discard the fixer after use?


tim in san jose

 

[Steve Smith]

Why would you discard the fixer after use?

Sorry, I should have been more specific - I said 'If the fixer is going to be discarded". It does not last forever.

If I am going to re-use the fix, I will use a water stop, if the fix is at the end of its useful life and is going to be discarded, I don't bother with the stop stage.



Steve.

 

[Snapshot]

I formally used an acidic stop bath with film but when I started to use staining developers, I went with a water bath. Thereafter, I used a water bath for all film and did not see a difference. However, my results are anecdotal and should be taken in that context.

 

[Deckled Edge]

Why would you discard the fixer after use?


tim in san jose

Tim,
Why would you NOT?

The fixer rapidly accumulates insoluable silver salts, which will eventually precipitate out onto the paper, and (being insoluable) cannot easily be washed away. That is why there are clear guidelines for the use of two fixer baths for archival prints, and why there are limits on how long you can use a finite amount of fixer.
I'm also a big fan of a dilute sodium sulfite bath after the fix, to re-dissolve those little salty buggers before the final archival wash.

 

[fhovie]

I used to be very anti stop bath and still am with film - I have had pin holes that were caused when the ph basic developer engaged the acid stop bath in the emulsion. Does development continue in a water bath? - absolutely - until it is exhausted. I know that exhaustion of developer in the emulsion could take as much as two minutes in a water bath - or longer. Is this important? I don't think so - I usually rinse my film for 2 or more minutes in a water bath before going to the fix. I do NOT use acid fixer - only ammonium thiosulfate based with a ph of about 8. I test my fixer with every use. My fixer TF3, can clear film in 30 seconds. At 45 seconds to one minute of clearing time, I chuck it for fresh. I did not do this in the early years and my legacy work shows it. This is the error that comes back to haunt you in 5 years or so. Keep your chems fresh.

I did go back to using stop bath in paper though. It is not so important with normal paper developers (Like PC-TEA or Dektol) but with Amidol based (staining) developers, I noticed staining when I only used a water stop. I get this stop bath mix from B&H photo - it smells like vanilla. It is inexpensive, it has a traditional indicator in it and I have had no staining issues with Amidol since using it. I also know that my fixer lasts longer and I can switch the lights on a little quicker to examine a print when I use stop bath. I do not know what is in it but it is nothing like acetic acid. - Likely something more like citric acid. I guess there are issues now in shipping acetic acid so traditional stop baths are less available for mail order sales.

http://www.bhphotovideo.com/c/product/50090-REG/Sprint_SB004_R_Block_Stop_Bath_for.html

I also use a fixer clearing agent - I do not do the two bath fix routine - but I make my first wash one with some sulfite in it.

 

[Bobby Ironsights]

I use a stop bath, and my reasons are pretty much covered by Bob's post on page one.

I'm not worried so much about the continuation of development while in the water bath. I am however, quite careful with my stop, as I use the (obsolete, yes I know) kodak powder fixer in the nice yellow/orange envelope, and it has limited capacity, and needs to be treated gently. An acid stop allows me to do this, and since I develop with the (yes I know, no imagination) divided D-76, I don't have any problems with pinholes as I might with any of the very exotic developers.

 

[DannL]

Not using with paper is not such a good idea, even more so if you are using fiber based papers. I wouldn't worry so much about over development. That's pretty hard to do if you've exposed the paper correctly, since development is carried through to completion. The problems, veiled highlights etc., come about when some of the alkaline developer gets carried across to the acidic fixing bath. That's a sure way to cause staining and possibly some fogging of the highlights. You need to be extra cautious about washing the paper free of developer before its immersion into the fixing bath. That's tough to do in a tray without constantly changing water. The first couple of prints may work out OK, but after that the amount of developer carried over into the stop tray becomes significant enough to be of concern. If you have a sink in your darkroom, then you can use water rinse to your heart's content at the expense of a lot of wasted water. I don't see any advantage to this save the absence of the stop bath odor, which is not so bad if you've diluted your stop bath to the proper strength. It's only acetic acid at half the strength of table vinegar. If the odor of stop bath is bothersome, I'm willing to bet that the working solution is too strong.

I trust my experimenting will be the cause for my ultimate demise.

 

[fhovie]

D-76 is the standard by which all developers are judged - and it is a tough standard to beat. But a few alternatives have some advantages, not all other choices have advantages, and the advantages are not huge. But some are worth noting.

You never need to be apologetic about using D-76 - It is a great brew and I keep it on hand for anytime I don't have something else better figured out. Your fixer on the other hand is likely the same composition that many of the greats produced their enduring classics with and is also a fine tool for use with D-76. If your materials make the art you like - they are great materials. Kind of like my paint can with a hole in it that I make panoramic photos with - simple or classic is not "better" or "worse" than "exotic" it is just an answer so good it has survived.

 

[k_jupiter]

Tim,
Why would you NOT?

The fixer rapidly accumulates insoluable silver salts, which will eventually precipitate out onto the paper, and (being insoluable) cannot easily be washed away. That is why there are clear guidelines for the use of two fixer baths for archival prints, and why there are limits on how long you can use a finite amount of fixer.
I'm also a big fan of a dilute sodium sulfite bath after the fix, to re-dissolve those little salty buggers before the final archival wash.

We were talking about film.

Paper is a totally different animal. I always use first fix and second fix for fiber prints. As well as a dilute toner for archival permanance.

But film? When the fix stops working, pour it into the recycle jug and make some more. But not a film before.

tim in san jose

 

[Photo Engineer]

Gentlemen;

The fixer rapidly accumulates SOLUABLE siver complexes! They do not precipitate out onto the paper or film if it has been stopped or rinsed in a bath prior to the fix to remove developer. They eventually accumulate to the point at which the fixer just stops working as it cannot dissolve insoluable silver salts from paper or film.

The very worst that can happen is when an alkaline piece of film or paper goes into an exhausted fix bath, then dichroic fog can form on the paper or film due to a sort of continued development (reduction of excess silver salts to silver metal) on the surface of the coating.

This is one reason why I suggest always using a stop bath. If a fixer is exhausted, you don't get dichroic fog and you don't ruin the picture as you can always refix in fresh fix as long as it has not been exposed to light.

One example of an exception is TF-4 which is formulated to prevent this situation. But, even here I use a stop.

PE

 

[Tom Hoskinson]

that's a heck of a lot of feedback ... I'm developing HP5+ and time is 5 minutes (Dil B) at 68 F using Ilford rapid fixer and my wash is just 4 or 5 water refills with increasing agitation frequency with each fill.

i guess by using water stop bath i'm extending the developing time minimally from 5 minutes upwards but unless i'm doing anything radically wrong in all this i'll just do it this way.

You may be extending deveolpment Minimally, however, since Ilford rapid fixer is an acid fixer....

 

[Snapshot]

One example of an exception is TF-4 which is formulated to prevent this situation. But, even here I use a stop.
PE

PE,

Is this due to its alkaline nature or is it solely because of the formula? Would TF-3 have similar benefits?

 

[Photo Engineer]

TF-4 is heavily buffered and therefore resists pH changes strongly. All I can say is that it performs well with an acid stop bath and does not smell as much of ammonia as when you just use a rinse. It is very well formulated.

PE

 

[Snapshot]

TF-4 is heavily buffered and therefore resists pH changes strongly. All I can say is that it performs well with an acid stop bath and does not smell as much of ammonia as when you just use a rinse. It is very well formulated.

PE

Thanks for the clarification PE.

 

[Deckled Edge]

Tim and PE
I stand corrected twice!
Thanks, Photo Engineer for once again untwisting my brain.

 

[Mahler_one]

Formulary TF 4 rapid fixer is a great product-quick, not much odor when made with distilled H20....The fact that fixing is quicker obviously makes archival washing easier because the shorter time in the fixer probably means less fixer to wash out. to be certain, I called PF to ask about stop bath ( on prints ) and they recommended NOT using stop bath because of reports of mottling and streaking with prints using TF4 AFTER astop bath. However, they do have stop both compatible with TF 4 rapid fixer for those who desire to continue to use a stop bath rather then water.

Ed

 

[dancqu]

... because the shorter time in the fixer
probably means less fixer to wash out. Ed

Not so much is it less fixer. It is less attachment
time for the fixer and it's silver complexes.

Also the less fix in the fixer the less water and time
to wash out. Currently I've been using a sodium
thiosulfate fixer at 1/16 normal strength to fix
Slavich paper. The fixer is used one-shot so
the silver load is below archival levels. A
hold/soak plus two soaks has the
paper clean. Dan