Stop Bath or Not?

[lonelyboy]

Do you use a stop bath in B/W processing? I did a test using stop bath vs tap water wash. Here is the comparison result:

http://blog.hmlai.com/2020/11/29/stop-bath-or-not/

 

[Bolo Kukus]

An interesting read from the OP but I think he has too much free time on his hands...

Some darkroom printers use water. Others go for brand name stop bath. A few dilute household vinegar until they figure out the absurd cost of doing this. A select few go the way of a citric acid stop bath.

Different strokes for different folks.

I bought a liter bottle of Kodak indicator stop bath (the smelly canary yellow concentrate) in 1990. A friend gave me his bottle, half full, in 2000 or 2001. I used to print a lot (still do but less often now) and I still have concentrate left in both bottles.

I worked out long ago that it works just as well diluted somewhat less than the recommended mix. At the of my printing session I just dispose of the chemistry anyway now.

Some good advice here, do NOT use the Kodak stop bath in your salad dressings...

I plan to leave whatever is left in the two bottles when I pop off this planet to my stepson, who is now keenly interested in photography and setting up his own darkroom.

 

[JP Owens]

Stopped using it decades ago. Water rinse is enough.

In my experience, the reaction between the stop bath and developer often blows holes in the emulsion of thin emulsion films like Pan-X.

 

[Bill Clark]

Using stop bath increases fixer life.

My process:

Developer
wash with water
stop bath
Rinse off stop bath
fixer
wash

Just what I do. Works for me.

 

[Benjamin Marks]

I think the OP's blog post says it all. Stop is not chemically necessary, but there is a bit of density difference between the mid-tones on his stop/no-stop comparison. This indicates to me that his negs continued a bit of density build up during the water-stop step. It is not much, but it is there. Slide the slider over the street in front of the big building in the mid-ground to see what I mean. In general, I think the most important thing is consistency, particularly the more film you process. Also, when I used a Jobo processor, there is a lot of surface area (tanks/reels) to carry over chems from one step to the next. I was typically developing 20 rolls of film at a time. In that case, you'd like your fixer to last as long as possible. With a single-reel metal tank though, you won't carry over more than a few mm of chemicals from one process step to another.

Another way to look at it: Stop bath is cheap, fixer is expensive. That was my rationale for my process.

BTW, to the points in the OP's blog post: Vinegar is acetic acid; table strength is about 5% if I recall correctly. And the bubbles the OP warns about only occur if your stop bath is waay too strong. Dilute table vinegar 1:3 and you'll be fine.

 

[valdas]

I only use it now in C41.

 

[narsuitus]

When I first started developing B&W film, I used an acetic acid stop bath between developer and fix.

When I started working for a newspaper, to save time, I stopped using a stop bath. My film went from developer directly to fix.

Today, I use a distilled water bath between developer and fix. I also prepare my developer and fix with distilled water. My final film wash is with distilled water. I do not use PhotoFlow.

 

[lonelyboy]

I think the OP's blog post says it all. Stop is not chemically necessary, but there is a bit of density difference between the mid-tones on his stop/no-stop comparison. This indicates to me that his negs continued a bit of density build up during the water-stop step. It is not much, but it is there. Slide the slider over the street in front of the big building in the mid-ground to see what I mean. In general, I think the most important thing is consistency, particularly the more film you process. Also, when I used a Jobo processor, there is a lot of surface area (tanks/reels) to carry over chems from one step to the next. I was typically developing 20 rolls of film at a time. In that case, you'd like your fixer to last as long as possible. With a single-reel metal tank though, you won't carry over more than a few mm of chemicals from one process step to another.

Another way to look at it: Stop bath is cheap, fixer is expensive. That was my rationale for my process.

BTW, to the points in the OP's blog post: Vinegar is acetic acid; table strength is about 5% if I recall correctly. And the bubbles the OP warns about only occur if your stop bath is waay too strong. Dilute table vinegar 1:3 and you'll be fine.

Exactly! This is what I mean.

A stop bath is necessary if you need to preserve the life of fixer. If you are just like me, processing several rolls a year and all solutions are one shot, then stop bath may not be necessary. The effect on picture quality in minimal.

 

[Hari]

Since I only develop one roll of 35mm or 120 at time,
water rinse is fine, plus I use Ilford rapid fix two
bath technic (after the first bath reaches the limit,
the second bath becomes first bath and mix a
fresh second bath). Cost is minor for small volumn.
In paper processing I use citric acid and the same
two bath fix.

 

[Prest_400]

The slight difference fellow forumers point about would be expected. I, and most of the other members at our photo club, do not use stop for developing.


My standard developer is HC110, usually quite diluted. I would imagine that with longer development times and diluted developer, water wash instead of stop will do fine. However, I usually wondered about this when developing with dilution B and 5-6 minutes time. A couple water changes take 15-30 seconds, and it can be a significant enough time with the residual developer.

As of fixer life, I should try to do a more scientific test. 1+4 for film, but I usually do not run more than 6 rolls (not a big shooter). Then, that fixer is spared and used for paper fixing instead, as a second lifecycle.


EDIT:

Exactly! This is what I mean.

A stop bath is necessary if you need to preserve the life of fixer. If you are just like me, processing several rolls a year and all solutions are one shot, then stop bath may not be necessary. The effect on picture quality in minimal.

Pretty much, I am a small batch developer too.


If anything, and as a quick edit afterthought, the life of fixer and its use is quite important with FB paper printing. Proper washing and use can be quite a complicated matter.

 

[Doug A]

Stop bath for paper. Water for film. Been doing it that way for 60+ years with no issues.

 

[css9450]

My standard developer is HC110, usually quite diluted. I would imagine that with longer development times and diluted developer, water wash instead of stop will do fine. However, I usually wondered about this when developing with dilution B and 5-6 minutes time.

I use a water bath as well, for the same reason. Rodinal in the bottle is highly concentrated but dilute it 50:1 and it's a fourteen minute developing time for Ilford Delta 100. To me, that's quite diluted and perfectly fine for water stop. I'd feel differently if it were 5-6 minutes.

Funny you mention HC-100 though. Yesterday, I finished an expired roll of Verichrome Pan and decided to give HC-110 a try. The only development time I could find for HC-110 was Dilution B at 4-1/4 minutes. That's crazy fast! In retrospect, perhaps I should have used a proper stop bath (or maybe a second water stop).

 

[KenR]

Pinholes

Pinholes

I was getting pinholes in my medium format negatives (never with 35mm) which some book (the best source of knowledge back in the dark ages) said was due to the stop bath. I switched to a water "stop bath" in between the developer and the fixer = problem solved. It has never happened again.

 

[KenR]

css9450 - when I get short times with HC110 dilution B, I dilute it further to a 1:63 dilution (so called dilution H) and cut the time in half. So a 4.5 minute time in dilution B becomes a much more manageable 9 minutes in dilution H.

 

[titrisol]

Not for film, yes for paper.

For film, 2 quick changes of water is plenty

For paper it is very important to obtain consistent results

 

[john_s]

Stop bath for paper. Water for film. Been doing it that way for 60+ years with no issues.

Same for me.


If you're using acidic stop only to avoid the small increase in pH of the fixer you're not achieving much if anything. I used to use Agfa FX-Universal C-41 fixer (pH=7.6) but now that it's unavailable I have to use a more acidic fixer (not many choices available in this part of the world) and add some hydroxide to bring its pH up a bit, to about pH=6 or 6.5. (This is for FB paper processing where washing is made easier if you use fixer that is less acidic). And I still use a mild acidic stop for FB paper because I have found that it prevents occasional staining.

 

[nikon_sam]

Stop bath for paper. Water for film. Been doing it that way for 60+ years with no issues.

I've done it this way for 45 years...
I reuse my Film Fixer until it stops doing its job within time limits
I toss Print Fixer after printing session...I never reuse it

 

[znapper]

Always use a good rinse with water, preferably 1-2 times, to get rid of as much developer as possible, before fixing.
Works fine.


I do use stop-baths when printing though, this is to preserve the fixer, mostly, but it sure is handy when Lith-printing.

 

[Ronald M]

I am low volume now that digital is here. However I got this advice from a wedding pro who did around 135 rolls a week during season. Use nothing. Develop , nothing, fix. It works, 2 steps. His prints were the envy of Chicago area wedding pros in 50`s and 60`s. He did kind of a semi stand with D76 & Plus X. He ordered 100 foot rolls of film from Kodak in multiple cases. It would last a year.

My experimentation shows a ss or water bath increases apparent grain if an undiluted developer is used, ie D76 stock.
I was never able to achieve his results using his instructions in 1980`s.

 

[Stuart John]

I stopped using stop bath with films. I just use a water rinse before the fixer. No reason other than I used to shoot and develop several films over a few weeks before I would start a printing session and it saved me having to mix up stop bath that I didn't need. I use my stop bath for prints as fibre based soaks up lots of dev and fixer wont last at all without stop.