Stop Bath.. How important?

[SchwinnParamount]

Water Vs. stop bath and film development

In the last couple of months, I've seen odd density variations in my Plus-X and FP4+. On the long edges of each frame is a subtle area of increased density which runs the lenght of the frame.

I develop in a steel tank with steel reels of course. For the last couple of years I've been using water as a stop bath as I was told I risk pinholes in the film when using stop bath of too strong a concentration. Rather than determining the correct concentration, I switched to water as it is 'supposedly' as effective as stop bath.

I switched back to stop bath for my most recent roll of film and the density problem also disappeared. There were no other process changes. Is it possible that a water stop bath is less effective in stopping development at the edges of the film where it is in contact with the reels?

 

[df cardwell]

Is this sheet film or roll film ?
What developer ?
Fixer ?

I think your hypothesis could be right, but it would help to complete the picture with your other variables.

Think we can put together an APUG PBP team in 2007 ?

.

 

[reellis67]

I always use a water stop and have never seen what you are describing. I use Ilford films (120 and 35mm), various developers (diafine, Microdol-X, Rodinal) and TF-4 fixer on steel reels/tanks. The only thing different about a water stop is that a small amount of developer remains active for a short time which increases adjacency effects slightly. Since my development times are always long, I suppose it makes no noticeable difference. How long are your development times?

- Randy

 

[Loose Gravel]

I don't think it is the stop bath. I had problems with steel reels giving increased edge density. (Surge) I don't know for a fact, but I believe that the round reels allow eddies to form and provide increased agitation. Different types of agitation may change this, but I went to Paterson tanks and have never had the problems since.

Oh yes, I have always used just water, never stop bath.

 

[SchwinnParamount]

Is this sheet film or roll film ?
What developer ?
Fixer ?

I think your hypothesis could be right, but it would help to complete the picture with your other variables.

Think we can put together an APUG PBP team in 2007 ?

.

I am developing 35mm film in XTOL and the fixer is a standard hardening fixer made by a local company.

 

[Claire Senft]

For a stopbath one does not need to use a strong solution. Vinegar 1:4 in tap water is pretty mild 1:8 should work well also...certainly, I believe it would be more effective than water. You could also try a 2% solution of sodium bisulphite.

I would guess that the shorter the development time the more precision is aided by a stop bath. For instance to get predictible results with say Pan F+ in a developer at 5 minutes in a Rodinal solution compared to Delta 100 stand development of 45 minutes in Pyrocat HD solution the stopbath might be more helpful in controlling contrast variations when the time is short than when it is a great deal longer. In either case stopbath should be helpful in preventing stains etc.

 

[psvensson]

How do you agitate? Do you agitate the stop bath?

 

[df cardwell]

I don't see the stop bath / water bath being a factor.

It isn't in the water bath that long, and these films fix quickly.

If it went away in the acid stop, stick with it. If it comes back, it wasn't the stop bath--- if it never comes back, it MIGHT be the acid stop.. but it doesn't really matter.

.

 

[dancqu]

Is it possible that a water stop bath is less effective in
stopping development at the edges of the film where it
is in contact with the reels?

My tap water is as alkaline as some developers I've used.

More often that is a problem of the developing process
and proper agitation. With a water stop, dilution of
the developer and ph reduction are very swift.

I've stopped using stops of any sort. Instead I use
very dilute unadulterated sodium or ammonium
thiosulfate. The two have a near neutral ph.

 

[Ronald Moravec]

Oh another one who thinks surge marks exist. They don`t. They are simply areas that received the proper agitation compared to the areas that that did not so they are under developed. The usual cure is to try less and more gentle agitation. Guess what, the surge marks get worse.

The reason the Patterson tanks works well is there is lots of free space for the developer to flow into while inverting providing full and complete agitation.

Put only enough developer in the stainless tank to cover the reel fully and invert 5 to 7 times in 5 sec twice a minute. You want the developer to move and replace all the used developer across the full film surface. This is right off Kodaks website.
You may also use a two reel tank with an empty reel on top and only developer to cover the bottom when at rest. Invert twice in 5 sec.

In either case twist 90 deg when you set it down so as not to set up a particular pattern. Agitation must be vigorous and random.

This is a guaranteed solution.

Water and stop can work equally well although the acid can stop the development immediately. There is a grain penalty for either. I recommend you skip it altogether and go straight into the fix.

 

[Loose Gravel]

Oh another one who thinks surge marks exist. They don`t. They are simply areas that received the proper agitation compared to the areas that that did not so they are under developed.

This is what I thought surge marks were. Anyway, that's what I see with steel and it goes away with plastic. I think your right about the random agitation working.

This info wasn't on Kodak's website when I needed it --- 25 years ago.

 

[Mike-D]

I believe that pinholes resulted from acid stop bath coming into contact with developer containing sodium carbonate. Kodalk was developed in the 1930s to combat this problem. Carbonate in developers is very rare now days.

That being said I have always used water stop bath. Fill the tank with water (same temp as developer and fix) agitate for 15 seconds (12 inversions for me) drain and repeat. Then into the fix. Always used stainless steel too.

Didn't even have to change my procedure when I finally did use a carbonate accelerated developer!

Mike D

 

[Ole]

Carbonate in developers is very rare now days.

Not all that rare - two of my favorite developers (Beutler's/Neofin and Pyrocat-HD) both contain carbonate.

 

[Donald Miller]

Quote:
"I believe that pinholes resulted from acid stop bath coming into contact with developer containing sodium carbonate. Kodalk was developed in the 1930s to combat this problem. Carbonate in developers is very rare now days."

To the developers containing carbonate that Ole mentioned, I would add ABC Pyro which is used fairly extensively today.

 

[Donald Qualls]

Not to mention (in terms of carbonate alkalized developers) Caffenol, Diafine, and Dektol (the last not usually used for film these days, but it still works).

 

[srs5694]

A few more carbonate developers: Suzuki's DS-12, Gainer's PC-Glycol (with sodium carbonate solution as stock B), and Agfa/Ansco 12.

 

[donbga]

Is it possible that a water stop bath is less effective in stopping development at the edges of the film where it is in contact with the reels?

In a word yes!

Always use an acid stop for paper and film. It will eliminate many problems down the line after the developer and provide consistent repeatable results.

I've been processing film for over 30 years and have never seen pinholes. Just dilute the stop properly.

Don Bryant

 

[Photo Engineer]

In the early days of photography, emulsions were unhardened or poorly hardened. This led to the formation of bubbles by reaction of carbonate from developer carryover to the acid in the stop bath or acid fixer. The reaction with an acid fixer can take place even with a short rinse of water.

However, first it must be said that the carbon dioxide that is formed is in very tiny amount and it dissolves rapidly in the water of the stop bath, and so when these bubbles were observed, it was usually in a deep tank process where hydrostatic pressure prevented the bubbles from being released until the film or paper approached the surface of the tank and the pressure was reduced.

The result was that the bubbles didn't show up in tray or shallow tank processes, but did sometimes in deep tank photofinishing processes. This was seldom and only seen pre-1960s.

In the 60s, most major film manufacturers switched over to hardeners that allow processing up to 100F for color films and papers and over 68F for B&W films and papers. These new products are not affected by the use of an acid stop bath in any way as far as can be determined, even in deep tanks or at high temperatures (RA color paper with a stop at 100F has no problems with pinholes and the RA and C41 developers are both carbonate based).

The only way I can generate bubbles (not pinholes) is to coat a totally unhardened emulsion at very high gelatin and then use an acid stop. I can see bubbles form before my eyes, and they don't form in the stop, they form in the acid hardener fix and can even form in the wash. They appear more like blisters.

I must add that not all manufacturers use these new modern hardeners, and therefore you might, in extreme cases, see blisters or marks from acid/carbonate interaction in such films.

I have never observed even this, but I warn you of the possibility.

I have used acid stops for film and paper for over 30 years with absolutely no problem, but have had problems of one sort or another with using a water rinse after development.

I will continue to use an acid stop.

PE

 

[Ole]

I have had bubbles/blisters on EFKE rollfilm in a Paterson tank with an acid stop. I like EFKE films, and especially in "Beutler's". Reason enough for me to avoid acid stop if I can.

 

[Donald Qualls]

Same is true with J&C Pro 100 -- acid stop or temperature above 68 F can lead to blisters or pinholes. Both this film and Efke are completely unhardened emulsions similar to those in general use prior to 1960.

 

[Photo Engineer]

The films you cite are hardened, but probably do not use the more modern technology available to the major manufacturers.

If they were unhardened, they would be unsalable and unusable in today's market. You would be surprised at how soft unhardened gelatin is, and how easy it frills or reticulates.

PE

 

[SchwinnParamount]

In the early days of photography, emulsions were unhardened or poorly hardened. This led to the formation of bubbles by reaction of carbonate from developer carryover to the acid in the stop bath or acid fixer. The reaction with an acid fixer can take place even with a short rinse of water.

....

I have used acid stops for film and paper for over 30 years with absolutely no problem, but have had problems of one sort or another with using a water rinse after development.

I will continue to use an acid stop.

PE

Thank you for that information! I've been educated. A prior poster described the proper way to fill a development tank (developer just above the level of the reels or single filled reel in a multi reel tank). I had no idea. I had been under the impression that the more developer you pour into the can, the better.

 

[djkloss]

Thank you for that information! I've been educated. A prior poster described the proper way to fill a development tank (developer just above the level of the reels or single filled reel in a multi reel tank). I had no idea. I had been under the impression that the more developer you pour into the can, the better.

So what exactly would the results look like if you used too much solution in the tank? I, too thought more was better. I know sometimes not enough leaves for uneveness and you can see a stripe along the edge from not receiving enough developer. I also read somewhere in Adams 'the negative' about letting the film 'sit' in the water and not agitating it, but that was with Two Bath Developing. Is that the same or different?

Thank you.....

-Dorothy

 

[Ole]

"Too much developer" is when it doesn't "glug" when inverted. That means the agitation is less efficient. You get uneven and/or weak development.

Adams' water bath treatment is something completely different.

 

[Gerald Koch]

I had been under the impression that the more developer you pour into the can, the better.

If you completely fill the tank with developer then it is nearly impossible to obtain any agitation. Proper agitation depends on having some space for the developer to move about.

Developers like DS-12 which contain only a very small amount of carbonate are unlikely to cause pinholes. In order for bubbles to form the local area in the emulsion must be saturated with carbon dioxide.