Artefacts of bromide drag?

chuckroast · Aug 15, 2023

Rumbo181 said:
@chuckroast

Maybe you would like to take a look in this post: Spots in negative, I can't find the cause.

I seems to me that your problem and mine are related even when we don't know the cause.

Ángel Luis

I am not the OP here, I was just trying to help figure out what was going on.

I did take a look at the thread you mention and that, combined with this thread, makes me suspicious of this lab box development machine.

As I recommended above, get a stainless Nikkor reel and lift rod and process the film in an open tank and see what happens. I agitate by lifting the reel with the rod and rotating it in the direction of the wind at the same time (so the film doesn't come off the reel).

You don't have to buy a fancy open tank. Any 1-2 litre plastic container will do, if you are willing to work in the dark. During development. I use three such containers:

1. Developer
2. Running water "stop bath"
3. Fixer

I develop and "stop" in the dark, put the film in fixer, and then lights on.

Here is one such configuration (I have several different ones depending on film format):

Elmarc · Aug 15, 2023

Rumbo181 said:
@chuckroast

Maybe you would like to take a look in this post: Spots in negative, I can't find the cause.

I seems to me that your problem and mine are related even when we don't know the cause.

Ángel Luis

I will reply on the other thread...

Elmarc · Aug 15, 2023

Kino said:
You've probably been "lucky" in that you haven't before had the perfect combination of large, low exposure sites adjacent to a dense, uniformly exposed area to manifest these directional effects.

This is the puzzling part for me. I have had the perfect combination of 'large low exposure sites adjacent to a dense area' with no problems in the past. Post #10 shows an example from the same roll.

Kino · Aug 15, 2023

Maybe I am wrong, but it looks like you have a lot more detail in the dense areas of that negative compared to the other, which is almost totally clear in the dense areas.

Anyway, I am speculating. You could shoot a bottom-weighted frame or two of a black square against a grey card background on your next roll and see if the same effect is produced OR you could just mark it up to bad luck and just shoot as normal.

pentaxuser · Aug 15, 2023

Elmarc, can you possible obtain a normal tank and load it by hand in a lightproof room or obtain by some means a changing bag and then see what if anything this does to cure the problem. If not then can anyone else develop a film for you in their darkroom with their chemicals and if successful with your chemicals That will isolate either the Rondinax or your chemicals. It's a process of elimination which can be tiresome and expensive unfortunately

If it does cure the problem then this clearly points to the fault being your current tank and that if you have never come across this problem before then something has changed with the Rodinax/ Lab box

pentaxuser

Elmarc · Aug 15, 2023

Kino said:
Maybe I am wrong, but it looks like you have a lot more detail in the dense areas of that negative compared to the other, which is almost totally clear in the dense areas.

Anyway, I am speculating. You could shoot a bottom-weighted frame or two of a black square against a grey card background on your next roll and see if the same effect is produced OR you could just mark it up to bad luck and just shoot as normal.

The other example may not be the best comparison, it just happened to be on the same contact sheet but I have others ;-). I will check them on the light box. Maybe these anomalies are a result of a combination of factors? Eg: density and laminar flow coinciding?
I am also speculating here..I don't know enough about the science to be certain.

Elmarc · Aug 15, 2023

pentaxuser said:
Elmarc, can you possible obtain a normal tank and load it by hand in a lightproof room or obtain by some means a changing bag and then see what if anything this does to cure the problem. If not then can anyone else develop a film for you in their darkroom with their chemicals and if successful with your chemicals That will isolate either the Rondinax or your chemicals. It's a process of elimination which can be tiresome and expensive unfortunately

If it does cure the problem then this clearly points to the fault being your current tank and that if you have never come across this problem before then something has changed with the Rodinax/ Lab box

pentaxuser

Yes, this would be the most logical process of elimination which I was hoping to avoid! But if needs must...

Elmarc · Aug 15, 2023

Are we actually clear whether bromide drag exhibits more or less density? There seemed to be some conflicting opinions earlier.

chuckroast · Aug 15, 2023

Elmarc said:
Are we actually clear whether bromide drag exhibits more or less density? There seemed to be some conflicting opinions earlier.

In my experience, bromide drag and other such development artefacts:

Show up a streaks on the negative. These can be lighter or darker but are usually darker and thus lighter in the final print.
Are caused by a lack of agitation which is needed to flush away the development byproducts
Can occur even with good agitation if the developer "traps" along a support channel that holds the negative

"My experience" in this case is over a year of testing I did with various films and support structures to make semistand and Extreme Minimal Agitation work for me. While that is not your method here, the learnings are relevant.

After following this thread, I am strongly convinced that the problems you're seeing are somehow related to the magic box you're using to develop the film. That's why I suggested eliminating it from the problem and doing simple open tank development. This will give you a tried-and-true support mechanism (a Nikor stainless steel reel), ease of agitation (with with a lift rod), and plenty of developer that a single roll of film will not exhaust.

Elmarc · Aug 15, 2023

chuckroast said:
In my experience, bromide drag and other such development artefacts:

Show up a streaks on the negative. These can be lighter or darker but are usually darker and thus lighter in the final print.

Are caused by a lack of agitation which is needed to flush away the development byproducts

Can occur even with good agitation if the developer "traps" along a support channel that holds the negative

"My experience" in this case is over a year of testing I did with various films and support structures to make semistand and Extreme Minimal Agitation work for me. While that is not your method here, the learnings are relevant.

After following this thread, I am strongly convinced that the problems you're seeing are somehow related to the magic box you're using to develop the film. That's why I suggested eliminating it from the problem and doing simple open tank development. This will give you a tried-and-true support mechanism (a Nikor stainless steel reel), ease of agitation (with with a lift rod), and plenty of developer that a single roll of film will not exhaust.

Noted. Thank you.
This problem has only recently come to light. The rondinax tank has developed countless rolls perfectly. It may be the case that the combination of these adjacent densities has set something off within the process of how the tank works ie: manual rotary. I am going to look at similar negs in my archive just out of curiosity but this type of artefact is, and would have been, easily spotted at the time.
I will first expose a roll with similar densities, increase the rotation speed and move the tank intermittently side to side as Kino suggested to possibly break up any laminar flow patterns as I am curious.
Failing that, I will try to source a Nikor (not so common in the EU) or similar reel and follow your suggestions. As a side note, the developer has always been well within the limits of minimum as confirmed by Ilford.

chuckroast · Aug 15, 2023

Elmarc said:
Noted. Thank you.
This problem has only recently come to light. The rondinax tank has developed countless rolls perfectly. It may be the case that the combination of these adjacent densities has set something off within the process of how the tank works ie: manual rotary. I am going to look at similar negs in my archive just out of curiosity but this type of artefact is, and would have been, easily spotted at the time.
I will first expose a roll with similar densities, increase the rotation speed and move the tank intermittently side to side as Kino suggested to possibly break up any laminar flow patterns as I am curious.
Failing that, I will try to source a Nikor (not so common in the EU) or similar reel and follow your suggestions. As a side note, the developer has always been well within the limits of minimum as confirmed by Ilford.

I should correct something here. In thinking about it, all the drag I can recall seeing showed up as dark steaks on the negative... And therefore as light areas on the print.

The increased developer volume isn't because of capacity concerns. It's to make sure there is enough liquid volume to wash away development artefacts during agitation. I typically use at least 1litre for even a single roll of film and 2-4 liters for sheet film. I am using highly dilute Pyrocat or D-23 so the cost to use these volumes as one shot use is negligible.

Elmarc · Aug 15, 2023

chuckroast said:
In my experience, bromide drag and other such development artefacts:

Show up a streaks on the negative. These can be lighter or darker but are usually darker and thus lighter in the final print.

Are caused by a lack of agitation which is needed to flush away the development byproducts

Can occur even with good agitation if the developer "traps" along a support channel that holds the negative

Just out of interest, when you mention 'support channel' are you referring to the grooves on the reel for example? If so, I'm presuming the possible resultant problem here would be differing edge density on the negative (if some of the developer becomes trapped) which I have never encountered.

chuckroast · Aug 15, 2023

Elmarc said:
Just out of interest, when you mention 'support channel' are you referring to the of grooves on a reel for example? If so, I'm presuming the possible resultant problem here would be differing edge density on the negative which I have never encountered.

Yes, but it's not that simple. The places where the film is supported can impair fresh developer getting there, but the resulting bromide byproducts can migrate.

When I have seen bromide drag it's either been near the film support structures OR on the part of the film nearest to the bottom of the tank... gravity appears to play a role.

For that reason, I raise film reels above the bottom of the tank with a rubber stopper or a small inverted funnel. I hang sheet film with frameless hangers and position it horizontally to keep the bottom edge well off the bottom of the tank.

Elmarc · Aug 15, 2023

chuckroast said:
Yes, but it's not that simple. The places where the film is supported can impair fresh developer getting there, but the resulting bromide byproducts can migrate.

Interesting. Can the bromide byproducts migrate as you have mentioned in such a uniform manner as in the case of my negative? I'm trying to visualise this. Could it be the case that the byproducts are building up in these adjacent areas of density and are not being washed away fast enough hence the streaking?

pentaxuser · Aug 15, 2023

chuckroast said:
The increased developer volume isn't because of capacity concerns. It's to make sure there is enough liquid volume to wash away development artefacts during agitation. I typically use at least 1litre for even a single roll of film

However as most 35mm films and thousands if not tens of thousands are successfully developed in tanks with a capacity of 250- 300 ml it just seems strange that quantities of developer amounting to about one third of a litre have avoided this problem

I can't say that increasing the developer quantity isn't the solution but the evidence points to it being low on the list of likely causes of Elmarc's problem. At least in my eyes it does

pentaxuser

chuckroast · Aug 15, 2023

pentaxuser said:
However as most 35mm films and thousands if not tens of thousands are successfully developed in tanks with a capacity of 250- 300 ml it just seems strange that quantities of developer amounting to about one third of a litre have avoided this problem

I can't say that increasing the developer quantity isn't the solution but the evidence points to it being low on the list of likely causes of Elmarc's problem. At least in my eyes it does

pentaxuser

Yes, but those are normal daylight tanks that use inversion agitation. My understanding is that the OP is using some sort of machine to agitate the film. My only point was to try tank/reel agitation in the traditional manner so as to eliminate said machine from being the guilty party.

chuckroast · Aug 15, 2023

Elmarc said:
Interesting. Can the bromide byproducts migrate as you have mentioned in such a uniform manner as in the case of my negative? I'm trying to visualise this. Could it be the case that the byproducts are building up in these adjacent areas of density and are not being washed away fast enough hence the streaking?

When it comes to drag effects, I don't think there is a good way to predict anything. IF this is bromide drag (and that's still in question), my experience is that it is always somehow agitation related. Other than that, I wouldn't make any predictions.

john_s · Aug 15, 2023

I haven't experienced "bromide drag" or artefacts due to inadequate agitation that I've noticed. (There have been other problems of course).
Since bromide is a restrainer, and theoretically should produce less development, and if bromide is released during development and if it's heavier than the developer, I would have thought that bromide drag would produce a streak of less development leading to a darker streak on the positive.
That's not to say that something released by the developer produces extra density that isn't "bromide." In fact I think I've read that one common developing agent does that but I can't remember which one.

Bill Burk · Aug 15, 2023

Elmarc said:
Only half the film is in the developer at any one time. The rotation process pushes the reel through the developing 'bath', so the developer is constantly covering the film

The streaks are happening because the dark trees don’t use very much developer compared to gray areas.

Half of the time, when the film is out of the developer, all it has to work with is a thin laminar layer of developer.

The still-relatively-fresh developer flowing from the trees gives the sky a little more development action during that half of the time.

chuckroast · Aug 15, 2023

john_s said:
I haven't experienced "bromide drag" or artefacts due to inadequate agitation that I've noticed. (There have been other problems of course).
Since bromide is a restrainer, and theoretically should produce less development, and if bromide is released during development and if it's heavier than the developer, I would have thought that bromide drag would produce a streak of less development leading to a darker streak on the positive.
That's not to say that something released by the developer produces extra density that isn't "bromide." In fact I think I've read that one common developing agent does that but I can't remember which one.

Under normal circumstances you would not. When using regular agitation - say every 30 seconds - there is frequent enough replenishment of fresh developer that there should not be any bromide side effects. This should be equally true of tank inversion agitation, lift/twirl/tilt agitation in open tanks, or nitrogen burst systems.

The issue seems to occur when some part of the film does not experience agitation regularly enough. Either there is actual drag taking place or the explanation by Bill Burke above is relevant.

Either way, the trick is to get this film into a conventional immersion tank of some sort and agitate normally.

P.S. I'm not sure the byproducts of development that drive "bromide drag" are the same things as the bromide used as a restrainer. I believe there are more complex byproducts taking place there, but I cannot seem to find a good citation for this.

chuckroast · Aug 15, 2023

Bill Burk said:
The streaks are happening because the dark trees don’t use very much developer compared to gray areas.

Half of the time, when the film is out of the developer, all it has to work with is a thin laminar layer of developer.

The still-relatively-fresh developer flowing from the trees gives the sky a little more development action during that half of the time.

If that's the mechanism, that's effectively uneven agitation, right?

John Wiegerink · Aug 15, 2023

Bill Burk said:
The streaks are happening because the dark trees don’t use very much developer compared to gray areas.

Half of the time, when the film is out of the developer, all it has to work with is a thin laminar layer of developer.

The still-relatively-fresh developer flowing from the trees gives the sky a little more development action during that half of the Tim e.

Spot on Bill! That's exactly what I was thinking when I mentioned the black trees. You laid it out much better than I ever could.

Bill Burk · Aug 16, 2023

chuckroast said:
If that's the mechanism, that's effectively uneven agitation, right?

That’s right, agitation should be turbulent and random. This is gentle and consistent. I think even when the film dips, the rotation is so smooth that the laminar layer isn’t disturbed.

Bill Burk · Aug 16, 2023

pentaxuser said:
So George, you can get bromide drag with continuous agitation and if the streaks are bromide drag then is Andrew O'Neill point nonsense His point was this "Actually, I just realised that you are showing us the positives. The drag marks are lighter. Bromide drag marks should be darker in the positive (clear in the negative).

pentaxuser

@Andrew O'Neill is right about Bromide Drag. This case is the flow of fresh developer into an adjacent area accelerating development.

Bromide slows development, as is well known based on how many comments in this thread point out.

The classic reason is no agitation (stand) and a textbook example is white billboard type on a gray background. The gray background would print with dark streaks.

Elmarc · Aug 16, 2023

Bill Burk said:
The streaks are happening because the dark trees don’t use very much developer compared to gray areas.

Half of the time, when the film is out of the developer, all it has to work with is a thin laminar layer of developer.

The still-relatively-fresh developer flowing from the trees gives the sky a little more development action during that half of the time.

This sounds quite plausible

Artefacts of bromide drag?

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