Bubbles in the negatives

Dani · Feb 21, 2019

I'm using a Jobo CPE2+ and the stabilizer was done off the reel and in a separate container. I used a 2523 tank and used two rolls in one reel.
I did two presoaks of 30 seconds each and then pour in fresh developer, then a stop bath (it came off very foamy), then bleach, rinse, fixer, rinse and then a final rinse for 10 minutes using tap water. The stabilizer was with distilled water.

One roll was nice and clean and the other one had the issues on the last 3 frames or so.
Thank you!

WilmarcoImaging · Feb 21, 2019

Looks great.

AgX · Feb 22, 2019

WilmarcoImaging said:
Looks great.

At the background left and right you can see an image structure seemingly originating from a foam structure, seemingly not on the backdrop itself.

koraks · Feb 22, 2019

This is the result of foaming chemistry during one of the process steps, potentially development. Check the following:
* Is the volume of chemistry used correct? --> if the volume is too low, the film isn't entirely covered during processing.
* Is the cap placed correctly on the processing tank? --> incorrectly placed cap will result in loss of chemistry during processing.
* Is the rotation continuous; i.e. doesn't it stop somewhere during the process (defective processor)? --> if rotation stops for some period of time, uneven development will occur.
* Does re-blecahing and re-fixing solve the issue? --> if this helps, you know that the problem manifested itself during either bleaching or fixing and your negatives can be saved. Still you'll have to figure out what the source of the problem is.

In general, C41 chemistry in a rotation setup will foam, but this is not necessarily a problem as long as the volume of chemistry and agitation are sufficient.

The fact that the last few frames suffer from the problem, combined with the assumption that these frames were closest to the center of the tank, points into the direction of insufficient chemistry used. I think the 25xx tanks require 285ml minimum, but I round this off to 300ml. Err on the high side in case of doubt. It probably doesn't hurt to run these tanks with 350-400ml.

Dani · Feb 22, 2019

koraks said:
This is the result of foaming chemistry during one of the process steps, potentially development. Check the following:
* Is the volume of chemistry used correct? --> if the volume is too low, the film isn't entirely covered during processing.
* Is the cap placed correctly on the processing tank? --> incorrectly placed cap will result in loss of chemistry during processing.
* Is the rotation continuous; i.e. doesn't it stop somewhere during the process (defective processor)? --> if rotation stops for some period of time, uneven development will occur.
* Does re-blecahing and re-fixing solve the issue? --> if this helps, you know that the problem manifested itself during either bleaching or fixing and your negatives can be saved. Still you'll have to figure out what the source of the problem is.

In general, C41 chemistry in a rotation setup will foam, but this is not necessarily a problem as long as the volume of chemistry and agitation are sufficient.

The fact that the last few frames suffer from the problem, combined with the assumption that these frames were closest to the center of the tank, points into the direction of insufficient chemistry used. I think the 25xx tanks require 285ml minimum, but I round this off to 300ml. Err on the high side in case of doubt. It probably doesn't hurt to run these tanks with 350-400ml.

* I used 300ml and it calls for 270ml
* Yes it was placed correctly, no light leaks or anything
* I stayed with the jobo the entire time and it never stopped.
* So, just re-bleach and re-fix normally? Do those need to be at 100.4F or can be used at room temperature? I've never done that so no idea how to go about it.

Thank you for the reply!

Ces1um · Feb 22, 2019

why are the bubbles seemingly limited only to the backdrop? They seem to stop immediately once they hit the subject. Just playing devils advocate, but could your backdrop have that pattern?

Dani · Feb 22, 2019

I shot two rolls with the same setup. The previous frames didn't have any marks nor the first roll, or second roll depending on how it was loaded.

trendland · Feb 22, 2019

koraks said:
This is the result of foaming chemistry during one of the process steps, potentially development. Check the following:
* Is the volume of chemistry used correct? --> if the volume is too low, the film isn't entirely covered during processing.
* Is the cap placed correctly on the processing tank? --> incorrectly placed cap will result in loss of chemistry during processing.
* Is the rotation continuous; i.e. doesn't it stop somewhere during the process (defective processor)? --> if rotation stops for some period of time, uneven development will occur.
* Does re-blecahing and re-fixing solve the issue? --> if this helps, you know that the problem manifested itself during either bleaching or fixing and your negatives can be saved. Still you'll have to figure out what the source of the problem is.

In general, C41 chemistry in a rotation setup will foam, but this is not necessarily a problem as long as the volume of chemistry and agitation are sufficient.

The fact that the last few frames suffer from the problem, combined with the assumption that these frames were closest to the center of the tank, points into the direction of insufficient chemistry used. I think the 25xx tanks require 285ml minimum, but I round this off to 300ml. Err on the high side in case of doubt. It probably doesn't hurt to run these tanks with 350-400ml.

That all seams to be quite correct what you stated koraks. BTW : I can'tremember ever to have a bubble problem with a single development I made.
In case oft foaming chemistry (what I remember for sure) I never had an impact to the resulting negatives.
But I may imagine that with "stand developing in bw" such issues could happen.
But where are the bubbles (I am not able to identify it from OP's picture) - the photo looks Ok???
with regards

trendland · Feb 22, 2019

Dani said:
I shot two rolls with the same setup. The previous frames didn't have any marks nor the first roll, or second roll depending on how it was loaded.

Where are the bubbles Dani?

with regards

Dani · Feb 22, 2019

Near the hair of them. Here's a closeup

trendland · Feb 22, 2019

Ces1um said:
why are the bubbles seemingly limited only to the backdrop? They seem to stop immediately once they hit the subject. Just playing devils advocate, but could your backdrop have that pattern?

Ahh - the background is affected?
Yes - if this is the "bubble problem" it would be clear that it is more to be seen there. Because the more colored and saturated areas oft the picture let it not so clear seen!
There the bubbles have a Vetter "camouflage".
But seriously the background looks exact in a way I was forced to used in Studio work (not my decision) and there are different sorts in gray.
None of it is avaible without bubbles - see :

.....

So are we perhaps talking about digital artefacts from scanning workflow??

with regards

trendland · Feb 22, 2019

Dani said:
Near the hair of them. Here's a closeup

hmmm - OK ....and you also identified that from your negatives via visual inspection?

with regards

PS : The devil is often within details - Bad issue if is also onto your negatives!

Dani · Feb 22, 2019

Yes, you can see it in the negative and both sides look shiny when reflecting light so it seems it happened during developing. You have to stare a it for a little bit but it's there.

trendland · Feb 22, 2019

Dani said:
* I used 300ml and it calls for 270ml
* Yes it was placed correctly, no light leaks or anything
* I stayed with the jobo the entire time and it never stopped.
* So, just re-bleach and re-fix normally? Do those need to be at 100.4F or can be used at room temperature? I've never done that so no idea how to go about it.

Thank you for the reply!

OK at last Dani - you should avoid this next - from using a bit more c41 developer . I guess you have allways fresh c41 soup in use (insufficient developer causes a different kind oft problems in comparison you have shown Herr - I am well remembering from own experience...but I never had bubbles)

with regards

Dani · Feb 22, 2019

That’s what I’ll do next. Measure how much is the maximum I and put and try more rolls like that.
Thank you!

trendland · Feb 22, 2019

more developer in regard oft volume (350ml for example) I guess koraks matches that point best from his analysis.

with regards

MattKing · Feb 22, 2019

Are the bubbles visible on the film itself?
Otherwise, this might be a strange scanning artifact.

Dani · Feb 22, 2019

Yes they are visible on the film itself.

Photo Engineer · Feb 22, 2019

It appears to be from foam in the process. One of the active solutions (dev, bleach, fix) foamed up. If you did not use the "real" final rinse, then this might also be a problem, but if you did and the final rinse was overly foamy, this might also cause a problem if the film is not properly wiped afterwards.

PE

Dani · Feb 22, 2019

I think now that my tank was contaminated with final rinse. I just soaked it and the reel with a 50/50 water and household bleach for an hour. Hopefully that does it.

AgX · Feb 22, 2019

How could a "foamy structure" be explained during rotary processing, even with a excess of foam?
Within seconds there is a new rinse of fluid.

Foam forming then must have proceeded to an amount lowering bath level below inner spiral section.

Dani · Feb 22, 2019

I thought the same thing but I’ve heard from other jobo users that have experienced the same. One even suggested using a drop of wetting agent in the developer to avoid that in the future.

To me it’s having residue from the wetting agent that would make the next batch of developer foam in excess.

koraks · Feb 22, 2019

The only thing I could think of is a differential in diffusion of developing chemistry through the emulsion through the presence of a surfactant in the bubbles.

Photo Engineer · Feb 22, 2019

The bubbles prevent wetting of the surface with active solution for just enough time to alter diffusion of solution. Therefore, marks appear.

PE

pentaxuser · Feb 22, 2019

I wonder why the foaming effect was on the last three frames only and only on the backdrop and not any on the figures? This might be pure chance of course but it just seems strange that it is confined only to backdrop and last 3 frames. Like AgX I'd have thought that foam bubbles would over the course of rotation be spread more randomly.

On the other hand if you can see it under a loupe on the negative then it must be there on the negative. Puzzling

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