Surge marks on CN film?

[originalwinslow]

Greetings all,

I have been consistently running into an issue for the couple months. I have some negatives that come out with strong staining along the edge of the negatives and projecting out from the sprocket holes. In almost all cases it is on Portra film. I develop in a 5-roll paterson tank with manual agitation - four gentle inversions every 30 seconds after 30 seconds of initial (also gentle) agitation. I have seen others post about the possibility of inversions causing surge marks in larger tanks due to the force of the chemicals running across the film. However, the issue persisted even when changing to rotary agitation with the "swizzle stick."

I have been unable to recreate the problem when running test strips. I ran a test with much more vigorous agitation than usual in the same fully-filled 5-roll tank and saw absolutely no marks. I thought that this could eliminate agitation as the culprit.

I tried re-fixing affected negatives in fresh fixer. No change. Re-bleaching and fixing. No change. I'll run devs and see no notable staining, and then the next day the staining returns. Yesterday I ran 5 rolls, three Portra and two Ultramax. Only the Portra showed staining, the Ultramax showed absolutely no sign.

The stain is also strongest ALWAYS on the same side of the negatives regardless of their location in the tank (more towards the bottom or top). It is also present in some 120 negatives (PORTRA ALWAYS). The one thing I did change in my process is moving to Kodak CN fixer, after which the problem started cropping up at least much more noticeably. But if refixing does not eliminate it then the fixer shouldn't be the issue...I should mention that I never see this in my ECN-2 devs (using the same bleach and fix) so I'm wary on blaming the secondaries.

I have run out of tests to run as far as I can think of. Anybody have any ideas? Could the film already be somehow stained before processing?

I have included images of a negative as well as a conversion.

 

[John Salim]

That's simply a lack of proper agitation.

John S

 

[originalwinslow]

That's simply a lack of proper agitation.

John S

I doubt it. I was doing quite forceful inversions when they began cropping up.

 

[blee1996]

Do you run acidic stop bath between color developer and bleach?

 

[originalwinslow]

Do you run acidic stop bath between color developer and bleach?

Yes, 2% acetic acid stop bath for 1 min with constant agitation

 

[koraks]

I can only confirm that I've seen/had a very similar problem, but (1) refixing did solve it, (2) there was a perfectly reasonable cause for it (using too dilute fixer one shot; I was seeing how little I could get away with) and (3) it didn't involve sprocket hole anomalies, but rather followed different patterns.

Sprocket-hole related anomalies are a bit more likely to point towards light leak problems during film handling, esp. if they're along one edge.

The stain is also strongest ALWAYS on the same side of the negatives regardless of their location in the tank (more towards the bottom or top).

That's an important clue and it points more towards a light leak issue than one with chemistry.
In what part of your total film handling process do the films have the same orientation?
Can you confirm it's always the bottom edge of the film that's affected?
How do you handle the exposed film; i.e. what's your process of getting it from its packaging into the processing tank? What kind of tank do you use? (5-reel Paterson; you mentioned it)
You mention it also occurs on 120 film; what does it look like in that case?
Can you show examples scanned edge to edge and not just the image frame? Does the problem show on non-image areas (film edges, leader/trailer sections)?

 

[loccdor]

You mention it also occurs on 120 film; what does it look like in that case?

Yes, I'm not imagining what a sprocket hole pattern looks like when applied to 120 film. I think those could be 2 separate problems.

And maybe the part where you only see it on Portra doesn't mean it doesn't happen with everything, just something about Portra's base or the way you expose it making it more visible.