Unregular stripes at the frame edges

[Centurio]

Dear Community,

I'm new to this forum. Sorry when I ask a question, that may have been treaten in the past. I'll do my best to check the forum before. However for this issue I didn't find an answer, nor here, nor in other forums.
Can you help me out, where these unregular stripes in my medium format slides could come from? I was pretty sure, the reason is insufficient distribution of developer during the C-41 process, so I tried different methods to process my slides.
First I tried a normal stand processing, what means, I just flipped the box once every 30 seconds. Then I tried rotation processing, and lastly the flip processing, with continuous flipping to make sure, the developer could be mixed up best in the box (and on the film surfaces). The slides only occur roughly vertically down the longside of the slides. So I'm pretty sure the effect has to emerge whilst developing the film in the spiral tank.
(I mostly use a Paterson Multi Reel 5 tank with 3 medium format slides and the Compard Digibase C-41 developing chemicals @38°C.)

Best thanks in advance.

Centurio

 

[Donald Qualls]

To clarify (since this is apparently a crop, as well as what seems a language conversion): are the marks parallel with length of the film or, as it seems, running crosswise on the film? Can you post a photo of the complete negative for the above image, including the unexposed rebate? That will help a lot in tracking down the problem.

 

[Centurio]

Thank you Donald, the image I posted isn't a crop. As my scanner the Coolscan 9000ED has a reflective light problem I tinkered a mask to cover just the margin of the frames. So this is the image that came out of the scanner with the mask. The border in top and bottom of the image are running longwise the film, so the stripes are running crosswise.

 

[Donald Qualls]

Stripes like that running crosswise of the film, in a conventional tank (Paterson type, stainless steel, etc., but not a Rodinax or LabBox) are generally flow marks or bromide drag. Bromide drag isn't something I'm used to hearing about in C-41 (at the least, it would only come up with developer that's been reused a number of times), so what you probably have is uneven development due to the flow of developer during agitation -- or just possibly light fogging from a cracked funnel (in a Paterson type tank) or damaged light trap (in stainless).

 

[koraks]

First I tried a normal stand processing, what means, I just flipped the box once every 30 seconds. Then I tried rotation processing, and lastly the flip processing, with continuous flipping to make sure

With which of these three agitation methods does the problem occur? In case it's all of them, it's probably not caused by agitation.

 

[Centurio]

Thank you for your fast responds guys.
Well, it occurred using each of these methods.
A developer that had been used for several times could not be the point since the image above was processed by a very freshly mixed developer.
I'm pretty sure that the Patterson tank as well as the funnel are intact and not cracked ...

 

[Centurio]

I have to mention, that this problem doesn't occur when developing black and white film.

 

[koraks]

Does the same patter occur in every frame, or is it absent or different across frames?

 

[Centurio]

No, it isn't the same pattern. It occurs unregularly just on some images. There is no regularity of any kind. On some slides it is much less visible, on some frames it doesn't occur at all. On others it is really well-marked.

 

[MattKing]

Welcome to Photrio.
For clarity, I expect you mean C41 negatives, not slides.
Can you do an experiment please. rescan your problem negatives after rotating them 180 degrees - still with the emulsion pointing down (or up), but with the image turned upside down.
If the stripes move on the image, than the problem arises in the scanning stage.

 

[Centurio]

Thank you Matt!
Yes, you're right. The term "slide" emerged due to fast writing but slowly (and faulty) translating. Of course I meant negatives.
Unfortunately it is absolutely excluded, that this is an scanning issue as I can see (very lightly but still noticeable) this effect also on the negatives themself. I'm pretty sure it emerges whilst developing but I have no further idea which step exactly is causal for this.

 

[foc]

Hi, can you show a photo of the affected strip of your negative, please? Something like this?

 

[Centurio]

When you look close, you can find these stripes pretty well also here.

 

[Donald Qualls]

...but not in the rebate. That has to be in camera. But the stripes are light on the negative, which seems like it can't happen in camera. Local underdevelopment, however (flow marks) wouldn't affect the rebate. This may be a one-off developing problem.

 

[foc]

...but not in the rebate. That has to be in camera. But the stripes are light on the negative, which seems like it can't happen in camera. Local underdevelopment, however (flow marks) wouldn't affect the rebate. This may be a one-off developing problem.

I would agree with it being in the camera, when I looked at the neg first but I'm afraid I can't see the stripes in the negative (must be old age !!) so I am wondering if it is a scan problem rather than a developing problem.

 

[Donald Qualls]

I can see faint stripes, lighter in the negative, coming down from the upper rebate in the posted picture. I'm unfamiliar with Ektar, but the clear rebate is very odd to me; with C-41 films I'm familiar with, it would be masked like deep shadows in the image.

 

[koraks]

It may still be in-camera or a process problem. On the rebate itself there's not a whole lot that's being developed, so processing isn't excluded when looking at these negs and the rebate specifically.

I'm at a loss to be honest; the only thing I can think of is fibers in the camera body itself somewhere not too far from the film plane. Some strands of wool or lint that got stuck inside the camera body perhaps. It's the best guess I have on offer, but it's a wild one.

 

[Centurio]

This may be a one-off developing problem.

What do you mean by one-off developing problem?

For the rest I totally agree.

It is very unlikely that this is an camera issue since this effect occurs also with film from other cameras (35mm as well as medium format).

 

[Centurio]

Maybe I should have mentioned this much before but:

It is very unlikely that this is an camera issue since this effect occurs also with film from other cameras (35mm as well as medium format).

With this said, it couldn't be a camera issue ... neither scanning because the effect is visible in the scan as well as on the photograph of the negative on the light table.

So it has to be a developing issue ... But what the hell specifically is it?

 

[Donald Qualls]

Okay, I thought I read that this was happening only in the one camera. I might be conflating different threads, though. If it's happening with films from different cameras and even different formats, it's got to be developing related. Does the spacing of the marks on the negative match the spacing of the spokes on the developing reel?

 

[Centurio]

Does the spacing of the marks on the negative match the spacing of the spokes on the developing reel?

That's a really nice question, I didn't really check it out, but I would say that they could match. But I'm not sure about it, maybe I should check this out ...

The question is, also if they match, what would be a solution for better results. If flipping (almost shaking) the box during the developing process couldn't mix the developer sufficiently, what else could I do to achieve a regular and clean processing of the films?!

 

[Donald Qualls]

Flow marks, if not related to developer exhaustion (like bromide drag), are often due to excessively vigorous agitation. Roll the tank over gently for each inversion, then give a quarter twist or so -- this should be a little random, rather than absolutely systematic. Each inversion should take two to two and a half seconds. Using a little more developer (say, 600 ml if the minimum to cover your film is 500 ml) often helps a bit, too.

Bromide drag, on the other hand, comes from too little agitation and partial developer exhaustion -- if you have the minimum amount of diluted developer (not your case, I know, just an example) and invert only every 3rd minute, you might get bromide drag, strips of less development "falling" down from sprocket holes or spiral ribs.

 

[Saganich]

Looks like the sky area around the stripes is comparatively under developed. A large tank with that much film surface...possible not enough chemistry issue. I would try a single roll on a fresh reel in the tank alone and see if there is any difference.

 

[Centurio]

I would try a single roll on a fresh reel in the tank alone and see if there is any difference.

I'm not absolutely sure, but as far as I remember, with a single reel in a smaller tank, that effect doesn't occurs or it occurs much lighter.
What I still don't understand, how it could be possible that, nevertheless I flip and almost shake the box with the right amount of developing chemistry, the result is that much faulty in a bigger tank. I put one roll in a 500ml tank and put 3 rolls in a 1500ml tank. So the chemistry has to be suffient. Only option is, that it is not able to mix properly and again - how could this be whilst I shake the box constantly?!

 

[Centurio]

Flow marks, if not related to developer exhaustion (like bromide drag), are often due to excessively vigorous agitation. Roll the tank over gently for each inversion, then give a quarter twist or so -- this should be a little random, rather than absolutely systematic. Each inversion should take two to two and a half seconds. Using a little more developer (say, 600 ml if the minimum to cover your film is 500 ml) often helps a bit, too.

That procedure (that I also tried in the past) unfortunately amplified that effect ... Shaking the box brought me better, but still no satisfying results.