Dark bands in film rebate after development - I have a theory...

[logan2z]

As I mentioned in another thread, I just developed my first roll of film at home a few days ago - Tri-X 400 in HC-110. I had an initial snafu caused by a misread of the Ilford data sheet that called for a 1:4 dilution of Rapid Fixer for film rather than 1:9 that I use for paper. After realizing that mistake, I re-fixed using a 1:4 solution and re-washed. The dried film showed quite a few streaks and water spots so I did one more wash with the final rinse using distilled water (and, of course, photoflo) and most of the spots/streaks are gone.

At this point the film looked pretty good, but I noticed some intermittent dark bands/staining running vertically along both sides of the rebate. None of these marks affected the image area. I've never seen these before on any of the rolls I've had developed at a lab so I figured I'd screwed something up. But then something occurred to me - maybe these were caused by the rebate's contact with the reel and the area in contact with the reel not having an opportunity to fully fix. Of course these won't show up in my lab-developed film since the lab uses a dip-and-dunk machine. So I think I've solved that mystery, but is that a common issue with home-developed film using reels? Is everyone whose developing at home seeing these marks in the rebate? Can I assume this imperfectly fixed rebate area will have no long term affects on the film?

It's strange that in all of the reading I did about home developing before starting this I never once heard anyone mention this.

I've included a photo of the negatives to better illustrate what I'm referring to. The 'bands' in the rebate are circled in red. Ignore the wide dark bands behind the film strip, that's my iPhone freaking out when attempting to take a photo of the film strip on an LED lightpad.

 

[logan2z]

I just found an old Photrio thread that looks like it answers my question:

https://www.photrio.com/forum/threads/defects-after-developing-ilford-delta-400.160914/

 

[Ivo Stunga]

No worries - chems didn't get to these spots due to contact with the reel, and it affects nothing, since it's not a image area. And it won't grow in time or anything.

Sometimes they appear, often don't. Increased agitation frequency can help to deal with it (and it'll increase contrast too), but why should one bother?

 

[logan2z]

No worries - chems didn't get to these spots due to contact with the reel, and it affects nothing, since it's not a image area. And it won't grow in time or anything.

Sometimes they appear, often don't. Increased agitation frequency can help to deal with it (and it'll increase contrast too), but why should one bother?

Thanks for confirming!

 

[AgX]

Look carefully at your spiral. The flanks for instance at the Jobo clear spirals are inclined at both sides.

 

[logan2z]

Look carefully at your spiral. The flanks for instance at the Jobo clear spirals are inclined at both sides.

I'm using a Hewes reel. I don't see anything obvious in the design of the reel that would help prevent these bands in the rebate if they're caused by the film contacting the reel.

 

[AgX]

What I meant was that if the film is warped around its longitudinal axis, there would be no area contact whatsover, if the film is flat and the spiral flanks are not incilined, there could be area contact, if the the film is flat and the spiral flanks are inclined, there could be no area contact.

So much for the theory.

 

[logan2z]

What I meant was that if the film is warped around its longitudinal axis, there would be no area contact whatsover, if the film is flat and the spiral flanks are not incilined, there could be area contact, if the the film is flat and the spiral flanks are inclined, there could be no area contact.

So much for the theory.

Understood. It seems like this may be unavoidable with these reels.

I took a close look at the negatives under a loupe and, despite the fact that I shot the roll at EI200, they look a bit thin to me with not enough shadow detail. I guess the next thing I should do is some testing to figure out my personal film speed and development time. A project for the weekend ..

 

[Andrew O'Neill]

I see them on some of my students' negatives. We use K1000's. I always thought that they were from stress on the film as it's advanced in the camera.

 

[logan2z]

I see them on some of my students' negatives. We use K1000's. I always thought that they were from stress on the film as it's advanced in the camera.

That was one of my early theories too but apparently not. Film shot with the same camera and developed at a lab using dip-and-dunk machines does not show these marks.

 

[reddesert]

I get marks like this sometimes. I use steel reels. It's from the fixer and wash aid not contacting that area because it was pressed very tightly against the reel at that point. Presumably it varies in location because the film is wound a little tighter in some places than others. The cause is pretty obvious on some of my film because the mark has the color of unprocessed film, not a fully black mark like exposed and developed film. If you take the loose film and drop it in some fixer without putting it on a reel, it will likely clear these marks. It doesn't affect anything since it's in the rebate, so I don't bother. I guess it would be an issue if you were exposing the whole film like in a Sprocket Rocket.

 

[Huss]

I often get these marks when I dev my B&W film, but have never been concerned about it because it never was in the image itself.
For once my OCD did not kick in!

 

[logan2z]

For once my OCD did not kick in!

You seem to have better control over yours than I do of mine

 

[Ivo Stunga]

I see them on some of my students' negatives. We use K1000's. I always thought that they were from stress on the film as it's advanced in the camera.

Then the sprocket gears would've ripped the film apart before any stretching of film can occur. Soviet Zenit cameras with metal gears love to do this : D

 

[grain elevator]

For once m y OCD did not kick in!

No? Then how about this: Have you considered that these areas, if they don't receive proper washing, may retain fixer that could diffuse out and destroy the whole negative over time? You're welcome!

 

[Don_ih]

No? Then how about this: Have you considered that these areas, if they don't receive proper washing, may retain fixer that could diffuse out and destroy the whole negative over time? You're welcome!

I think it's slightly more likely lemmings will invade with trombones and steal all the marbles from the cereal box.

 

[grain elevator]

I think it's slightly more likely lemmings will invade with trombones and steal all the marbles from the cereal box.

Adding a new worry doesn't make my other worries go away!

 

[AgX]

Look carefully at your spiral. The flanks for instance at the Jobo clear spirals are inclined at both sides.

What I meant was that if the film is warped around its longitudinal axis, there would be no area contact whatsover, if the film is flat and the spiral flanks are not incilined, there could be area contact, if the the film is flat and the spiral flanks are inclined, there could be no area contact.

So much for the theory.

Has someone compared the various plastic spirals on this feature?

 

[MattKing]

No? Then how about this: Have you considered that these areas, if they don't receive proper washing, may retain fixer that could diffuse out and destroy the whole negative over time? You're welcome!

I think that it is more likely that those areas haven't been developed or fixed, so they are essentially areas of printed out emulsion.