Stripes on the edge of my negative - Chamonix 8x10

[thomashobbs]

Hi,

I just bought a Chamonix 8x10 and processed my first sheets from it and I'm getting stripes on the long edge of my negative, parallel to and mimicking the form of the groove that holds the film in the holder. I suspect this is some kind of reflection going on because the film holder is too shiny or its not sitting tightly enough in the back of the camera.

See the attached picture for an example of what I'm talking about. I'm attaching the whole picture and a detail of the corner that shows these stripes. I was using a plastic Fidelity film holder.

I'm certain this is not a processing issue because in the same batch I processed film from another camera (a Wehman 8x10) and the negatives do not exhibit this problem.

Can anyone advise on how to modify either the camera or the film holders so as to eliminate this problem?

Thanks!

[Regular Rod]

I think the parallel shading to the film edge is to do with the scanning. The other diagonal stripes look like something on the film perhaps. If they were scratches they would be black.

RR

[Ken Lee]

Aren't those scratches introduced when handling ? What film ? Some brands are more prone to this than others ?

[Light Guru]

It looks more like the sheet of film moved a little bit during the exposure. When putting the holder in the camera to take the photo just tap the holder a few times to get the film to settle.

[Christopher Barrett]

I see two things, some diagonal handling scratches, but then, yes, some weird ghosting of the rebate. Do you have wooden holders? I have Chamonix 4x10 wooden holders and there is a satin finish on the wood. I could see how light reflecting off that edge would cause the ghosting. We should ask Hugo about that.

CB

[Colin Graham]

I've gotten these as well. They are visible on the film, so it's not a scanning artifact. And the bands are getting less density, not more. So it's not a light leak. Are you using a slosher tray? Sometimes sheets of film will curl in the developer, and the edges will lift slightly out of the solution and the surface tension will keep the developer from the edges of the film, resulting in these perfectly parallel lines of decreasing density. Anyway, that was always my best guess when I used to get these. Doesn't always happen to every sheet of film in the same batch. It quit happening when I started using more solution.

[thomashobbs]

The diagonal "scratches" in the upper left corner are actually light trails of planes taking off, so no worries about that.

The "weird ghosting of the rebate" is the problem I'm talking about. I process the film in a jobo but it's not the processing because in the very same batch I processed a couple of sheets I shot with another camera but the same Fidelity plastic film holders and they do not exibit the ghosting. It's not from having the film move during the exposure because the rest of the image is sharp.

So, I'm pretty sure it's some kind of light leak/reflection and I'm curious if anyone has encountered this problem before and if they know if any solutions.

Thanks!

[thomashobbs]

OK, OK, I just figured it out.

That weird ghosting came from scanning the negative on my flatbed (with no holder). The edges must have curled, casting a shadow or reflecting back on the glass. I just did a wet-mount scan of the same negative and... No ghosting!

I feel a little stupid now but thanks for your responses!

[Regular Rod]

OK, OK, I just figured it out.

That weird ghosting came from scanning the negative on my flatbed (with no holder). The edges must have curled, casting a shadow or reflecting back on the glass. I just did a wet-mount scan of the same negative and... No ghosting!

I feel a little stupid now but thanks for your responses!

You can also get round the problem with a sheet of ANR glass laid on the film and scan with emulsion side down, then horizontal flip after scanning.

RR

[Colin Graham]

Glad you figured out what was causing you problem. In my case the artifact is definitely visible in the negative, although I'm starting to think it's a similar issue, except it's happening in camera. I realized that the film holder opening in my camera back is pretty close to actual film size, so with any excessive front movements I think the back's edge was casting a shadow within the image projection of the lens, giving this penumbra effect on the film edge relative to the excessive shift or rise. I beveled the back opening to see if that fixes it.

I was convinced it was a development issue because I haven't seen it in a long time and thought I'd solved it, but the problem is likely just dormant because I rarely use a lot of front movements.

[timparkin]

I've seen this before and it was caused by light bouncing off the inside of the bellows and being shaded by the camera interior and/or the thickness of the rebate on the dark slide... using a lens hood is fairly important especially with large coverage lenses.