Mystery white flame marks on film

[vau-ka]

I just developed some film which has some strange light marks: There is a flame-shaped pattern regurarly right between frames, and then there is one frame which is totally whitened out. The negatives after the whitened-out frame show the same pattern.

I have shown this to some guys and no one knows what it is. Anyone has an idea?

I think I changed the lens at this time when the whitened out frame occurred, so maybe there is a problem with the shutter... but why would be the light mark always exactly between frames?

I attach two scans of the film: One is more or less original, the other with max contrast. Sorry for the poor quality, I hope its still good enough to see the problem.

any help/clue would be greatly appreciated.

Thank you!

vinzenz

P.S. The film is from a Canon 7.

 

[sevo]

This is not evident from the scan (where opaque areas register as grey/black), but if your description of "white marks on the film" is literal, that is incomplete fixing. The streaks matching the perforation (with the film better fixed where the perforations allowed for better circulation) does further support that. Keep the film dark until you pre-soak and re-fix it (with fresh fixer, presumably the old one is depleted).

 

[vau-ka]

Thanks for your advice, I will try out and see if it fixes the problem. I am sorry for the poor quality of the scan, but the white-grey streaks are opaque as you said. The thing is, they do not really correspond to the holes in the film (i have this on some other films and this looks different). Rather, the white streaks appear always right between frames, and in frame 12, which is totally whitened out. Maybe there is a problem with the camera shutter, which allows some light leaking in when the film is transported?

 

[Sparrow]

... it's difficult to see, but I wondered if the shutter was leaking light while the film is being wound on?

 

[x-ray]

It appears to be poor fixing.