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The images attached are taken during the cleanup at Chernobyl. The white "streaks" at the bottom of each picture are said to be from intense radiation striking the film negatives, which makes sense (that's how they were discovered after all).

Question: My main question is about the structure of those white streaks? Why are they perfectly vertical?

Guess: My guess is that they are due to the geometry of the camera's shutter, but I just don't know enough about cameras to assert this with confidence.

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    $\begingroup$ Note that the image of the bottom of the frame is formed on the top of the negative as loaded in the camera. And that gamma radiation does not respond to the lens the same way that visible light does. $\endgroup$ – dmckee May 28 at 6:26
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    $\begingroup$ Note also that the streaks may well be caused by radiation striking the film inside its canister either before or after exposure to light, rather than while it was sitting in front of the shutter curtain. $\endgroup$ – jwenting May 28 at 6:45
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    $\begingroup$ Now that I can load the images properly I'd say that the spacing and relative size of the streaks looks similar to the sprocket-hole patter of 35 mm film. $\endgroup$ – dmckee May 28 at 15:32
  • $\begingroup$ "Are said": can you link to a source for this? $\endgroup$ – rob May 28 at 20:19
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    $\begingroup$ I heard that those white streaks are defects due to incorrect manual processing of the film. $\endgroup$ – AlexD Jun 1 at 22:41
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The spacing is very similar to what would be expected from the sprocket holes on 35mm film.

enter image description here

CC image by Voxphoto.

This is consistent with the film being stored rolled-up in a cartridge, with other layers of film protecting most of the emulsion from radiation. But the removal of material for the holes reduced the absorption from that direction, leaving the extra exposure visible as streaks.

The film I'm familiar with has sprocket holes on both sides. I don't see anything similar on the top of the images, so it's possible this reflects a difference in how the film was stored. Perhaps the top of the image was stored downward and received less radiation in that direction, while the bottom of the image was stored upward. Other scenarios are possible.

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