Posted 13 November 2007 - 03:03 PM
It's due to a deliberately mistimed shutter in the camera. Normally, the shutter is supposed to close over the gate before the movement advances the film to the next frame, to then be exposed when the shutter moves again to uncover the gate. But if the shutter is mistimed, the movement starts to advance to the next frame while the shutter is still moving to cover the gate, so the last percentage of the exposure on the frame is streaked. Since only the brightest objects in the frame have time to register in this brief moment, what you see are bright highlights streaking upwards vertically.
There are supposedly some post filters that simulate this effect.