Clayden effect

Etymology
Derived from experiments described by A. W. Clayden.

Noun

 * 1)  A dark streak that appears in a photograph when there has been a very brief flash of intense light, such as a stroke of lightning, while the photographic plate is being exposed. This effect is caused by the flash causing the part of the photographic plate exposed to the intense light less sensitive, so that it is less affected than the surrounds during the rest of the exposure.