Fogging Photographs Showing Electric Field

Abstract

We introduce fogging photography, a new method for recording electric field distribution. When a photographic film is exposed to short light flash synchronized with strong applied electric field, the optical density of developed film is significantly decreased depending on the field strength. Based on this phenomenon the image of non-uniform electric field can be easily obtained. For the purpose of basic understanding of the underlying mechanism as well as for f urther application of the method, density decrease vs. applied voltage relationship and the effect of time-lag between the synchronized fogging flash and the voltage pulse were studied under uniform fields. The decay rate of Dember photovoltage was also measured for comparison. We concluded that unfavorable separation of photoelectrons and interstitial silver ions might be a principal cause of the desensitization by the electric field.