Tone reversal in photographs caused by massive overexposure of the photographic emulsion to light. True solarization rarely occurs in modern emulsions, and is most commonly seen in early daguerreotypes. For the similar effect that occurs with exposure of negatives or emulsions to bright light during development, rather than at the moment of camera exposure, as was used by the Surrealists, use "Sabattier effect."

Source: Art & Architecture Thesaurus 

http://vocab.getty.edu/page/aat/300135005