Definition of "Solarize" :

verb: expose to the rays of the sun or affect by exposure to the sun

verb: overexpose to sunlight

"Be careful not to solarize the photographic film."

verb: become overexposed

"The film solarized."

verb: reverse some of the tones of (a negative or print) and introduce pronounced outlines of highlights, by exposing it briefly to light, then washing and redeveloping it