An umbrella term for a variety of techniques of overexposure, either of the negative while still in the camera or of the print during development in the darkroon. The excess light cuases a partial reversal of tones: light areas become dark and light areas that appear in prints flashed with a bright light while still light sensitive. Though solarization has been known to photographers since the invention of the medium, the chemical mechanism by which it occurs is still not fully understood by scientists and is difficult is control.
