Methods and systems for inspecting a specimen are provided. One system includes an inspection subsystem configured for directing light to an area on the specimen and for generating output responsive to light from the area on the specimen. The system also includes a first gas flow subsystem configured for replacing a gas in a first local volume surrounding the area on the specimen with a first medium that scatters less of the light than the gas. In addition, the system includes a second gas flow subsystem configured for replacing the gas in a second local volume proximate the first local volume with a second medium different than the first medium. The system further includes a computer subsystem configured for detecting abnormalities on the specimen based on the output.