Drum scanner
From The Glossary of Digital Photography
A scanner used to create a digital file by scanning a film or print image on a drum scanner. Drum scanners usually produce the highest-quality file because the photo multiplier tubes they use are more sensitive to light than the CCDs used by most desktop or flatbed scanners. They can scan at resolutions higher than film can record. Drum scanners are much more expensive than desktop flatbed scanners, so their use is declining, especially as prices drop on desktop scanners. Drum scanners require that the image to be scanned be soaked in a special oil, to ensure that good contact is made with the glass-cylinder scanning drum. This wet mounting is much less convenient to use than a flatbed scanner. See also scanner
