Vacuum back

Is a camera back with a perforated plate through which air is drawn by a pump. A sheet of film is therefore sucked flat against the plate and held firmly during exposure used for special large format cameras such as copying devices where dimensional accuracy is critical.
Found on http://www.rodsmith.org.uk/photographic%20glossary/rods%20photographic%20gl

Vacuum back

Is a camera back with a perforated plate through which air is drawn by a pump. A sheet of film is therefore sucked flat against the plate and held firmly during exposure used for special large format cameras such as copying devices where dimensional accuracy is critical
Found on http://www.encyclo.co.uk/local/21048

Vacuum Back

Is a camera back with a perforated plate through which air is drawn by a pump. A sheet of film is th
Found on http://www.superglossary.com/Glossary/Entertainment/Photography/
No exact match found