Transparency attachment
A reflective document or transparency unit (engl. T rans p arency a dapter or t rans p arency u nit) means in the cover or an additional device in a flatbed scanner for digitizing slide or negative films . Such a unit is integrated in many commercially available flatbed scanners. With the help of an adapter template, framed slides or slide or negative film strips can be precisely scanned, depending on the design, other types of transparent templates.
Depending on the source material and scanner or point density ( image resolution ), sufficiently good results can be achieved with the transparency unit of commercially available devices for private use. For higher quality or professional purposes (e.g. digitizing entire collections), special scanners, such as slide scanners , are usually used.
functionality
Framed slides or film strips are precisely placed in the cut-outs of a template on the scanning surface and are illuminated from above through a matt screen during the scanning process. The lighting from below used for paper templates is switched off. This captures the translucent image instead of a reflected paper image. The stencil is made of black plastic to avoid artifacts from overexposure. As a rule, the scanner software is adapted to the unit, recognizes the images and automatically takes over the cutting.