The image areas will be halftoned, and the text will be impoved. The options takes 256 values from the range 0-255. In color mode this option equally affects the red, green, and blue channel. The frontend software automatically selects a low reso lution. All parameters are speci fied in milimeters.
Valid options depend on the installed options.
This option is only activated of the TPU is selected as scan source. The focus on the 2.5mm point above the glass is necessary for scans with the transparency unit, so that the scanner can focus on the film if one of the film holders is used. The current version only supports one scanner per Epson back end. This is the default, and if nothing else is speci fied the backend software will open a given patch as SCSI device. The correct special device file has to be created prior to using it with Sane.