On the Scan Parameters Dialog you can find an Advanced... button. If you use it, it invokes original program you have installed for your scanner. Now you can set all options which you normally set outside our program, to get the correctly scanned image. It must be done because we can set only those options which are common for all scanners.

Specific scanners have more options so we need to pre-scan some image to "get know" how they should be set. If, in future, you decide that some of additional options should be changed, you must repeat configuration, as described above, using new values for these option.