scanning medium format negs as A12 for contact sheet

[ambermai23]

Hi,
I would like to be able to scan the whole plastic sheet of my medium format negatives just as a contact sheet but I can't seem to do that with Silverfast SE. Only the center strip is visible and I don't know how to chance the scanning window so that it scans A4 instead. Can you help?
Thank you,
Amber
PS I've attached a screen grab.

[LSI_Luebker]

Dear Customer,

when switching to Transparency mode we only do show the possible scan area which is much smaller than A4 for the most scanners.
Anyway you can Scan this whole area and than Scale scanned image to fit on an A4 page.