Epson GT-6500 EN - Manual (Page 32)

Zoom
The zoom function causes an image scanned at the same resolution as
the output device to be output at a greater size than the original. The
zoom function can be set independently from the resolution setting.
Since the zoom function enlarges or shrinks the image of the original
document, the data amount expands or shrinks in response to the
zoom setting.
1-18 Overview