Brother MFC J6910DW - Manual (Page 147)

Scanning
140
9
d
Load your document again.
Note
Skip this step if you loaded the document on the scanner glass in step a.
e
Adjust the settings for Resolution, Scan Type, Brightness and Contrast in the Scanner Setup dialog
box as needed.
f Click Start.
This time only the chosen area of the document appears in the application window.
g You can refine the image in your editing software.
Note
Pre-Scanning is not available when choosing Duplex (two-sided) Scanning. (For MFC-J6910DW)