Epson PERFECTION V600 PHOTO - Manual (Page 55)

In the Full Auto Mode window, click Customize. The Customize window appears.
Click the Specify resolution for Full Auto Mode check box and select the number of dpi (dots per inch) at which
you want to scan.
Selecting the Resolution in Home Mode
To change the resolution, first select Other as the Destination setting.
Click the arrow next to the Resolution list and select the number of dpi (dots per inch) at which you want to scan.
Selecting the Resolution in Office Mode or Professional Mode
You can select the resolution you want at any time.
Office Mode