Epson Expression 800 User Manual - TWAIN 32 - Page 20

Choosing the Scan Resolution Resolution refers to how many dots per inch (dpi) or dots per centimeter (dpcm) you want your scanned image to contain. These sections tell you how to select the best resolution for your image:  Factors to Consider in Selecting Resolution  Changing the Resolution Factors to Consider in Selecting Resolution The best resolution for a scanned image depends on the type of image you're scanning and your final output device. The higher a resolution you select, the larger the resulting image file. For example, an 8.5 × 11-inch original scanned at 300 dpi can produce a 24MB file. The same original scanned at 72 dpi creates only a 1.3MB file. If your scanned image is intended only for on-screen viewing, you can scan at 72 dpi to reduce your file size. Large files take longer to process and print, so consider the practical limitations of your computer system and hard disk drive when selecting a resolution. To keep your file size manageable, select the lowest possible resolution that gives acceptable quality. As a rule of thumb for any image except line art, use a scanning resolution that is approximately one third of your output resolution. For example, use a scanning resolution up to 100 dpi with a 300 dpi laser printer, and up to 200 dpi with a 600 dpi laser printer. Basic Scanning Page 20