The best resolution setting for your image depends on the type of image you are scanning and your final output device, as well as the capabilities of your scanner. The following table shows the best scanning resolutions for most needs.

Optimum scanning resolutions

Output device

Line art

Grayscale

Color

 

 

 

 

Monochrome printer

300-600

80-170

 

 

 

 

Desktop or office

300-720

150-240

150-240

color printer

 

 

 

 

 

 

 

Printing press or

600-1200

150-350

150-350

imagesetter

 

 

 

 

 

 

 

Computer Screen

72

72

72

 

 

 

 

The Resolution setting depends on the Pixel Depth setting in the Image Type dialog box. When Pixel Depth is set to 8 Color or Black & White, you can set the Drawing/Halftone resolution. For other Pixel Depth settings, you can set the Photo resolution.

Note:

The Resolution setting is closely related to the Image Size and Scale settings (described in this chapter). If you change them arbitrarily, the resulting image may not be what you expected.

The higher the resolution you select, the larger the resulting image file. For example, an 8.5 × 11 photograph scanned at

300 dpi can produce a 24MB file. The same photograph scanned at 72 dpi creates only a 1.36MB file. Large files take longer to process and print, so consider the limitations of your computer system and hard disk drive when you select a resolution. To keep file sizes manageable, select the lowest possible resolution that gives acceptable quality.

3-14Capturing Images From Within Applications