Microtek 3700 User Guide

Basic Scanning Concepts

This section covers basic scanning concepts. If you already have basic 

scanning knowledge, you may skip this section.

 

 

 

 

 

A rule of thumb for choosing the right Quality Factor is, for images with 

printing screens less than or equal to 133 lines per inch, set Quality Factor 

to 2; above 133 lines per inch, set it to 1.5; for continuous tone printers, 

set it to 1.0.

If you are outputting images to a monitor (such as doing multimedia 

work), you need not scan images higher than 72 ppi, as monitors are 

capable of only showing images up to 72 ppi. A higher-resolution image 

will not be any clearer on the monitor and will simply create larger files.

Remember that the higher the resolution, the larger your image file will 

be. For instance, an 8.5" x 11" color photograph scanned at 75 ppi takes 

up about 1.6 megabytes (MB). Doubling resolution to 150 ppi will increase 

the file size four times - to approximately 6.3MB! Going to 300 ppi will 

increase file size to 26.2MB.

What you need to do is to select the lowest possible resolution that still 

gives you good image quality in order to keep file sizes manageable.

A scanner is a device that captures an image and converts it into a digital 

file:///D|/sw56/Basic.htm (1 of 5) [8/15/03 4:18:11 PM]