Image Quality--Factors affecting image quality When comparing scanners, hardware resolution and color pixel depth are two features often used to gauge image quality. These two features are important, but there are a number of factors that determine image quality in a scanner, such as the following: (Many of these elements will be discussed in detail in upcoming sections of this document. ) Optical resolution and color bit depth Precision stepper motor for high quality sub-scan resolution Dynamic range control Type of lamp system used Quality of the Analog to Digital converter (ADC); Epson scanners have optimum performance for minimal noise and tight color registration. Type of focus method Color vs. monochrome CCD Optic system The Epson Expression® and GT series scanners are Epson's professional series scanners designed for excellence with respect to image quality, speed, usability, versatility, and durability. These scanners include the highest quality components. The Epson Perfection® series scanners are designed for home and entry-level corporate and graphics arts users, and are designed with the highest quality components in their price class. Image Quality--Resolution A scanner's resolution determines the amount of data that is read by the scanner. As resolution increases, so does the file size. Resolution is measured in a variety of ways. Optical resolution: This is the actual number of pixels read by the CCD (Charge Coupled Device), which measures the intensity of the light that is reflected from the image to be scanned, and converts it to an analog voltage. If a scanner has a resolution of 600 x 2400 dpi, its optical resolution is 600 dpi, which means that it can resolve 600 bits of data per inch...