Because flatbeds have come down drastically in price and offer superior performance, sheet-fed and handheld scanners are rapidly heading toward extinction. Unless you have special needs such as scanning odd-sized documents flatbeds are the way to go. The higher the resolution the better. The Epson Perfection 1240U is the only 1200x2400 dpi scanner in ConsumerSearch Fast Answers. A 1200x2400 dpi scanner scans 1200 dots per inch horizontally and 2400 dots per inch vertically.
Interpolation often distorts images and causes slow scanning speeds.
Don't buy a scanner with a horizontal resolution of less than 600 dpi unless you intend to use it only for text. Each bit represents a distinct level of brightness and color sensitivity. Color bit depth is much more important when scanning photos than when scanning text. Look for CCD sensors for better quality . With CCD technology, light bounces off the scanned document through a lens and onto the CCD chip, where the image is digitized.