Tuesday, June 22, 2010

Scanners: What To Look For

There are two main types of scanners: flatbed and document. Flatbed scanners are the most familiar to people. These include a hinged lid, much like that of a copier. You place your original on the plate, then close the lid and scan. Flatbed scanners can also include holders for scanning film or slides, making them extra flexible.

If your scanning needs involve documents rather than photos, film or slides, a document scanner is a good way to convert reams of paper documents to digital. Document scanners include an automatic document feeder (ADF), so you don't have to feed documents through the machine one at a time.

Here's what the experts say to look for when buying a scanner for your home or small business:

•Flatbed configurations are easier to use for the widest range of scanning. The Canon and Epson models in ConsumerSearch's Best Reviewed section are flatbeds; experts recommend avoiding sheet-fed and handheld units for all-purpose scanning projects. The Fujitsu corporate scanner has an automatic document feeder rather than a flatbed, as this model is intended for high-volume scanning.

•The higher the resolution the better, especially for detailed photo jobs or for enlargements. Scanner resolution is measured in dots per inch (dpi) or pixels per inch (ppi). The Canon CanoScan 8800F, for example, has an optical resolution of 4,800 by 9,600 dpi, meaning it scans 4,800 dots per inch horizontally and 9,600 dots per inch vertically. Most manufacturers reference just the first number; hence, the Canon is a 4,800 dpi scanner. Only the least expensive scanners offer less than 4,800 dpi; the Canon CanoScan LiDE 100 (*Est. $55) has a resolution of 2,400 dpi. Even these inexpensive scanners should be fine for most general-purpose document work or low-resolution photo scans destined for the Internet. Note that scanners intended solely for document work -- including high-end models -- usually have resolutions of 600 dpi, all that's needed for document scanning. Experts stress that a scanner's native optical resolution is more important than either interpolated or enhanced resolution, both of which are derived via software.

•Nearly all scanners are equipped with 48-bit color depth. Color depth refers to the number of colors that can be displayed, which is important for what the experts call "dynamic range," defined as the ability to capture subtleties within light and dark gradations. The higher the bit depth, the more colors used in the image; therefore, the larger the file size. For instance, 24-bit color corresponds to 16.7 million colors, and it's basic. If you'll be enlarging prints or scanning negatives or slides, opt for 48-bit because it can differentiate between subtle gradations. Some scanners, such as HP's Scanjet G4050 (*Est. $175), offer 96-bit color depth, and those can be a good choice if you scan original paintings or drawings, which have an even wider spectrum of colors than photographs or slides.

•Included software is standard, so look for a good package. Scanners typically come with image-editing software, plus an optical character recognition (OCR) package that converts scanned text into an editable document. Photo scanners include software to edit and manage photos on your PC. Many also include a PDF converter. Even inexpensive models now include some form of image correction software, such as Adobe Photoshop Elements, for removing flaws from damaged or dirty originals. You can expect better results, however, from higher-end models, such as Kodak's hardware-integrated Digital ICE Technology.

•If you want to convert scanned text into an editable document, you need OCR software. Editors note that getting good results with OCR can be tricky, especially when enlarging small images. If OCR is important, consider the quality of the scanner's bundled OCR software, or budget extra for a good stand-alone OCR application.


Article from http://www.consumersearch.com/scanner-reviews/important-features

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