A scanner is a device that uses light-sensing equipment to import documents into programs to be edited and saved.
They can be used to convert photographs into computer images or printed text into an editable text document.
While not a very common component, scanners are used heavily by professionals such as publishers and photographers.
You should consider getting a scanner only if you would use it regularly.
For most people, the occasional convenience that scanners provide is not worth their cost.
There are alternatives to the functions scanners provide that are much cheaper, if less convenient.
If you need a text document converted to a computer document file, you can usually have your local print shop scan it for you for a small fee.
And most photo-development shops will put a roll of film on a Photo CD for a nominal cost.
However, the purchase of a scanner is becoming increasingly justifiable as scanners fall in price.
Scanners range widely in sophistication, hardware interface, and design. The two
most important attributes to consider in terms of sophistication are resolution (in dots per inch, dpi)
and color depth (in bits). The resolution gives an idea of how fine an image the
scanner can produce; if the scanner can differentiate more dots in a single square inch, images produced will look less
blocky or pixilated and more life-like. The color depth gives an idea of how precisely
the colors in images produced will mirror the ones they represent in original documents.
If the number is greater (36-bit compared to 30-bit), the scanner theoretically
has a larger palette of colors to work with. However, you likely would not notice any
great difference between 24-bit color and 30-bit color; the difference is very subtle,
and you will not see it at all if your display is set to a lower color depth or you
save an image with a lower-quality file type. Usually, color depth is not a feature
upon which you should base your buying decision or for which you should pay more money.
The three main scanner designs are flatbed, sheet-fed, and handheld.
A flatbed scanner has a fixed glass surface upon which documents are placed to be scanned.
Flatbeds are the bulkiest and most space-consuming type, but they allow bound documents
to be scanned, and pose no risk to documents getting damaged. Sheet-fed scanners,
on the other hand, which use wheels or rollers to move a document through them,
are very compact, but are too small for most bound documents and can sometimes scratch
photos or tear paper. Hand held scanners, which require the user to move the scanner over
the document in a relatively smooth and even motion, are compact and will work with any
type of document without any damage, but are apt to produce skewed or incomplete images.
All scanners use one of three hardware interfaces to connect to the computer: SCSI, parallel port, or USB.
Parallel port scanners are usually the easiest to install, because they attach directly to the computer's printer port and require no special hardware setup.
SCSI scanners, the installation of which is discussed here, have the advantage that they can transfer images more quickly to the computer.
However, they require that a SCSI controller, a relatively uncommon component, be installed inside the computer.
A SCSI controller must be either included with the scanner or purchased separately, so SCSI scanners are usually more expensive than parallel port scanners.
USB scanners are just as easy to install on a Windows 98 computer as parallel port scanners.
However, because USB technology was very new at the time of this writing, it was too early to determine how USB scanners compare to SCSI and parallel port scanners in terms of cost and performance.
Scanners range in price from $100 to over $500. When buying a scanner, you can easily narrow your choices to a few models by deciding on a design, hardware interface, and degree of sophistication that fits your budget.
Another factor to take into consideration is the software included with the scanner.
Every scanner should have a driver that lets you control the operation of the scanner when you're importing a document, an image editing program, and an OCR program to convert acquired text to editable text.
Before buying a scanner, make sure that you will have surface space available close enough to the computer that you can attach a cable.
If you're going to buy a SCSI scanner and you do not already have a SCSI controller, make sure there is a free expansion slot available for the type of controller (either ISA or PCI) that you plan to use.
It takes about 1 hour to install a SCSI scanner. No tools are needed.
Click here for a list of links to SCSI scanner manufacturers.