SCANNERS


Epson Perfection 636U








April 24, 2000
Heather Rowland
CS110
9:30





    Where scanners used to only be needed by graphics professionals, now the average civilian can use them in their own home. When choosing a scanner it is important to know what your computer usage will be. The features and options you would like your scanner to have directly impacts the type of scanner and the amount of money you will have to pay for it. The prices of scanners can range from anywhere around the basic $100 scanner to the professional $20,000+ scanner.

    There are six different types of scanners: the flatbed scanner, sheetfed scanner, photo scanner, film scanner, business-card scanner, and handheld scanner. The flat bed scanner has the advantage of its speed and image quality. Some disadvantages of the flatbed are its relatively large size and that it is harder to work with odd shaped papers such as legal documents. For use around the house, user-friendly models with an external start button and a USB hookup. If the scanner will be used in an office, it most likely will be in high use. Therefore, a faster model with a USB or SCSI connection and an automatic document feeder would be essential. For graphics professionals, optical density and transparency options should be considered. While all consumers will want at least 600dpi and 24-bit color depth, those who will be using heavy graphics will require rates of 30bits to 36bits.

    Sheetfed scanners are another type of scanner, which is good for itís compact design and its odd-sized use. They are generally used for less frequent scanning jobs and while they are slower then flatbeds. They are becoming less popular due to the increasing affordability of flatbed scanners.

    When photographs are the exclusive item that are going to be scanned, then a photo scanner would be the item to buy. Their image quality is excellent and it is a good alternative to digital cameras. However, even though they work very well for photographs, most do not scan photographs larger than 5 by 7 inches. The truest optical resolution would be 300 by 600 dpi for a photo scanner.

    Film scanners are good for high-end photo scanning. The alternative is using the more versatile flatbed with a transparency attachment. The transparency attachment will cost around $100. While the film scanner will give you a higher digital image, it only allows film and slides to be used. For most people, the flatbed option is the better choice.

    For those who want the portable option, business-card scanners and handheld scanners are options. Both options are pricey and have a limited use. Business-card scanners can only be used on, business cards. It works well for entering this type of data quickly and eliminating a stack of business cards from your desk. But, it cannot do anymore than a good flatbed or sheetfed scanner can do. Handheld scanners can also scan quickly, however only reads a few lines at a time and will only produce a gray scale picture. If a handheld scanner is what the choice ultimately becomes, then one that is at least in the $500 range is your best bet.

The top five scanners, as listed by CNET.com range from $90 to $140. These scanners would be most likely for home use.


 
 

    When a final purchase is about to be made, decisions should be made upon resolution, color bits, and speed. While website photographs only need 150bits due to the acceptable output for monitors, ink jets, and laser printers, a higher resolution will allow more precise scanning and image editing. The higher the resolution, the better off you are. For scanning photographs and text at least 300dpi is needed, while for more detailed graphics 600dpi would be best.

    The number of color bits determines the variety of colors a scanner is capable of distinguishing between. Before you decide to opt for the 36bit scanner, know that "most pairs of eyes canít distinguish between 30-and 36-bit output"(cnet.com). Slides and negatives work best on at least 30bits.

    Parallel scanners are much quicker than they used to be. USB scanners are not as fast, but they do have the best usable features and allow plug-and-playís to be installed. This choice depends most on what is more convenient. The time it may take to install a SCSI scanner may not be worth the advantage in speed. In general, SCSI (small computer system interface) drives "are recommended for high-performance microcomputer systems and minicomputers"(Parsons). Microcomputers are personal computers, which only contains one microprocessor chip inside. Minicomputers "carry out processing tasks for simultaneous users"(Parsons).
 
 

Bibliography

CNET. 18 April 2000. http://computers.cnet.com/hardware.
Parsons, June and Dan Oja. Computer Concepts 3rd Edition. Cambridge, MA: International Thomson Publishing Co., 1998.
ZDNET. 20 April 2000. http://www.zdnet.com/computershopper.