While somewhat shrouded in technical mystery, scanners can be a great multipurpose tool for the office. Does your web site need product shots to accompany marketing text? Do you want an electronic version of your invoice for filing and database management? Or would you like to automate the process of logging sales data into Excel? A scanner can help you with all of these tasks and more.

At its bare bones, a scanner is an optical device that breaks down images, objects, and documents into a digital format. By reading an image as thousands of individual dots, or pixels, a scanner can convert a picture into digital bits of information which are then reassembled by the computer with the help of scanning software. The file of the image can then be enlarged or reduced, stored in a database, or transferred into a word processing or spreadsheet program.

There are a few key considerations for choosing the right scanner for your needs. The most important step before diving in is to think about how you intend to use the scanner and which type of scanner fits that use. If you want to reproduce quality photographs or other images, color quality will be an important characteristic.

Whether you're looking for black and white reproduction or color, bit depth, resolution, and dynamic range are also essential to selecting the right scanner for your needs.

Of course, there are many other factors, like price and software bundles, which will make your decision that much harder. But that's why you're reading this Buyers Guide.

Scanner Uses

While lower scanner prices have induced many businesses to pick up yet another peripheral for the office computer, many manufacturers feel that scanners are still not being used to their full potential. A scanner can indeed do far more than simply scan a photograph, and many of its uses could go a long way to helping a small business. Here's a quick peek at some of the applications for the scanner in a business environment.

Graphics
Graphic images are an important part of many business' marketing and sales efforts. The Internet also offers the chance to display product shots, company photos, and other design elements of a business.

Scanners, like digital cameras, enable users to convert photographs, slides, and three-dimensional objects into files that can be pasted into a brochure, inserted into a presentation or posted on the Internet. Using accompanying software, these images can be edited, cropped, or manipulated to fit space and size requirements.

Data Entry
Instead of paying someone to manually enter reams of data into the computer, you can use a scanner to automatically convert the same information to digital files using OCR (Optical Character Recognition) software. In conjunction with the software, a scanner reads each page and transfers the text to any number of programs.

A form letter can be saved to a word processing program, sales figures to a spreadsheet, even a brochure to web-editing software. Top of the line programs boast accuracy rates of 99 percent, and most scanners include some type of OCR software.

Digital Files
In an effort to digitize his company, Bill Gates reportedly collected every paper-based form at Microsoft to examine how communication and information were distributed across departments. After filling numerous three-ring binders with thousands of documents, he took steps to eliminate the flow of paper from desk to desk.

If the clutter of your office is keeping your business from running smoothly, a scanner can help to create electronic filing cabinets for everything from invoices to expense reports. Forms can be reproduced online, and searchable databases can provide relevant information in seconds.

Scanner Types

While all scanners are designed for the same purpose - creating a digital reproduction of an image or document - scanners come in a variety of shapes and sizes designed to perform different types of tasks. Before worrying about technical specs or reproduction abilities, your first consideration should be what type of scanner best suits your needs. Here is a brief rundown of the three major types of office scanners and the functions they serve.

Flatbed
The easiest way to understand how a flatbed scanner operates is to imagine the top of a copier sliced off its base. Essentially, a flatbed scanner consists of its own base, with a flat piece of glass and cover just as is found on most copiers.

The scanning component of flatbeds runs over the length of the image in order to gather data. Flatbeds are particularly useful when a user needs to scan more than single page documents. Pages from a book, for example, can easily be scanned without having to copy each page individually first.

If you plan on scanning objects you'll want to focus on flatbeds. By placing a white sheet of paper over a bouquet of flowers a scanner can reproduce what appears to be a stock photo onscreen. Flatbeds do have a large footprint - they take up a lot of desk - so if space is a concern you may want to consider a different type.

Sheetfed
If you know that you won't be using your scanner for anything other than sheets of paper, a sheetfed scanner may be your best bet. Unlike flatbeds, the scanning component of sheetfeds is stationary while the document being scanned passes over it's 'eyes' - much like a fax machine. Usually only a couple of inches deep, a sheetfed scanner can easily fit between a keyboard and monitor.

Sheetfeds usually work best in conjunction with an automatic document feeder for large projects. While pictures and other documents smaller than a full page can be scanned using a sheetfed scanner, a flatbed is usually a better option for such tasks. Sheetfeds have been known to bend pictures and reproduce less than quality images.

Slide
Slides, because of the resolution needed to accurately reproduce very small images, do not work well in conjunction with flatbed scanners and an entirely different scanner market has been created as a result. Slides are usually inserted into a tray, much like a CD tray on your computer, and scanned internally.

Most slide scanners can only scan slides, though some newer models can also handle negative strips. If you plan to occasionally scan slides as well as other documents, some flatbed scanners have a magnified portion of their glass plate for scanning slides.

Key Components

Choosing the right scanner involves a number of different criteria, none more important than bit depth, resolution, dynamic range, and color. While the reason for buying a scanner and what you intend to scan are key decisions to consider, these four components will affect the quality of a scan regardless of how it is used in the office.

Bit Depth
When a scanner reads an image, it breaks down what is read into small dots, or pixels. Based on the quality of the machine, a scanner can record varying amounts of information about each pixel. The amount of information that the scanner can remember about each pixel is commonly referred to as bit depth.

A scanner with a bit depth of one can only distinguish whether a pixel is white or black, with each increase in bit depth representing an ability to record more details about an image's color or gray scale.

For black and white scans, a 12-bit scanner will usually provide adequate reproduction of over four thousand shades of gray. Bit depth for color scans can be broken down by how many bits the scanner can process for each primary scanning color - blue, red, and green.

An eight bit scanner can identify 256 colors for each pixel; a 24-bit scanner can reproduce 16.7 million colors. For most business purposes, a 24-bit machine is sufficient.

There are also scanners on the market at 30- and 36-bit depths, which is more color than the human eye can distinguish. While most software systems today cannot accurately process the billions of colors that come with such high bit-depths, the extra information helps to clean up images that may be affected by noise or other losses in the image transfer. In turn, those seeking the highest quality of color reproduction should look into 30- or 36-bit depths instead of 24.

Resolution
Resolution measures how many pixels a scanner can assign to any given image or document. Most scanners start at about 300 x 300 dots per inch - in other words, the scanner reads 90,000 pixels per square inch for the image being scanned. When a scanner reads an image it makes two passes, first down the document and then back up it.

Sometimes a scanner's resolution has two different figures, like 300 x 600, which indicates the scanner stops more often on its vertical pass than its horizontal run. Though this may improve the reproduction process slightly, the smallest number in the resolution description should always be considered the most reliable indicator of quality.

Some scanners list two types of resolution, optical and interpolated (or enhanced). Optical resolution measures the true number of pixels, with a larger resolution equaling a higher quality reproduction. Interpolated resolution uses mathematical computations to increase the number of pixels scanned.

In plain terms, interpolated resolutions average two pixels side by side to create a third pixel that would theoretically equal the color of a pixel between the two dots. In effect, the scanner guesses at what pixels would look like if they were squeezed in between the pixels already being scanned. For most purposes, optical resoutions are a more reliable indicator of a scanner's true resolution capacity.

There are generally accepted minimum resolutions for different scanning tasks. For images that are destined for the printer, the optimal resolution is twice the linescreen (lines per inch) of the printer. Most magazines have a linescreen between 130 and 150 lpi, so resolutions of 260 to 300 dpi should be sufficient for high end materials.

For laser printed images, most high end desktop printers have a linescreen of around 100 lpi, so resolutions of 200 dpi should be sufficient. Computer screens have low resolution outputs and images meant for the web can be scanned between 100 and 150 dpi. For OCR, 300 dpi is the standard resolution level.

Dynamic Range
If you are faced with two scanners that match each other in bit depth, resolution, and price, dynamic range may set one apart from the other. Dynamic range is similar to bit depth in that it measures the ability of the scanner to reproduce tones. It is measured on a scale from 0 to 5, with 0 representing absolute white and 5 representing absolute black.

Most standard color flatbeds have a dynamic range between 2 and 2.5. Unless you need to have perfect color reproduction, this amount should meet your scanning needs. Higher end flatbeds can get up near 3, after which professional drum scanners are needed for exact prepress reproductions.

While dynamic range should not be thought of as a straight grade of a scanner's ability, it is a useful tool for comparing scanners with similar specifications.

Color
Another factor in your decision should be whether you will be scanning black and white and/or color images. This seems obvious, but the cost of color and black and white scanners ranges considerably, and if your intended use of the machine does not include reproducing color images, it would be prudent to focus on the key differences between the two types of scanners.

If you are planning on using your scanner solely as a data entry tool, you are best off focusing on the black and white market. As with color scanners, bit depth plays a key role in determining the quality of the machine.

A scanner with a bit depth of one can tell the difference between black and white and can handle scanning simple documents for OCR purposes. A bit depth of 12 can identify 4,096 gray scales and should be more than sufficient for the most complex black and white image.

If color is the key to your scanning needs be prepared for differences from the original image to the screen and printer. Because of different settings among various computer components, an image's colors rarely remain the same through the entire reproduction process.

Color calibration software can help align the differences by matching the color definitions of each device. Exact color matching should only be an issue for high-quality prints or other professional reproductions. In most cases quality color reproduction is adequate if exact color reproduction is not possible.

Prices for scanners have dropped considerably in the last few years as technology has improved. Flatbeds can now be found for as low as $50, and generally most office needs can be met by flatbeds under $250, though prices go as high as $2,000.

Sheetfed scanners are also being offered at bargain prices, retailing between $100 and $225 from most manufacturers. Slide scanners are a bit more expensive, coming in at the $350-$500 range and beyond.

Software Bundles
Almost all scanners come bundled with different types of scanning software. Though bundles vary by scanner and price, packages usually include a driver program, color calibration software, and applications like OCR or image-editing programs. Driver programs enable the computer and scanner to communicate and operate off of an industry standard known as TWAIN.

For color calibration programs and other applications such as OCR be sure to check the software versions. Manufacturers sometimes bundle bare bones software packages that force you to upgrade in order to take advantage of the full potential of the program. With the right software, a scanner can also double as a copier or fax machine. Manufacturers usually offer different types of bundles - be selective and choose the package that best meets your scanning needs.

Connections and Requirements
Don't forget about your computer when choosing scanners, as the requirements of certain scanners could exceed the capabilities of your machine. For example, you'd be stuck when your scanner needs 64MB RAM and your computer only has 32MB. Also consider the ports on your computer and what connections are required by a scanner.

Most scanners can be connected by USB, SCSI, or parallel ports, but there is a definite speed difference among the three. SCSI and USB ports are much faster than the more common parallel port. If your computer doesn't have a SCSI or USB connection, you might want to consider purchasing an adapter card to keep the traffic from scanner to computer running smoothly.

Automatic Document Feeders
If you are planning on using your scanner for large data entry projects, an automatic document feeder (ADF) should be high on the list of required add-ons. ADFs substitute for manually scanning individual pages.

If data entry is your intended use for a scanner, also inquire about scanning speed and whether OCR software is bundled with the machine. Another interesting add-on is a transparency adapter which enables the scanner to read transparencies and film negatives.

Copyright Issues
Deciding the legalities of making digital reproductions can often be a thorny issue. If you plan on scanning images or materials that were not produced by your business, you should look into copyright rules and regulations. For more on copyright information, check out Copyright Concerns in our Articles section.