Scanners offer a simple, cheap way to digitize images for printing, editing on your computer, or sending via e-mail.

Continuing improvements in scanners have made it cheaper and easier to turn photos into digital images that you can enhance, resize, and share.

And flatbed scanners are no longer restricted to printed originals. Our tests show that the best flatbeds are a match for pricey film scanners when it comes to digitizing slides and negatives. That's no small accomplishment, reflecting improvements to the resolution that new scanners deliver and better accessories to hold film strips or slides securely for sharp, accurate scans.

WHAT'S AVAILABLE

A number of scanners come from companies that made their name in scanning technology, including Microtek and Visioneer. Other brands include computer makers and photo specialists such as Canon, Epson, Hewlett-Packard, and Nikon.

Which type of scanner you should consider—flatbed, sheet-fed, or film—depends largely on how you will use it.

Flatbed scanners. More than 90 percent of the scanners on the market are flatbeds. They work well for text, graphics, photos, and anything else that is flat, including a kindergartner’s latest drawing. Flatbeds include optical-character-recognition (OCR) software, which converts words on a printed page into a word-processing file in your computer. They also include basic image-editing software.

A key specification for a scanner is its maximum optical resolution, measured in dots per inch (dpi). You’ll pay more for greater resolution. Price: less than $100 for 600x1,200 dpi; $100 to $500 for models with greater resolution.

Film scanners. Serious photographers may want a film-only scanner that scans directly from an original slide (transparency) or negative. Some can accept small prints as well. Price: $400 to $800.

IMPORTANT FEATURES

While the quality of images a scanner produces depends in part on the software included with it, there are several hardware features to consider.

You start scanning by running driver software that comes with the scanner or by pressing a preprogrammed button. Models with buttons automate routine tasks to let you operate your scanner as you would other office equipment.

On some models you can customize the functions of the buttons. Any of these tasks can also be performed through the scanner’s software without using buttons. A copy/print button initiates a scan and sends a command to print the results on your printer, effectively making the two devices act as a copier. Other button functions found on some models include scan to a file, scan to a fax modem, scan to e-mail, scan to Web, scan to OCR, cancel scan, power save, start scanner software, and power on/off.

You can also start the driver software from within an application, such as an

image-editing program, that adheres to an industry standard known as TWAIN. A scanner’s driver software allows you to preview a scan onscreen and crop it or adjust contrast and brightness. Once you’re satisfied with the edited image, you can perform a final scan and pass the image to an application or save it on your computer. You can make more extensive changes to an image with specialized image-editing software. And to scan text from a book or letter into a word-processing file in your computer, you run OCR software.

Many documents combine text with graphic elements, such as photographs and drawings. A handy software feature that’s found on many scanners, called multiple-scan mode, lets you break down elements into different sections that can be processed separately in a single scan. You can designate, for example, that the sections of a magazine article that are pure text go to the OCR software without the article’s graphic elements. Other scanners would require a separate scan for each section of the document.

Some flatbed models come with film adapters designed to scan film or slides, but if you need to do this often, you’re better off getting a separate film scanner.

HOW TO CHOOSE

Consider how much resolution you need. If you want to scan only printed originals, you can buy a basic scanner with 1200-dpi resolution for less than $100. That’s all you need for most same-size scans of photos, graphics, and text.

If there’s any chance you might want to scan transparent material or blow up portions of an image, you’re better off spending a little more for higher resolution. We tested models with 2400 dpi or higher for $100 to $250. You can always lower a scanner’s setting to the resolution required—and you should, to keep scan times short and file sizes small.

For scanning film and slides, 2400 dpi is the minimum you’ll need, but you’ll get better results with 3200 or 4800 dpi. In our tests, the 4800-dpi models produced the best scan quality with transparent originals. The higher resolution allows you to capture more detail when enlarging a 35-mm original or zooming in on a portion of an image.

When comparing specs, focus on native optical resolution. "Interpolated" or "enhanced" resolution comes in handy for scanning line art.

Consider color-bit depth for film. For enlarging prints or scanning negatives or slides, the greater the color-bit depth, the better the scanner can differentiate among subtle gradations of shading: 24-bit (8 bits per color channel) is basic; 48-bit (16 bits per channel) is better.

Consider a multifunction unit. If you won’t make heavy demands on a scanner (for instance, you don’t need to scan film or slides) and you need a general-use printer, especially for a tight space, a multifunction printer/scanner/copier may serve.

Choose quality and speed that suit your needs. Most of the tested scanners did very well at reproducing a color photo at 300 dpi. Those judged good produced less-crisp scans, with less-accurate colors. Fewer models did well with film.

Speed matters if you expect to be scanning regularly. In our recent tests, the fastest took about 11 seconds to scan an 8x10-inch photo at 300 dpi, while the slowest took about 30 seconds.

Don’t sweat the software. All the scanners we tested came with software for scanning, image editing, and optical character recognition for scanning text into a word-processing program. Some have software for making digital photo albums or other projects.

Copyright © 2003-2007 Consumers Union of U.S., Inc.

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