If you take a look at how a scanner works, you'll realize that nowadays there is no justification for buying the most expensive model. Here are four of the most recent ones:

• The CanoScan D1250U2 is the first scanner for general use that is compatible with the new USB 2.0 interface. In North America, this model is sold as D1250UF, which includes a USB 2.0 PCI card and an adapter unit for scanning transparencies.
• The Epson Perfection 1250 is the successor to Perfection models 1240 and 640. The 640 is still considered by many to be the best in its class.
• The ScanJet 4470C is marketed by HP as a "reliable and affordable scanner, as simple to configure as it is to use." It is supplied with a module for scanning slides and transparencies.
• The Umax Astra 4500 claims to be a speedy workhorse at a very low price. Certainly it was the least expensive model in our selection.

All four of them share an optical resolution of 1200 dpi and 48 bit color-coding, and all are USB compatible. In other words, all of them ought to be capable of producing good-quality scans at low resolution (website images) and at high resolution (retouching and enlarging photos).

In order to compare them, we timed them on the following tasks:

• pre-scanning an A4 page
• scanning a 10 x 15 cm photo at 72 (or 75), 300, 600 and 1200 dpi
• scanning a photo from a magazine at 300 dpi
• scanning a postage stamp at 1200 dpi and 2400 dpi (an interpolated resolution in this case)
• scanning an A4 photograph at 300 dpi

The test for quality consisted in comparing all the previous results, as well as:

• evaluating the color rendering of the optical system, based on our test patterns
• considering the scanners' ability to scan 3D objects