Light fantastic

Introduction

Scanners are one of the most desirable extras for a Mac. Along with fancy inkjet printers, scanners help people get the most from computers. Whether it’s for putting together personalized birthday cards, school homework, inputting text, or art projects, they’re unbeatable for fun and serious work. Scanners are also great for preserving old photographs. Old photos fade and crumble, and scanning them on to a Mac means you can keep them forever. Whether you want to just store pictures in digital form, or reproduce them on inkjet printers, a scanner is essential. The difference between pro and consumer scanners has narrowed over the years. To the casual observer, traditional measurements – resolution, for example – might indicate there’s no difference, but this is a mistake. The disparities are threefold: first, the quality of the scan; second, the ability to scan transparencies with a bright-and-even light; and third, the software. Resolution Scanner resolution is probably the most-quoted measure of quality, but in fact, it’s a measure of quantity. It’s the number of pixels per inch that are captured. Many people think more is better, but it depends on how many pixels per inch are needed. One thing you can’t do is look to an inkjet printer for guidance. Inkjet printers claim resolutions of up to 5,760dpi, which could suggest you need a scanner to scan at that resolution. However, the printer resolutions refer to the number of droplets of ink used to output an image. This is different to the input resolution, because each pixel of the file is made from a number of droplets. The droplets are counted as dots per inch, though technically they shouldn’t be considered pixels. The important point is that you don’t need super-high resolution unless an image is destined for billboards. The resolution generally needed is 300dpi. This is enough to print out on any printer – from inkjet to professional press. In Macworld, we use 300dpi images, which more than suffices. The only reason to scan a higher resolution is if you need to increase the size of an image. For instance, a photograph scanned at 600dpi can be printed at twice the size of one scanned at 300pdi. For four times the size, you would need 1,200dpi, and so on. Original photographs can be blown up only so far before the image’s grain is noticeable. Transparencies When scanning transparencies, the image size often needs to be increased. A 35mm slide can be scanned on some of the models tested, but it’s best to spend the extra cash on a higher-end model – see next month’s Test Centre. Transparent media needs to be illuminated from behind, so professional scanners have a bright light that tracks down the image with the scanning head. The light increases the density range – the difference between light and dark areas in the image – that can be seen by the scanner. Consumer models tend to have static lights to backlight transparencies, but these are less bright and the results not as good. The scans they produce are usable, but compared to the results from a pro scanner or a specialist slide scanner, they fall short. Non-digital camera enthusiasts should consider investing a little extra for transparency scans. Software Pro scanners have notoriously complex software, and so consumer scanners should be simple to use. Integrated software makes scanning easy for novices and those who just want to push a button to scan, not read a book about it first. The scanners on test have differing levels of automation and software bundles. Some models have multiple buttons so you can scan directly to an email, printer or other applications. OCR (optical character recognition, which converts scanned text to a format readable by word-processing software) is great when it works, although it seems this technology has improved little over the past ten years. Mac OS X The Mac market is firmly in OS X territory now, so compatibility with it was supposed to be a minimum requirement for our tests. This isn’t as simple as you might think. Drivers are not available for all models, though OS X’s Classic mode (OS 9.x) offers a temporary solution. Fully OS X-native drivers and software are available only for a handful of models (the HP ones), while some others have public beta drivers. Having tried to use some beta drivers, I’d say wait until the companies have completed testing before choosing a scanner. One of the beta drivers caused havoc on our lab computers, so it just isn’t worth the risk. OS X-friendly scanners get extra points, or rather points were deducted for non-OS X drivers. During the life of a scanner you’ll probably use OS X – if you don’t already. If a manufacturer still hasn’t finished the drivers, you can assume that its forward thinking – or at least its development time – is poor. If future versions of OS X prove to be incompatible with a scanner driver, it’s reassuring to know that the scanner manufacturer is likely to be quick to fix any issues. TWAIN While suites of OS X scanning software are a way off from many manufacturers, a few offer TWAIN drivers. These allow scanners to be used from various applications, such as Adobe Photoshop, or as a stand-alone application. This is basic driver software, rather than the full-software bundle. A TWAIN driver isn’t inherently OS X compatible, but it is the first component of a suite that would need to run natively. This is why some manufacturers have released – or are about to – the driver. FireWire Some FireWire scanners are beginning to emerge. In theory, FireWire is faster than USB, with its bigger bandwidth. In practice, FireWire is slightly faster – but not massively. This is because the speed is set as much by the scanning hardware as the interface. Getting a faster interface is good – and FireWire is theoretically 30 times faster than USB – but don’t expect scans 30 times quicker than a USB scanner.
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