FireWire Scanners

Veterans of SCSI nightmares will be amazed and delighted to discover how easy it is to connect a FireWire scanner to a current Mac. No need to set IDs, no worrying about termination–and you don’t even have to shut down your computer to connect and disconnect them.

Two new scanners, the Epson Expression 1600 and the Umax PowerLook 1100, more than live up to FireWire’s promise not only of plug-and-play but also of speed: both scanners can transfer an 18MB scan from a 35mm original in well under a minute. Unfortunately, the scanner-control software that accompanies these pro-level scanners is woefully inadequate.

Resolving Our Differences

The Expression offers the higher resolution of the two–1,600 by 3,200 dpi, compared with the PowerLook’s 1,200 by 2,400 dpi. But the PowerLook has a slightly higher dynamic range, pulling –out more shadow detail when scanning high-contrast transparencies. When you’re scanning negatives or prints, which require far less dynamic range for adequate scanning, you probably won’t see a difference between the Umax and the Epson.

Both scanners feature asymmetrical resolutions: the lower number indicates the physical resolution of the CCD detector that actually reads the information; the higher number is obtained by stepping the scanning head in half-pixel increments. If you scan at the higher resolution, therefore, you get real pixels in the vertical dimension and interpolated pixels in the horizontal dimension. In practice, we saw obvious interpolation artifacts in 3,200-dpi Expression scans but not in 2,400-dpi PowerLook scans, and the artifacts worsened when we applied sharpening in an image editor. The Expression clearly resolved more detail at 2,400 dpi, however.

Controlling Personalities

Without good software to control it, scanner hardware is just an expensive doorstop. When it comes to scanner software, the makers of mass-market desktop scanners simply don’t get it, and in this case Epson seems to not get it to a considerably greater degree than Umax. The previous generation of Epson Expression scanners featured LaserSoft’s very capable SilverFast driver, but Epson has unfortunately chosen to develop its own driver for this generation.

Both scanners are driven by TWAIN modules that can function as Adobe Photoshop plug-ins or as stand-alone applications. Umax’s MagicScan 4.4 offers a reasonably full complement of manual controls, along with an on-screen densitometer that displays the pixel values beneath the cursor. Epson’s TWAINPro lacks a similar feature, forcing you to rely entirely on the preview. And TWAINPro’s manual controls are, in a word, goofy. The scanner industry generally agrees that a gamma of 1.0 represents linear output; Epson’s gamma values range from 50 to 500.

Out of Sync

As far as color management is concerned, neither company gets it. Photoshop has offered arbitrary RGB working spaces independent of the monitor for almost two years now, and it’s dismaying when scanners in this price range offer no obvious way to get accurate color into the application people are more likely to use than any other. Umax offers MagicMatch, which uses Kodak’s color-matching technology to let you scan to any RGB or CMYK printer profile or to CIELAB, but not to “space” profiles such as those that represent Photoshop’s RGB working spaces. Epson claims its TWAINPro supports ColorSync, but all the ColorSync button does is disable manual controls and convert from an invisible scanner profile to your monitor’s profile. If you edit an image in either application based on the preview, the scan will look completely different in Photoshop.

The one ray of sunshine is that both scanners can export raw high-bit data into Photoshop, though that process isn’t mentioned in either scanner’s documentation. Neither scanner does a particularly good job of creating a positive image from a color negative, which means you’ll have to edit those images in Photoshop.

Both scanners offer film holders for mounted 35mm transparencies as well as for larger film formats, but only the Expression offers a holder for unmounted film strips. When you use the 35mm slide tray, the PowerLook’s MagicScan locates each image without user intervention, so you can quickly create raw scans from a batch of slides. The Expression’s TWAINPro has an autolocate button, but it fails to crop the images correctly–it can lose as much as a third of the image.

July, 2000 page: 40