Scanners are hardly considered cutting-edge tech these days, but every now and then some company comes along and surprises me. This time, it's HP, with its six-channel Scanjet G4000 series. Like the proverbial "overnight sensation," the G4000 has been in development since 1998--awaiting, I suppose, the price drops and advances in optical engineering necessary to make it both feasible and practical.
The basic idea is simple, if somewhat inelegant. A scanner generally uses a single light source that shines through (in the case of slides and negatives) or reflects off of (prints and objects) an original; the light then passes through red, green, and blue filters before being recorded by a sensor. The light source, the sensor, and the filters each have a specific spectral response--the characteristic ways in which they emit or respond to light of varying frequencies and intensities--which combine to determine the color gamut of the scanner. Typically, there are gaps in the gamut because of limited response at certain light frequencies and/or intensities. HP addresses these gaps by adding a second light source tuned to work with the same sensor and filters, but with an overall spectral response that complements that of the first source in the same frequency/intensity ranges. In other words, it aims to capture the areas of the red, green, and blue spectra that it can't capture with the first lamp. The scanner makes two passes, one with each source, then combines the 96 bits of data--two sets of red, green, and blue, for six channels--into a 48-bit file.
The G4000 series includes two models: the G4010, a 4800dpi flatbed designed for scanning prints, and the higher-end G4050, which adds a built-in transparency adapter as well as hardware-based dust-and-scratches removal. The G4010 comes in a boring business white, while the G4050 is available in a slightly snazzier, printer-matching black and silver. After the huge Epson Perfection V700, the 4.3x11.9x20-inch (HWD) G4050 seems amazingly compact, and overall I find it sturdy and well- designed. Four big, inset buttons on the lid allow you to scan directly to PDF or to the printer, and transparent or reflective materials can go straight to a file.