NEC SpectraView Reference 21 review
Looking at the price above, you might think NEC is committing business suicide with its latest display. But the Reference 21 is no ordinary 21in TFT. The resolution is standard at 1,600 x 1,200, but this monitor’s colour reproduction is anything but average.
The traditionally limited colour gamut of computer monitors has been comprehensively addressed in the Reference 21; while the Eizo ColorEdge CG220 and NEC’s own SpectraView 1980 were the first to cover the Adobe RGB colour space, the Reference 21’s capabilities include that space and more – NEC claims 100 per cent coverage of both Adobe RGB and NTSC spaces.
The Reference 21 is the first full-sized TFT monitor we’ve seen to use an LED backlight rather than fluorescent tubes. It doesn’t sound like a deal breaker, but LEDs give a high-end monitor a stack of advantages. Conventional TFTs using cold-cathode fluorescent tubes improved upon CRTs (cathode-ray tubes) for warm-up times, but for truly critical applications they still need up to an hour to achieve colour stability. The backlight in the Reference 21 requires no warm-up at all, partly because LEDs are simply more stable and also due to the design of this screen’s colour feedback system.
The backlight doesn’t use white LEDs, but a bottom-mounted row of about 50 red, green and blue diodes, mixed by a diffuser element to form white. This means two things: first, the native colour temperature of the backlight can be adjusted by varying the relative level of the red, green and blue elements of the backlight. This is impossible with conventional fluorescent-backlit displays, as standard TFTs adjust colour temperature in software by partially turning off the red, green or blue pixels to achieve the right balance, reducing light output. Second, the independent red, green and blue emitters mean that warm-up variations can be corrected dynamically: a colour sensor in the back of the Reference 21’s case monitors the level and hue of the backlight and adjusts itself to compensate. Consequently, NEC claims that no warm-up period is needed at all.
The final advantage of LEDs is their inherently long life – even longer than fluorescent tubes. The backlight should last forever, and the constant colour compensation feedback system promises almost no degradation with age.
NEC supplies the Reference 21 with SpectraView Profiler calibration software, which it recommends is used with a calibration device incorporating a photospectrometer rather than a less-accurate colorimeter. The interesting point about the SpectraView software is the option to calibrate using the L* gamma curve. Traditional gamma correction is based on a curve that neatly represents the brightness response of a cathode-ray tube, but LCDs have a more complex curve. L* accounts for this, leading to more accurate calibration.
Properly calibrated, the display of the Reference 21 comes closer to a print-out than any other monitor we’ve seen. Certain spot-process colours – bright orange, for instance – are still out of gamut, but Adobe RGB-limited prints are near-perfect. The human eye’s incredible sensitivity means there are still perceivable variations in skin tones and in the neutrality of monochrome images, but it’s certainly close enough for proofing purposes.
The Reference 21 is a much more convincing outing for wide-gamut displays. It’s still very, very expensive and for niche markets only, but LED backlighting gives a lot of added performance and no obvious drawbacks. If you’re serious about colour reproduction, it’s a true standard setter.