V, Inc. VIZIO P50 HDM PDP (plasma) Monitor Testing and Calibration
Thomas J. Norton
On a 1080i multiburst pattern from my AccuPel HDG-3000 HD test pattern generator from its DVI output, the luminance response was visibly well down in level at 37.1MHz. The response did hold up to 18.5MHz, but appeared a little uneven at that frequency. With a 720p signal from the generator, the response was strong and clean up to 18.5MHz, with some useful response at 37.1MHz (few consumer HD sources will have much content at this frequency).
With the V, Inc. set up for its best image quality (post-calibration, with contrast and brightness set to avoid crushing either the deepest blacks or peak whites), I measured a peak, full-screen contrast ratio of 607:1 (18.33 foot-Lamberts peak white, 0.03 video black) using a 100 IRE field pattern. Using a peak white window (100IRE) instead of full a screen white pattern for peak whites, I measured a peak contrast ratio of 1246:1 (37.39fL white, 0.03 black). This is typical of PDP displays. Much like CRTs (but unlike other digital display technologies) PDPs will not produce maximum brightness with a full white screen. But if you reduce those bright areas to highlights, like bright lights on an otherwise dim or dark street, and those highlights may be far brighter. Since video program material more often than not resembles the latter situation—bright highlights rather than a peak white level covering most or all of the screen—the contrast ratio obtained with a white window pattern more closely corresponds to what you will actually see from a PDP in normal day-to-day use viewing.
The red and blue color points were very close to the HD standard, but green was too deep and rich—a common situation with digital displays. Most color decisions at the program creation end are still made using monitors with SMPTE C/NTSC phosphors, so one could argue that consumer sets should be designed to match the SMPTE C color points rather than the newer HD standard. But that conundrum—a video display that's accurate to the standard or a display that better matches sources that deviate from that standard—is a philosophical argument for another time. Fortunately, the seriousness of the deviations we're talking about here do not compromise the image to a degree likely to bother most viewers.
While the VIZIO produced pleasing color overall, there was a limit to how well it could be calibrated with its single set of service-level adjustments. While calibration did improve the measured result significantly, the numbers still show a rising response as the brightness increases (plus an odd post-calibration blip around 35IRE). The impact of this rising color temperature on the picture will be more of a psychological than visual annoyance to the video purist, and is unlikely to trouble the average viewer in the least. But I wish that the set provided color temperature adjustments at both the top and bottom of the brightness range to make it possible to more closely approach a true D6500.
Overall, however, I agree with LEU on the VIZIO. Two years ago it would have cost you $10,000 or more to get the sort of image quality in a PDP display that the V, Inc. now gives you for less than one-third that amount.