Fujitsu Plasmavision SlimScreen PDS-6101 high-definition plasma display Calibration
With a DVD input, the Fujitsu PDS-6101 produced approximately 525 lines of horizontal resolution using the AVIA test DVD, and responded crisply up to 6.75MHz, DVD's resolution. Overscan measured 0% top, 1.5% bottom, 2% left, and 2% right. The geometry and convergence were essentially flawless. Both the color-bar and sharpness patterns were outstandingly sharp without apparent ringing. Video noise was insignificant. Black-level retention (a different issue from black level itself or black-level detail) was very good, and the black level was visibly consistent from the center of the screen to the corners, as judged with the PLUGE and color-bar patterns on the Video Essentials DVD. The gray ramp, however (VE, chapter 18-6), displayed the subtle banding that has been characteristic of every plasma we've seen, a result of the current digital bit-depth limits of these displays. This phenomenon can also cause posterization or false contouring (see review).
The 61-inch PDS-6101, like the 50-inch PDS-5002, does not provide ready access to a service menu, so the only gray-scale adjustments available to us were those on the user menu—that is, overall adjustment of red, green, and blue, but no separate control of the top and bottom of the brightness range. The adjoining figure shows the Warm setting and the final calibrated User setting. (The Cool setting measured about 10,000 kelvins, Standard averaged around 8500K.) While the Warm-setting measurements look reasonable as judged by the kelvin values—even slightly better, perhaps, than the calibrated User setting—they were off considerably from the desired point of D6500, with a strong green shift. Remember, 6500K describes a line on the CIE color chart, while D6500 is the specific point on that line we're aiming for. While the final calibration produced kelvin numbers very similar to the Warm results, in fact it resulted in readings much closer to true D6500 across the board.
But it takes more than D6500 calibration numbers to produce accurate colors. You can be dead-flat D6500 across the brightness range, but if your phosphors (or other color-defining devices, in the case of displays such as DLPs and LCDs, which don't use phosphors) are wrong, the colors won't be accurate. Our measurements showed the Fujitsu's red to be reasonably correct, despite a subjective orange shift on some material. Its blue was acceptable, shifting slightly toward greenish-blue—which was not visibly noticeable. But its green was shifted strongly into a deeper green than the standard calls for. This may have been the cause of the iridescent bright greens I sometimes saw. To be fair to the Fujitsu, unusually vivid greens are a common characteristic of plasma displays. They aren't necessarily unpleasant (bright, backlit foliage appears most affected—paler shades of green often looked fine), but they're still inaccurate.
The Fujitsu PDS-6101's measured contrast was consistent with what I saw with images, and with my much more favorable response to the 50-inch PDS-5002. While the latter was no longer on hand, its contrast numbers were. But first it must be made clear that our measurement conditions reflect real-world use. The Contrast, Brightness, Gamma, and gray scale were set to where, in our judgment, they produced the best overall picture quality (see below for more on this), not in the positions that produced the most impressive contrast numbers. Manufacturers' specs for contrast will almost always be higher than our measurements. The differences reflect different setup conditions. The settings that produce the most impressive contrast numbers are not likely to produce real-world video images that a critical viewer could live with.
All the contrast numbers here were rounded off to the nearest whole number. The readings were made using a precision spot-reading light meter, the Minolta LS-100, set to read in foot-lamberts. First I measured the contrast, comparing a full white field against the black produced by an open input. The result was 82 (436). Next I compared the output in the center of a 100 IRE window with an average taken midway in the black field around it, producing a contrast of 117 (538). Finally, comparing the 100 IRE white window with open-input black resulted in a value of 156 (926).
The numbers in parentheses in the above paragraph are the contrast measurements made on the 50-inch Fujitsu PSD-5002 under the same conditions. The measured differences between the two displays were dramatic—a factor of 5-6:1 in favor of the smaller screen. But the subjective contrast differences with real video program material, as contrasted with test patterns, while definitely visible and significant, were much smaller. I confirmed this with a brief visit to a local dealer who just happened to have both displays set up side by side, driven by the same HD source: a DirecTV demo loop. I set the video controls on both sets to provide a good subjective match and produce the most pleasing picture possible under the conditions. Judging deep blacks was not possible with the generally bright program material and well-lit showroom, but the 50-inch set did look punchier and more 3-dimensional. These qualities are consistent with the 50-inch set's better contrast and greater subjective sharpness at a fixed viewing distance.
While we don't usually provide the actual settings we used for viewing a set under review, I'll do so here. If you wish to try these settings in a showroom or at home, keep in mind that the results could be affected by minor differences of individual samples, not to mention the baseline settings in some possible hidden factory setup menu—settings that might change during a production run. The viewing conditions, too, are a factor. The settings here produced the best result with our sample in a well-darkened room. Because of those possible set-to-set variations, these numbers may not produce exactly the same picture I saw, and are therefore no substitute for careful on-site setup and a professional calibration.
The following settings, used for HD and DVD on the PDS-6101, produced a peak white of about 21ft-L, though some minor alterations in the standard video settings (Contrast, Brightness, Color, Sharpness) were required with different program material: Red 245, Green 217, Blue 185, Gamma Fine, Contrast -7, Brightness -5, Color -4, Tint 0, Sharpness -8, and Noise Reduction as required by the program material. Interestingly, the Standard gray-scale setting worked much better than the calibrated User setting with NTSC broadcast material from the Video or S-video inputs, perhaps because of different settings in an inaccessible sub-menu, a color-decoder issue, or an idiosyncrasy in the NTSC tuner used (from a lowly VCR).—TJN