Note: In the following plasma panel display reviews, you'll notice that there is a significant discrepancy between the level of brightness claimed by the manufacturers (from 250 to 350 nits) and the brightness I was actually able to measure (between 70 and 80 nits). By way of explanation, more than one manufacturer told me that the claimed brightness on these displays can only be produced when the units are partially disassembled (!) -- that is, when the front glass is removed and a small "peak" portion of the screen is measured.
This may be true, but I dare anyone to try it.
Though most plasma manufacturers make great claims about brightness, I don't think they're telling the truth. Given the basic fluorescent light-emitting mechanism, I'm not even sure it is possible for plasma displays to get much brighter than they are today -- much less meet the manufacturer's claims. Bigger displays with more resolution and better color saturation are possible, but I doubt plasma manufacturers will ever achieve the levels of brightness they're bragging about.
To allow for comparison of a plasma screen's brightness to that of other large-screen displays, I have calculated the equivalent lumens from the measured nits (the unit of measurement used for the brightness of non-reflective surfaces). It's also worth noting that even though plasma displays are not very bright, their high contrast ratios, wonderful color saturation and effective anti-reflection coatings allow them to perform well in most ambient lighting conditions.
Pros: Good contrast and uniformity with excellent video performance. Represents a tremendous improvement over previous Eiki plasma displays.
Cons: Low color saturation and weak light output. Poor SVGA conversion.
Size: 3.52 cubic feet (5.9 inches thick).
Weight: 87 pounds.
Display size and resolution: 42 inches, 852 x 480 RGB pixels.
Measured brightness: 117 ANSI* lumens (77.6 nits).
Measured contrast: 149.6-to-1.|
Video compatibility: Accepts most video sources up to SVGA.
Connections: One each of computer data, S-VHS and composite video inputs. One 3-RCA jack component (DVD) video input and one set of RCA jack stereo audio inputs. One RS-232 control input. No monitor or audio outputs.
Speakers: Two 2-watt, built-in speakers.
Accessories: Includes IR remote.
Eiki claims its new plasma display (OEM'ed from Fujitsu) produces 300 nits (or candelas per meter), with a 15 percent average picture level (APL). According to Eiki, APL means something similar to "peak brightness." To produce 300 nits, a small square measuring 15 percent of the screen's total area is supposed to be operated at full white. But my row-by-row measurements show that the Eiki plasma produces only 77.6 candelas per meter on average -- a long way from 300 (the discrepancy I mentioned above).
Still, I measured the ANSI 16-point contrast ratio above 149-to-1 -- which represents a tremendous improvement over earlier Fujitsu plasmas. Even with a brightness less than the average TV set, the Eiki's high contrast ratio and anti-reflection-treated front glass allowed me to enjoy a clear image under "normal" ambient lighting conditions.
The corner brightness of this unit also measured much higher (97.2 percent) than the 80 to 90 percent usually obtained from the best three-panel projectors. And, unlike most rear-screen projection systems, plasma displays look the same regardless of the viewing angle. To be sure, even lumination across the entire screen and a wide viewing angle are two of the primary benefits of plasma technology.
The Eiki PLD-42UE's color saturation was a little better than I expected; I measured 15.07 units of color saturation. This is better than the color saturation of a cheap one-panel LCD projector (or any one-chip DLP unit), and it even exceeds some CRT computer monitors. But it doesn't compare with the saturation levels achieved by the best three-panel LCD or three-chip DLP projectors.
Nevertheless, I found that the Eiki's white point was quite good at only 2.15 units away from the standard D65 white. The combination of a good white point and reasonable color saturation produced realistic-looking images -- at first glance. In comparison with other large-screen systems with more color saturation and better color balance, however, it was clear that the Eiki's images were missing some blue.
Except for some slightly strange colors, I liked the performance of the Eiki plasma with either NTSC video or computer-data input -- but only in VGA resolution. When the computer input was changed to SVGA, the clear image seen in VGA changed to a noisier, resized image.
I also found that static computer images seemed to dim slightly if the same image was left onscreen for a few minutes. This is due to a kind of "self-preservation" circuit. The first generation of plasma displays had a real problem with static images "burning in" to the phosphors if they were left on too long. To prevent such "permanent burn" problems, the Eiki plasma's circuits slowly reduce the brightness of static images.
NEC PlasmaSync 4200W
Pros: Good contrast and uniformity, fine video performance and impressive color saturation. A thin, 3.5-inch profile gives it a lean, clean look. Remote is programmable.
Cons: Low light output, no speakers. Poor SVGA conversion.Size: 2.13 cubic feet (3.5 inches thick).
Weight: 86 pounds.
Display size and resolution: 42 inches, 853 x 480 RGB pixels.
Measured brightness: 110 ANSI* lumens (73.4 nits).
Measured contrast: 137.1-to-1.
Connections: One each of computer data, S-VHS and composite video inputs. One 3-jack component (DVD) video input and three sets of RCA jack stereo audio inputs. One "control" input, but no monitor outputs.
Video compatibility: Accepts most video sources up to SVGA.
Accessories: No speakers (audio passes through to "external" speakers). IR remote equipped with an LCD touchscreen.
As does Eiki, NEC makes an optimistic brightness claim of 250 nits for its plasma display "module," and 120 nits after being assembled into a monitor -- but the unit yielded only 73.4 nits when measured. Because I observed a similar reduction in brightness in both the Eiki and the NEC plasma displays, I am assuming that both units' "peak" brightness measurements are about the same, whatever the manufacturers claim.
Like the Eiki, this NEC display represents a great improvement over earlier units. The NEC's ANSI 16-point contrast ratio came in above 137-to-1, and its corner brightness was much higher (95.6 percent) than the corner brightness typically seen in a three-panel projector. In truth, the NEC and Eiki units performed similarly in terms of contrast, brightness, evenness, corner brightness and viewing angle. The biggest difference was in the color quality, where NEC came out on top. The reason: Instead of relying completely on the colored light produced by electronically excited colored phosphors, the way most plasma displays do, NEC has placed tiny color filters over each pixel in their plasma to greatly improve the colors.
I measured 17.6 units of color saturation with the NEC plasma -- a value better than that found in many three-panel LCD projectors. This measured value is misleading, however, as the NEC's colors were not balanced. The reds were about right, but the blues were too weak and the greens were oversaturated. Also, the white point was a little further away from true white at 3.64 units (in the purple direction) than the Eiki's white point.
The PlasmaSync's color performance was better overall than the Eiki display's, however. With better color balance, I think that the NEC plasma can compete quite well against any large-screen system -- certainly in evenness of image and color performance.
I also liked the performance of the NEC plasma display with both NTSC video and computer data input in VGA resolution. But, as in the Eiki unit, when the computer input was changed to SVGA, the image became noisier and dimmer. No matter how much I played with the adjustments, I couldn't get a satisfactory SVGA image: some crawl and blurring remained.
The overall comparison between the Eiki and NEC plasma displays is quite interesting: They weigh about the same and have almost identical image sizes, but the NEC plasma is about 2 inches thinner. But I'm not sure what the benefit of that thinness is, since neither unit can stand up by itself without the support of a large stand.
Both plasma units also are heavy -- more than 86 pounds -- and feel somewhat unstable. Given their weight, size and cost, they're not the kind of things you want to leave on a cart where someone can bump into them. Both units can be wall-mounted, but extra care must be taken to ensure the wall mount is sturdy.
The Eiki unit is also equipped with a small (2-watt) set of stereo speakers, whereas the NEC unit is not. If you want sound with the image on your NEC, you must add a set of speakers. The audio signal on the NEC unit is amplified a bit (7 watts per channel) and passed on to external speaker connections. But as far as I can tell, the only benefit of the NEC's audio circuits (over an external amp) is the ability to control the sound level with its nifty remote control, which has its own backlit LCD screen and touch panel.
Also, the NEC remote can be "trained" to replace the remote used to control your VCR, videodisc player or other equipment. The Eiki plasma has the usual push-button remote.
William Bohannon, chief scientist at Escondido, Calif.-based Manx Research (760.735.9678), has more than 25 years of experience in the computer and projector industry. As chief scientist for Display Products at Proxima Corp. from 1989 to 1994, he developed important business relationships with several Japanese laboratories and companies. His career also includes positions at TRW, Hughes Aircraft and Kappa Systems.