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REVIEWS |
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| SIX DEGREES OF ILLUMINATION | |||||||||
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| Plasma and
LCD Monitors go head-to-head by Peter H. Putman, CTS It’s hard to believe that it has been six years since I conducted the first Video Systems Plasma Roundup. During that time, there have been tremendous changes in technology and price. Consider that, in 1997–
More importantly, TFT LCD monitors are coming into their own, with the 30” barrier broken in 2001 and the 40” barrier demolished in the fall of last year. That means you will have two different technologies to choose from in screen sizes up to 42”. But that doesn’t mean that LCD and plasma performance will be equal, when all things are considered. For this year’s Roundup, I received five plasma monitors, two of which were actually integrated plasma TVs with NTSC tuners. None of them have larger screen sizes than 46” and three entrants featured Wide VGA (852x480) pixel resolution, a category where there have been dramatic price drops of late. In the LCD arena, I had a single high-resolution TFT LCD panel. In a new twist, I finally upgraded my desktop PC to include an nVidia GeForce4 display card, which allows me to send out both analog RGB and DVI signals at the same time. Five of the displays in this review came equipped with DVI inputs and I was anxious to see how each monitor would support standard DVI scan rates. I also tested these panels for compatibility with DTV (480p, 720p, and 1080i) signals connected through the DVI port. SURVEYING THE FIELD Specifications
The smallest monitor in this year’s Roundup was Philips’ 32FD9954 (MSRP), a 32” widescreen plasma design. This compact monitor also works as an integrated TV by adding the FTR9964 AV switcher, which incorporates an NTSC tuner and a bunch of switches for video and audio inputs. (For the purposes of this review, I tested the 32FD9954 as a standalone monitor without the AV switcher). There were a few entrants in the 42” category, starting with Hitachi’s CMP4201 (MSRP). This plasma monitor has a new wrinkle – an optional plug-in video card – and a native resolution of 1024x1024 pixels (yep, it’s an AliS panel). The CMP4201 does not include a DVI connection as a standard feature. NEC’s new PlasmaSync 42PV4 (MSRP) is a lower-price monitor for everything from displaying video and graphics to public display, retail, and other applications. This model offers Wide VGA (853x480) resolution, plus a gaggle of input connectors including a DVI-D interface. Panasonic’s TH-42PWD6 (MSRP) is a sixth-generation design and also offers Wide VGA (852x480) resolution. Panasonic has also moved to adopt a plug-in video card architecture, but the choices are all proprietary designs – not open standard. DVI support is not included in the basic panel. The plasma crowd was rounded out by the V Inc. Vizio P4 (MSRP), a 46” Wide VGA (852x480) product that has its roots in Japan – the original 46” design was a Mitsubishi effort and is now being fabricated in Taiwan. The P4 is also an integrated TV, but unlike the Philips entry, it has a built-in NTSC tuner. And you get a DVI connector, too. In the LCD room, NEC-Mitsubishi sent along their LCD 4000 (MSRP). It’s a 40” widescreen TFT design that works as a monitor and provides Wide XGA (1280x768) resolution (as do most widescreen LCD panels from 15” to 42”). In addition to a bunch of video and RGB I/Os, there’s also a DVI connector. OUT OF THE BOX If you are into design and esthetics, then the Philips panel is worth a look even with its small screen size. This monitor came with a curved and bowed stand that would stand out on any desk or tabletop. The Vizio P4 also had a nice brushed-silver appearance with front-panel adjustment buttons. On the other hand, the NEC, Panasonic, and Hitachi plasma monitors have that familiar “Pro AV” look with a dark gray finish. Not that there’s anything wrong with it, just that these boxes are really designed for function over form. NEC’s LCD monitor also falls into this category with a very dark frame housing. Each of the review models has some sort of support stand. Other than the elegant Philips version (which makes it hard to access the rear panel connectors, by the way), the rest of the bunch use rectangular bases that actually slide into the plasma housing and are pinned in place with machine screws. You can, of course, also mount any of these screens to a wall, truss, or grid, using supplied hardware and in some cases, optional wall-mount kits. None of the review units are particularly heavy, although you should expect to support up to 70 pounds (unless you are using the Vizio P4, which weighs just over 80 pounds). While each of the panels provides a full bevy of input connections, the hands-down winner in this category was NEC’s PS42PV4. It comes with two pairs of composite and S-video jacks, plus 15-pin and 5xBNCs for RGB and component signals, YPbPr component input with RCA jacks, and a DVI-D connector. (Do you have enough sources for a monitor like this?) Each of the review monitors has built-in audio amplifiers, ranging from a paltry 2W system on the Vizio P4 to a more robust 7-8 watts on the NEC and Panasonic plasma and NEC-Mitsubishi LCD monitors. Want more “juice”? Hitachi’s offering gives you 10 watts per channel, while the Philips monitor is a veritable “boom box” at 15 watts per channel! REMOTES AND MENUS Those readers who know me well are used to my rants about the size and function of remote controls. Apparently, a lot of small-fingered people (SFP) took over the manufacture of remotes many years back, for I have seen some designs that are all but useless due to a preponderance of tiny buttons. This year’s crop of remotes indicates that the SFPs are still in control. I liked the NEC plasma remote the best, with its now-standard baton shape and minimalist button complement. There’s enough space around each button that you are assured to activate only the functions you intend to activate! You also have direct access to any input within a group (RGB/PC, DVD/HD, Video). Panasonic’s remote could use larger buttons but also retains a wide-open layout. However, you cannot access any video input directly. You must step through them in sequence to find the signal you want. There is a direct PC input access button to take you through the menu faster. The Hitachi and NEC-Mitsubishi LCD remotes are so similar that it’s obvious they are sourced from the same manufacturer. Both are almost half as long as the NEC ‘stick’ and present a somewhat-confusing layout, with the Hitachi remote guiltier in this regard. In the Hitachi’s favor, it does allow you to directly access any of four input sources, while the NEC remote employs much slower sequential input selection. The two least user-friendly remotes belonged to Philips and Vizio. Both have a plethora of same-size, same-color buttons and it takes a bit of scrutiny to find the correct button under low lighting. It’s also easy to hit the wrong button with either remote. In Philips’ favor, its remote offers direct access to any of four inputs, while the Vizio remote requires use of the onscreen display or sequential pushes of the ‘PC’ or ‘Video’ buttons. Menus varied as much as remotes. I liked the NEC plasma menu as it was comprehensive, easy to navigate, and make adjustments and exit. Ditto the Vizio and Hitachi menus, although the Hitachi menu requires a fair amount of scrolling and secondary pages. Panasonic’s adjustment sub-menus disappear from the screen much too quickly; you need to configure the menu for them to stay on longer. The NEC-Mitsubishi LCD and Philips menus are very basic in terms of functions and require a lot of button pushing and navigation to get around. Oddly enough, you can only adjust white balance on the NEC-Mitsubishi LCD monitor while in RGB mode; there is no such function when viewing video (which is REALLY when you’d want to adjust white balance!). Philips provides three preset color temperature settings (none of them all that accurate), as do the Hitachi, Vizio, and Panasonic monitors. But NEC goes them all better with four presets on their 42” plasma. Want to dial in your own color temperature? You can set RGB drive on the Vizio, NEC-Mitsubishi (in RGB mode only), Hitachi (only two color channels available, the third must stay set at 255), Panasonic (red and blue only), and RGB drive and bias on the NEC plasma monitor. Gamma settings are also available on the Hitachi, Panasonic, NEC plasma, and Vizio displays. Depending on the model you’ve picked, you have a varying degree of control over aspect ratios. In RGB mode, each one of the test monitors except the Vizio would allow me to size PC signals from VGA (640x480) to XGA (1024x768) as either 4x3 or 16x9 images. The Vizio P4 shows all signals above 640x480 as either a stretched widescreen image or as a 1:1 pixel map. The latter option means the image is still widescreen and you only see a portion of it. You can pretty much count on having an ‘auto pixel align’ function on all of these monitors, as well as being able to adjust horizontal and vertical image size and position. Of course, you will not be able to make these adjustments to HDTV signals (1280x720 and 1920x1080), only to SDTV (480i/p, 576i/p) and some oddball widescreen PC formats. There are other menu gimmicks and gadgets. The NEC-Mitsubishi monitor lets you capture any image as a still frame, and also offers Picture in Picture (PiP) modes. Ditto the Vizio P4. Panasonic and NEC allow you to configure their plasma monitors into a plasma datawall, assigning and mapping PC and video signals across them as you wish. Most importantly for plasma users, you’ll be able to activate one or more menu functions to extend plasma life and prevent burn-in on all but the Philips monitor. (Burn-in isn’t a problem with LCD technology). Hitachi has three pre-selected life modes, one of which actually makes the panel brighter (oddly enough), plus picture orbiter and reverse mode. You can also ‘flash’ the screen full white to eliminate residual pixel charges. NEC also provides both picture orbit and reverse functions while adding an auto brightness control along with the full screen white ‘flash’. Panasonic offers picture orbiting under the quaint menu function name of “wobbler”. You can also reverse the image and go to a low power mode. Instead of an all-white screen-clearing mode, Panasonic provides a thin white bar that ‘wipes’ across the screen several times to clear residual charges. In contrast, the Vizio P4 provides picture orbiting and reverse functions only. ON THE TEST BENCH
This year’s performance tests were a bit more rigorous than in the past. For one thing, I now sweep every “HDTV-ready” display for frequency response. It’s one thing to say your plasma or LCD TV “has enough pixels to show 720p HDTV”, or is ”close enough to 1920x1080i”. But it’s quite another to actually pass all of that data through to the screen! A 1920x1080/30 signal requires about 93 MHz of bandwidth, while a 1280x720 signal wants close to 83 MHz. In my experience, you’ll generally see sufficient bandwidth on the RGB inputs of any plasma or LCD monitor, but the component video inputs are another story. Using an AccuPel HDG2000 HDTV test pattern generator and a luminance multiburst test pattern, I found that none of the review monitors could pass a 37.5 MHz signal in either 720p or 1080i mode, and many of them had problems with a 18.5 MHz burst. That indicates choked bandwidth, and determines how crisp and detailed your HD images will be – native pixel counts notwithstanding. The best frequency response in 720p mode belonged to NEC-Mitsubishi’s LCD4000, Panasonic’s TH-42PWD6, and V Inc.’s Vizio P4. Philips’ 32FD9954 had too much noise and instability in the 18.5 MHz burst pattern, while the Hitachi and NEC plasma monitors exhibited banding at that frequency. For 1080i response, none of the panels had an edged over the other – the 37.5 MHz bar showed up gray on all of them, and response at 18.5 MHz was about the same. Exceptions: The Philips monitor couldn’t pass anything over 12.4 MHz, and the Vizio P4 exhibited sync tearing and instability with a 1080i test image. On to other tests! As usual, each monitor had its RGB and video inputs calibrated for best grayscale (not brightest image) using the Video Essentials DVD, RGB test patterns, and the AccuPel generator. Where multiple modes of contrast and brightness were available, I elected to use ‘standard’ or ‘normal’ presets with gamma set from 2.2 – 2.4. Among all monitors, top brightness scores were awarded to the NEC-Mitsubishi LCD4000 with an amazing reading of 330 nits. Of course, when you don’t have or need a picture brightness limiting circuit, you can pull off a stunt like that. In the plasma grouping, overall brightness honors went to the Vizio P4 with a full-screen-white reading of 146 nits. This number easily outdistanced the rest of the field, although in fairness I should say that many of the other panels have more aggressive automatic picture level (APL) controls. Switching to 4x3 mode resulted in a reading of 83 nits on Hitachi’s CMP4201, edging out NEC’s PS42VP4. (The Vizio P4 doesn’t support the 4x3 PC sources used in this test). Contrast scores were up across the board this year from last and the competition was closer than ever. Even so, Panasonic once more held off all challengers with an impressive reading of 508:1 ANSI (average) and 649:1 peak, using a 16x9 checkerboard test pattern. How’d they do it? Try an average black level reading just shy of .2 nits! NEC’s PS42VP4 came in second with readings of 332:1 ANSI and 389:1 peak, while Hitachi had a strong runner-up showing at 284:1 ANSI and 413:1 peak. Credit their black levels readings of .34 and .39 respectively for that strong showing. NEC-Mitsubishi’s LCD monitor broke the contrast tape at 136:1 ANSI and 169:1 peak, which might not sound like impressive numbers for a plasma monitor but are very respectable for LCD imaging with its higher ‘black’ levels.
For best white balance, it was hard to beat the Panasonic entry. As you can see from the grayscale tracking chart, color temperatures were all over the place at different luminance levels. Only Panasonic’s TH-42PWD6 and NEC’s PS42VP4 managed to keep within reasonable bounds, producing images with a maximum shift at or less than 1000 degrees K from black to white. NEC-Mitsubishi’s LCD4000 didn’t do too badly once it worked its way up the 11-step grayscale to higher luminance levels. But that first step was a doozy with readings in the 10000K ranges! You can get nice white balance out of this monitor, but not with video sources – the RGB drive menu just isn’t available. AUTOSYNC TESTS Insert Table 4 here – Sync Tests
There has to be some irony in that the best performer in these tests (Vizio P4) will not allow you to size 4:3 PC signal sources correctly if they exceed 640x480 pixels in resolution. More’s the pity, for the P4 got 22 of the test RGB signals lined up correctly without any further tweaking and 1 additional signal with some fiddling in the menu. In another surprise, Philips’ 32FD9954 was the second best performer, figuring out 21 test signals correctly on its own – and even showing the 4x3 signals in the correct aspect ratio. Both NEC’s PS42VP4 and Panasonic’s TH-42PWD6 were able, with some futzing around, to display a total of 24 of the 25 test signals, but the Panasonic monitor could only set up 11 on its own. The Hitachi and NEC-Mitsubishi monitors also did well in this test, provided you didn’t mind going into the set up menu and tweaking the clock and phase. (In case you were wondering, all six monitors were able to sync up to 480p, 720p, and 1080i signals in the RGBHV format with no additional help from me.) As far as DVI compatibility goes, the Philips, Vizio, and NEC LCD monitors had varying degrees of success with basic PC rates (800x600, 1024x768, 1280x768) and DTV rates. While all three monitors handled 480p and 720p just fine as a DVI signal, the LCD4000 choked on 1920x1080i and NEC’s PS42VP4 identified the 720p and 1080i DVI test signals simply as “Illegal”. (In speaking with NEC, I determined that might be due to the lack of support for High Definition Copy Protection on the PS42VP4.) V Inc.’s Vizio P4 was highly amusing to watch during these tests. It had a hard time identifying several DVI signals correctly, branding 1280x720 DVI as “1280x1024, Out Of Range” and identifying a subsequent ‘true’ 1280x1024 signal as “1360x768”. In fact, many of the RGB and HDTV test signals triggered an “Out Of Range” OSD on the P4 while simultaneously displaying just fine. Apparently, this plasma monitor is smarter than it looks. IMAGE QUALITY The final test was to put the panel through a battery of image quality tests with signal sources from DVD, my desktop PC, assorted D-VHS tapes of material recorded off-air, and Joe Kane Productions’ new Digital Video Essentials (available in both 720p and 1080i D-VHS format). Good white balance was harder to attain on the Vizio and Philips plasma monitors, even though the P4 has RGB drive adjustments. The problem is that neither monitor tracks a neutral color of gray very well, and both suffer from high black levels (along with the 32FD9954) in the .7 to .8 range. (That’s four times the average level I recorded from the TH-42PWD6.) Composite video decoding and interlaced motion compensation was best on the Panasonic and NEC plasma monitors. NEC-Mitsubishi’s LCD monitor had quite a few interlaced artifacts, as did the Philips and Hitachi entries. I’d put the Vizio P4 right in the middle of that group. All of the review units are able to show a wide range of video and HD signal formats, but their pixel resolution varies considerably. You’d expect the higher-resolution panels from Philips, Hitachi, and NEC-Mitsubishi to look the best in this regard as they have higher pixel density – and you’d be just a little bit right. HDTV showed well on all screens, with a slight edge to the Panasonic, NEC, and Hitachi displays for neutral gray, good contrast, and image crispness. 480i and 480p DVD sources looked great on the Panasonic, NEC, and Hitachi monitors, although 480i/p images appeared just a tad soft on the Hitachi due to non-linear pixel scaling. (This is a problem also observed on the Philips 32FD9954.) It’s something you have to live with when using an AliS plasma monitor – video looks pretty good, but it’s just a tad softer than you would like. Of course, a Wide VGA panel is almost a perfect match to 480p sources and no vertical pixel scaling is required. RGB signals appeared uniformly crisp on the NEC plasma, Hitachi, NEC-Mitsubishi LCD, and Panasonic monitors, and just a tad softer on the Philips. The Vizio, of course, couldn’t size RGB images correctly that exceeded 640x480 resolution, so I saw either a section of the input signal, or the native 4x3 image stretched to 16x9. My overall favorite for image quality was impossible to choose, but three monitors in this review really stood out for different reasons. Panasonic’s TH-42PWD6 had the lowest black levels and most CRT-like picture, plus the best grayscale tracking. But NEC’s PS42VP4 and Hitachi’s CMP4201 also showed well with a bit more ‘punch’. I attribute this to their higher brightness readings and excellent contrast scores. CONCLUSIONS Scores
No doubt about it, plasma technology continues to improve as prices drop. The three 42” SDTV plasma monitors from Hitachi, NEC, and Panasonic can do almost everything well in a mixed-signal environment, and are well suited to digital signage. For many applications, Wide VGA resolution is more than enough for displaying still images, video, and larger type fonts. The Philips monitor is really intended for use as a plasma TV in the home, and it works very well in that capacity with the accessory FTR9964 AV control center and TV tuner. As a general-purpose multimedia monitor, it could use a few more controls and tweaks to tune up the image. V Inc.’s Vizio P4 is an interesting product that could also use a few more tweaks from the factory, including support for native RGB display modes and better grayscale tracking. But the price is very attractive – you get 4” more diagonal picture area for $1200 less than many well-known 42” SDTV monitors, and that’s a great deal. And there’s a built-in NTSC tuner to boot! NEC’s 40” LCD monitor showed a lot of promise, but did suffer somewhat from motion smear with fast images and higher black levels. As an RGB display, it worked exceedingly well. As a video display, it needs a bit of polish. But I see a quantum improvement every year in LCD picture quality, and next year – who knows? Maybe LCD technology will really give the plasma boys a run for their money! Copyright ©2003 Peter H. Putman / Primedia Business
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