Buying Guide: HDTVs Up Close
The HDTV plunge—everyone and their mother has either taken it already or is seriously tempted to do so. A brand new high-def set, however, is no small purchase. Which TV is right for you? A bright LCD set? A plasma with lusciously rich black levels? A supersize rear-projection model? Before you part ways with a serious wad of your hard-earned cash, you’d better be sure you have all the facts. In the pages that follow, we give you the info you need to swiftly settle on an HDTV that’s right for you.
Plasma TV sets generate the incredibly sharp resolutions necessary for high-def imagery by squeezing thousands of tiny gas-filled cells between two glass plates. These cells act like miniature neon lights and are activated and controlled via electricity. A decade has passed since the first plasma TVs arrived in stores, and odds are not many of those original sets remain in use today. The reason: Early plasmas were especially susceptible to the uneven wearing of the phosphors (usually a mix of neon and xeon gas) used to generate the light that creates the picture. The sad result is that these affected panels exhibited permanent image retention, otherwise known as the dreaded plasma “burn-in.” By contrast, today’s plasma televisions, such as the Samsung HP-S4273 and the Vizio VP42 HDTV, use far hardier phosphor formulas that better resist aging. These sets also incorporate a variety of electronic protection schemes that all but ensure that burn-in is a thing of the past.
A misconception about plasma TVs is that they can leak gas over time. Sorry, no: Plasma televisions do not “leak” gas or require periodic “recharging.” Nor do plasma televisions require special service or maintenance, beyond the occasional housekeeping you’d expect to perform with any other flat-panel television, such as basic recalibration. Some new plasma televisions feature screens rated for 100,000 hours of use until they reach half-brightness (LCDs are rated until backlight failure). A plasma television purchased today could conceivably operate continuously for more than 11 years before it reached the end of its life. That’s certainly something the plasma manufacturers couldn’t guarantee a decade ago.
Pioneer PRO-940HD This year witnessed the introduction of 42-inch and larger plasma televisions that offer native 1080p resolution, matching the maximum resolution of their LCD counterparts. Plasma sets, however, still can’t match the absolute screen brightness of an LCD, and most LCDs are better at minimizing ambient light reflecting off the screen surface. Also, LCDs are better suited for viewing at high altitudes, because plasmas make more electromechanical noise as altitude increases.
Those considerations aside, plasma televisions have a big ace up their sleeve in that they offer a significantly clearer and more detailed picture than LCDs when displaying moving imagery. That clarity also makes viewing video on a plasma television a less eye-fatiguing experience than watching the same content on an LCD. This is an especially important consideration for those marathon action-movie sessions. Moreover, in light-controlled environments screen brightness takes a distant backseat to other critical picture characteristics, such as black level, color quality, and effective video processing. Plasma televisions that are capable of operating at a 72-Hz refresh rate, such as the Pioneer PRO-940HD and the Pioneer PDP-5060HD, are also ideal for displaying 24-fps material (most DVD, Blu-ray, and HD DVD discs), since each frame is displayed three times (3 ≈ 24 Hz = 72 Hz); by contrast, when such content is converted for a traditional 60-Hz (that is, 60-fps) display, it appears in an uneven 3:2 frame cadence. These characteristics lead many to describe the plasma television as the movie lover’s HDTV.
LCDs: Bright and Sharp
LCD (liquid crystal display) HDTVs are the best-selling flat-panel display type available today. In fact, LCDs recently unseated the venerable cathode-ray tube (CRT) to become the best-selling display technology of any kind worldwide. LCD sets owe their strong appeal to several factors. First, LCDs produce a bright picture with a (usually) matte screen surface that minimizes the glare and reflections that can interfere with the viewing experience. When properly configured, LCDs are also the most energy-efficient display technology around. Finally, for widescreen sizes under 42 inches, the best LCDs offer unmatched sharpness of resolution—key for HD content.
Another benefit LCD manufacturers claim for their products is that they provide nearly 180-degree viewing angles. That’s true—sort of. In most cases, a picture is visible at these extreme angles. What’s seldom mentioned, however, is the apparent loss of color saturation that occurs in LCDs as viewing angles increase. This color-saturation loss tends to be initially perceptible at 20 to 30 degrees off head-on viewing. The 1080p Westinghouse TX-47F430S is one noteworthy exception, showing minimal color-saturation loss even at extreme angles. Instead, however, a purplish screen glare affects a growing portion of this TV’s image as the viewing angle increases.
Sharp AQUOS LC-52D92U Color accuracy, too, has proven troublesome for LCD technology. Greens that are too blue and colors that shift with changes in luminance are two of the issues I encounter most frequently with this type of television.
The dirt-cheap 46-inch WinBook 46D1 surprised me with its natural-looking out-of-the-box color quality. Moreover, its color tracking over dark-to-light intensities, while not perfect, was admirably linear and bested that of some more expensive models I’ve seen. Additionally, the 46D1 is the brightest LCD TV I’ve measured to date, making it suitable for brightly lit rooms. The Toshiba 37HL67 REGZA HDTV also offers good color quality without a lot of tweaking, and its generous three HDMI ports leave room for future expansion. Unfortunately, the 37HL67’s video processor isn’t as good with standard-definition (SD) video as with HD sources, so it’s best paired with set-top boxes that provide an HD signal—upconverted or native.
The ViewSonic N3751w is an example of an LCD that offers superior image contrast and a trio of HDMI ports, but it had problems processing interlaced video (SD or HD). If you’re willing to do (or pay someone else to do) a little work, the NEC Multeos M46-AVT includes precise color controls that professional calibrators can use to dial in the image quality to near-reference levels. It was also the first HDTV I’ve tested that properly deinterlaced 1080i video sourced from 24-fps material, preserving image quality and minimizing distracting artifacts.
In general, so-called 120-Hz LCDs are designed to produce clearer imagery than the traditional 60-Hz models, and I find that they succeed in doing so. The Sharp Aquos LC-52D92U, for example, offers a 52-inch screen, 1080p resolution, and 120-Hz conversion technology that seeks to minimize image smearing and other motion-related issues. Still, the Aquos occasionally introduced image corruption when displaying video containing fast motion. The complex electronics incorporated into modern HDTVs can pose unique problems as well. The Samsung LN-T5265F shipped with firmware that sacrificed about half the resolution of 1080i video—which is what you’ll commonly get with HD satellite and cable sources. This, therefore, is an unacceptable fault. While the image quality and performance of LCD flat-panel televisions has improved dramatically in the last few years, I’ve yet to see an LCD that can match the clarity of most HD plasma displays when displaying video that contains scenes with significant amounts of action.
A question about the future of LCD TVs concerns what light source they will use. LCDs use an array of lamps mounted behind the screen surface to produce the light we see, and the quality of an LCD’s backlight system directly corresponds to its ability to reproduce accurate color. A couple of years ago, a good LCD reproduced about 75 percent of the colors described in the HD spec. With new and improved fluorescent tube designs, some of today’s LCDs are boasting HD color coverage scores that exceed the spec by 90 percent.
For full HD color and beyond, LEDs (light-emitting diodes) have begun to replace fluorescent tubes in some premium LCD designs. The environmentally conscious should also note that the switch to LEDs as a backlight source eliminates the need for the bit of mercury present in fluorescent backlight tubes. Another benefit of LED lighting systems: They stabilize faster than fluorescent tubes, further speeding up a television’s startup time. Because LEDs can be precisely controlled (in terms of beam pattern, luminance, and color qualities), display manufacturers are also looking to use them to overcome classic LCD shortcomings, such as poor black and motion-performance problems. The downside of today’s LED-backlit LCDs, though, is cost—Samsung and Sony’s 70-inch models’ list prices top $30,000 each, for example. Smaller PC displays that offer LED backlighting typically cost five times as much as a similar model backlit with fluorescent tubes. LEDs and LCDs do play well together, but it will be a couple of years before this technology becomes affordable.
Rear-Projection Sets: More for the Money
Perhaps the most exciting thing about rear-projection televisions (RPTVs) is that they provide big-screen HDTV enjoyment at a fraction of the price of similar-size flat-panel displays. Unlike those of the last century, today’s RPTVs offer brighter imagery, improved longevity, slimmed-down cabinet designs, and ever-thinner bezels. And when viewing a modern RPTV only from the front, many people assume that it is a flat-panel TV.
All modern RPTVs have one of three competing microdisplay technologies at their hearts: DLP (Digital Light Processing, proprietary to Texas Instruments), liquid crystal on silicon (LCoS), and LCD. RPTVs that use DLP employ millions of hinge-mounted tiny (we’re talking micrometers here) mirrors, each of which reflects two pixels onto the screen. Some, such as the 65-inch Mitsubishi WD-65833 and the 56-inch Samsung HL-S5679W, provide 1080p resolution and a useful selection of A/V inputs, including multiple HDMI and component-video ports.
Samsung LN-T5265F Sony’s version of LCoS tech is dubbed SXRD, and the new Sony KDS-55A2020 SXRD uses a trio of these tiny panels to process the primary colors independently at 1080p resolution. These so-called three-chip projection systems typically offer motion performance superior to that of the single-chip light engine used in DLP RPTVs. My lab testing showed the KDS-55A2020 did quite well at preserving image detail when displaying video containing lots of motion. A TV screen that offers superior motion performance is less tiring to watch over extended periods of time. Properly configured, most modern RPTVs can deliver near-reference-level image quality in terms of color accuracy, contrast, and detail. All RPTVs, however, exhibit specific picture quirks that may make them less suitable for some room lighting and viewing situations. The viewing “sweet spot” for RPTVs is relatively narrow—particularly for vertical viewing angles. Ideally, you get the best viewing experience with RPTVs when you’re watching the screen from the center, at eye level. Most RPTVs exhibit a noticeable loss of luminance and image detail when viewed from as little as 25 degrees off front and center. Also, RPTVs direct most of the light emitted from the lamp module toward the center of the screen, resulting in the outer edges and corners of the picture measuring only about a third as bright. Interestingly, different RPTV screen sizes within a particular manufacturer’s series use the same lamp and light engine; thus the largest models often appear (and measure) significantly dimmer than smaller versions. Finally, RPTVs exhibit about 5.5 percent picture overscan, compared with the latest flat-panels, which keep every pixel of an HD video signal on the screen. An overscanned picture such as this results in a softer, less-detailed image.
Some of the latest RPTVs, including the Mitsubishi WD-65833, offer 120-Hz display technology that, like its flat-panel LCD counterparts, attempts to create a clearer-looking picture when displaying fast-moving imagery. The latest iteration of this so-called 120-Hz display technology works by compacting each frame from the original 60-Hz (60 frames per second) signal down to 1/120 of a second and then inserting an interpolated frame 60 fps. Although not foolproof, this method usually provides some improvement in apparent motion resolution. Another capability supported by the Mitsubishi WD-65833’s 120-Hz display technology is the company’s self-described “FX Gaming” option, which syncs with a pair of connected liquid-crystal shutter glasses to create a convincing 3D effect. The benefit of a 120-Hz display in this situation is that each eye (behind a liquid crystal shutter) receives 60 fps, thereby minimizing flicker and other potentially nausea-inducing artifacts—when compared with similar 3D displays that operate at slower refresh rates.
HDTV Minimum Viewing Distance
For viewing high-definition video on an HDTV, the optimal seating position places you close enough to provide an immersive experience but not so close as to cause you to strain to see the whole picture.
Related Stories
If you enjoyed this post, please consider to leave a comment or subscribe to the feed and get future articles delivered to your feed reader.
Comments
No comments yet.
Leave a comment