Panasonic TH-50PHD7UY Display

A Business-Class Plasma that Delivers Cinema-Quality Video

By Kevin Kilbride

March 1, 2005    Source: Studio Monthly

Panasonic claims a 3000:1 contrast ratio and 11-bit dynamic range for its new 50-inch color gas plasma display, the TH-50PHD7UY. Naturally, I wasted no time putting this claim to the test. After unpacking the double-boxed wide-screen behemoth, I lunged at it with DVDs in-hand, eager to bear witness to the fruit of its efforts to combine studio-quality gray scale and theater-grade contrast in a relatively inexpensive large-format, direct-view display device.

Trusting the nominal factory settings to be adequate for a first peek, I shuttled through a dozen or so scenes from my standard set of reviewing videos. Almost at once, a sinking feeling began to capsize my glee. The contrast was certainly there but the image appeared almost unnatural for it, and the highlights were slightly blown out. I swallowed my heart and muttered a mild curse to the deity of false hope, suspecting I might have been had by marketing hype. Fortunately, the story was far from over.

I settled down to the comparatively mundane task of making a clinical evaluation of the 50PHD. I read the manual. Examined the hardware. Scanned through the on-screen controls. Stop. What was that I just saw? Is this thing a chameleon or did someone do inexcusably immoral things to my tea this morning?

I quickly ruled out hallucination. Unlike most devices sold under the business-class banner, the 50PHD is just profoundly sensitive to parameter adjustment. If you intend to watch video on this machine, you absolutely must calibrate it first, although the "cinema" preset mode is at least close enough to optimal to do in a pinch. In the space of a few minutes, with a bit of relatively minor tweaking, I managed to completely remake the image quality of the display—so dramatically, in fact, that it didn’t even seem like the same device.

Calibrated Visions

Where the old display exhibited a very steep contrast curve that generated unpleasantly overstated flesh tones, the new display rendered humans in delicious pastels. The obnoxious edge detail of the old display, which had served primarily to highlight Gibbs artifacts (a.k.a. "mosquito noise") in marginally encoded DVDs, was nowhere to be found in the new display. The 50PHD had transformed itself from feral wildcat to purring pussycat.

If you think you can get away with just plugging in a source and pressing the "play" button, you are courting disappointment. At the very least, select from a preset mode appropriate for the content you’ll be showing, keeping in mind that the "standard" and "dynamic" settings of the 50PHD are not at all conservative. Many display devices intended for presentation are relatively insensitive to adjustment and factory configured to be reasonably neutral out-of-the-box. This Panasonic plasma is an exception to this rule.

Then again, there are times when radical contrast and edge detail might be genuinely helpful. If, for example, you need to display business graphics or promo content and want to plaster your audience’s eyeballs onto the back of their skulls, neutralizing their capacity for critical thought, no problem—just crank up the contrast and detail controls of the 50PHD (or, simply select its "standard" preset mode) and it will happily render a computer image so vivid that sustained viewing is actually uncomfortable. In fact, the Panasonic 50PHD can render a perfectly viewable image with such intensity that it begins to draw attention to temporal dithering algorithms needed to modulate pixel brightness, lending a perceptible "crawling flicker" to solid blocks of color. The effect remained noticeable, if looked for, to a distance of almost ten feet.

While extreme brightness may push certain types of images over the visual flicker threshold, it can help overcome the glare and reflections created by intense ambient light—something that is likely to be a factor in nearly all digital signage applications, and some presentation environments, as well. The coated glass face of the 50PHD is no more reflective than a CRT, but being flat, it produces perfectly undistorted virtual images of everything reflected. If the environment in front of the display is spot-lit or contains moving elements, the discernable reflections can prove rather distracting. Environmental reflections aren’t much of a problem with projection display systems, as incident ambient light is diffused at the screen and manages only to reduce contrast.

The default calibration of the 50PHD appears to reflect Panasonic’s hope that these devices will wind up being used more often for signage than to show movies. After all, Panasonic has a completely separate line of plasma displays specifically tailored for home theater use. By maximizing nominal brightness in their professional lineup, contrast can be maintained in spite of glare-induced degradation of the black level; also, the high-key content typical of signage applications should have no problem overcoming environmental reflections. Believe me, this machine is up to the task of competing with glare.

Better Cell Structure, But Too Much Noise

Panasonic claims the 50PHD has a 60,000-hour life; it also claims that the bounded-cell pixel structure used in its current panels not only enhances their peak brightness, but also makes them more resistant to image burn-in than prior color gas plasma devices. Naturally, I wasn’t in a position to test either assertion, but it is never a good idea to perpetually display static or sequentially-repeating high-contrast graphics on any phosphor-based display device.

One of the very minor gripes I have about the 50PHD is its lack of user-level parameter memories, making it impossible to effortlessly switch between custom calibrations. It’s obvious this panel was intended for use in fixed retail or lobby installations where a single source is likely to be permanently connected. It’s not really suitable for environments where impromptu optimizations must be made to match a wide variety of content types. Then again, calibration is seldom an issue if you’re displaying business or promotional graphics. If you do choose to calibrate the Panasonic panel, you won’t suffer for lack of control, as nearly every useful video parameter can be adjusted, including color temperature, white balance, black level and gamma exponent, along with the obligatory controls for brightness, contrast, tint and color saturation.

A variety of zoom modes can also be selected to maximize viewing area for different types of widescreen content. The zoom function even lets you set up video walls without an external signal processor. An external video splitter is still required, or a special pass-through input module can be used. The panels are capable of effortlessly creating 2 x 2, 3 x 3 and 4 x 4 configurations. Given the rather ample bezel margins around the display surface—ample, at least, in comparison to the almost non-existent bezels offered by certain rear-projection panels available today—the use of these devices for the creation of video walls is somewhat questionable, unless mounting space is at a premium or high-image contrast is required in environments saturated with ambient light.

The graphics card you use to drive the 50PHD must be selected with some care, as not all models support the panel’s native 1366 x 768 resolution. The nVIDIA Quadro FX 3000 (and presumably, all of nVIDIA’s similar GeForce cards) came close enough with a 1360 x 768 mode, but ATI’s Radeon 9200 could not produce any output—widescreen or otherwise—that was close enough to the required magic resolution to avoid creating aliasing artifacts in text and near-vertical lines. Hopefully, ATI will add support for this resolution in future versions of their Catalyst driver, if it hasn’t done so by the time you read this.

Unlike their consumer lineup of gas plasma displays, Panasonic’s business-class machines lack a TV tuner and internal speakers. They do, however, have internal audio amplifiers with terminals for connecting external speakers. With a decent set of near-field drivers, the audio quality of the built-in amplifier can be made quite respectable, albeit nothing that couldn’t be improved upon by outboard amplification. Bass, treble and balance controls are provided, in addition to a one-touch mute function on the remote.

Inputs Galore

The panels have one permanently-affixed DB-15 connector—switchable between RGB and color-difference input modes—and three slots for plug-in modules. A rich assortment of input modules are available for the HD-series of plasma displays, including composite, analog component, DVI, SDI, HD-SDI and wireless inputs, as well as twisted-pair remote feed adapters in both baseband and MPEG-2 varieties. Even a full-blown computer module is available, for use in creating stand-alone digital signage systems with Panasonic’s custom software. The unit I reviewed was fitted with two modules: one for broadcast-standard video in composite or S-video, and another for component YPrPb signals. Both modules employed BNC connectors, although versions with RCA connectors are available.

The panel’s computer-grade IEC-320 power connector featured a convenient locking attachment to prevent the power cord from being yanked out of the machine accidentally. All connectors and modules faced down, of course, permitting zero back-clearance mounting. The unit I was sent had cooling fans, but these are considered optional equipment. When I tested it, the panel’s considerable 500-watt power dissipation never became an issue. The fans never came on and the top of the unit remained cool-to-the-touch.

The unit did, however, make a surprising amount of noise—a crisp, high-voltage hum could be heard at a distance of several feet. I’m not sure if the cool and dry climatic conditions in which the unit was reviewed contributed to this unwanted emission, but its presence was rather surprising. It could actually be heard over quiet dialog passages when watching DVD content at a distance of about four feet, although it was not musical enough in character to be attention-robbing. By way of comparison, a 120 Hz powerline hum produced by very cold fluorescent light systems is considerably more annoying.

Overall, I came away feeling extremely good about the TH-50PHD7UY. It showed uncommon flexibility with respect to parametric calibration, and, once calibrated, yielded striking images. It appears to be part of a well-thought-out system with configurations that suit a wide range of applications and requirements. At the selling price this model is likely to hit with on the street, it can safely be called a bargain.

Smart Advice

There are times when radical contrast and edge detail might be genuinely helpful. If you need to display business graphics or promo content and want to plaster your audience’s eyeballs onto the back of their skulls, just crank up the contrast and detail controls of the 50PHD (or, ironically, simply select its "standard" preset mode) and it will happily render a computer image so vivid that sustained viewing is actually uncomfortable.