A Business-Class Plasma that Delivers Cinema-Quality Video

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.