The Panasonic TH-50PZ800U is one of the first HDTVs to earn THX certification. But you might ask, “Isn’t THX mainly into audio?” I can see where you’re coming from, but THX isn’t exactly new to the home video business. It has certified video software for years and has begun to do the same for projectors and flat-panel displays.

To that end, THX has developed performance parameter tests that cover such characteristics as video processing, contrast, color accuracy, and resolution. Panasonic is one of the first manufacturers to bring a THX-certified set to market.

But there’s more to the TH-50PZ800U than just the THX seal of approval—and perhaps a bit less as well. The set omits a few of the goodies available in other Pan-asonic lines, such as panel brightness, gamma selection, user menu white-balance adjustments, the Studio Ref mode option (replaced by a THX mode), and VIERA Cast (which directly connects you to a limited number of Panasonic-selected Internet sites).

Looking Around
The Panasonic reflects the times with its four HDMI 1.3 and two component video connections. There is no USB port, no Ethernet port, and no accessible RS-232 jack. However, there is an SD card slot for viewing your JPEG photos and standard-definition videos. A few of the connections are on the set’s easily accessible front panel behind a drop-down door. The latter provides a shared composite and S-video input with L/R audio, one of the HDMI jacks, and the SD card slot.

The set has five adjustable picture modes: Vivid, Standard, THX, Custom (Photo), and Game. We performed all of the testing here in the THX mode. Unlike the only other THX-certified set we have tested so far (from LG), most of the picture controls in the Panasonic’s THX setting can be changed by the user. I had to crank the Picture (contrast) control up considerably past the THX out-of-box setting to match the peak white window brightness available from the other sets. This did significantly limit how far the set would go above white, but it still did go above white. No one commented on any negative effects from the high Picture setting. But the Panasonic was the only set of the group that would not reproduce information below black.

The set offers limited user control with color temperature and color gamut. Fortunately, the color gamut wasn’t too far off—although it’s a bit less accurate than the other sets. And the color tracking was respectable. The latter could be somewhat improved via the service menu, and as with all the sets here, we conducted the panel tests only after a full calibration (see “HT Labs Measures”).

The Panasonic will accept a 1080p/24 input and display it at 48 or 60 frames per second (for the latter, it adds 3:2 pulldown). As noted in the introduction, I chose the 60-fps setting for all the testing and viewing reported. In the 24-fps setting, there was noticeable flicker in bright images with large expanses of white or color (such as blue sky). This was particularly annoying when we viewed the Panasonic next to the other sets. (The Sony and Samsung refresh 24-fps sources at 120 Hz, the Pioneer at 72 Hz.)

The Panasonic’s Color Management control is a simple on/off affair that I left off. The Contrast Automatic Tracking System (C.A.T.S.) dynamically adjusts brightness and contrast in response to a room light sensor. I left this off as well and did the same for most of the other special adjustments. But that didn’t involve many choices.

Overall, the Panasonic offered the fewest user picture adjustments of all the sets reviewed. Depending on how much you like to fiddle with controls, this can be either a blessing or a disappointment.

The Panasonic’s 480i-to-1080p video processing turned in a good score overall, with correct recognition of 3:2 pulldown. It did get a poor score on our waving-flag test, with noticeable jaggies. However, while it had little trouble with any of our other standard test material, it was fair at best on our 1080i-to-1080p tests. While it turned in good scores on much of the material, it failed to recognize 3:2 pulldown and displayed moiré or flicker on the Vatican wall and steps on chapters 7 and 8 of Mission: Impossible III.

The Judges Speak
The Panasonic earned mixed scores on black level and shadow detail. The blacks were clearly the lightest of the group on a full black screen or on a very dark scene. They were more medium gray than black—when the sets were all viewed directly from screen center, that is. The Panasonic and Pioneer plasmas’ images held up to as far off axis as anyone could sit and still see the picture, while the Sony and Samsung LCDs lightened noticeably at even a few degrees off center.

But a few scenes clearly showed the Panasonic’s black level limits: the opening scenes from Master and Commander: The Far Side of the World, the near-black screen in the opening star field on Stargate: Continuum, and the shipping-crate scene from chapter 6 of Madagascar (in which the characters are shown brightly lit in shipping crates surrounded by total darkness). Its limits also showed with black bars on letterboxed material.

But the perceived blacks were richer when the scene brightened a bit from very dark to largely black with significant bright highlights. The somewhat higher blacks than the other sets also revealed shadow details that impressed some of the judges enough to produce higher grades than might have been expected from the absolute black level. These details were sometimes obscured in sets with deeper, richer blacks. There were more than a few comments about the Panasonic’s respectable shadow detail. The panelists made comments such as, “Held up pretty good, despite elevated black level,” and, “Could see into shadows, sometimes revealing details not seen on other sets.” But the latter commentator tempered this by adding that these details were “sometimes muddy, not crisp.”

One panelist thought the Panasonic’s colors really popped on some program material, particularly the animated Madagascar, but she found that it got tiring on some other material. She thought skintones, white clouds, and a few other details were a bit too rosy-looking. This is very likely a reflection on a narrow but sharp uptick in the reds visible in the mid-brightness region on our measurements (uncorrectable in calibration without making the rest of the range too blue-green, an error that would be far more visible). There were some criticisms of mild banding on blue skies and reds that looked a bit too light. But the criticisms were relatively mild, and one judge remarked that he “never felt that anything looked unnatural.”

A few panelists remarked about the few video-processing anomalies in the Panasonic, particularly moiré in chapter 7 of Mission: Impossible III (on the bricks in the Vatican wall) and a bit of shimmering (but no moiré) in the staircase at the beginning of chapter 8. All of the other sets performed cleanly on this material.

Otherwise, the set’s detail was very good. Measurements showed that the luma (black and white) response on a 37.1-megahertz (HD maximum) frequency burst appeared stronger than the burst at 18.5 MHz. This may have resulted in a slight exaggeration of real details and even anomalies in the source. Reviewers commented that the Panasonic looked a tad noisier (or perhaps it just made film grain appear more pronounced). There was one comment on an oversharpened look in a standard-definition test (upconverted to 1080p in the set). However, one written comment called the Panasonic’s overall detail “fantastic,” although the same judge found its handling of 1080i material “problematic” (likely referring to the M:I:III clip mentioned above). While he did not criticize the Panasonic’s motion performance specifically, another panelist thought the Pioneer’s detail held up better on moving objects.

Conclusions
The Panasonic’s video processing was a weak point. It was at its worst on the most difficult 1080i material (M:I:III in our tests), where it didn’t respond properly to 3:2 pulldown. The set’s color was a little warm for some of the judges, but it drew satisfactory scores on both color and detail. None of the judges commented about the off-axis performance or found this characteristic (a strength of plasmas) of concern.

While two of the three other sets in the group outperformed it overall, the Panasonic held its own, particularly at its price. It received the highest score for value, which strongly suggests that the panel, overall, liked what it saw.