Click the image at the right to see the picture settings used in the review and to read more about how this TV's picture controls worked during calibration.
Black level: The ST50 produced an extremely dark shade of black that competed well against the generally more expensive TVs in the lineup when I watched "Hugo." In dark scenes, such as Hugo's entrance into his train station hideaway (chapter 2, 9:53 and later), it delivered depth of black that looked nearly indistinguishable from the picture on the VT30 and the D7000, and darker than that of either the ST30 or the Sony NX720. Only the Kuro and the Sharp Elite showed a picture that seemed darker.
"Hugo" lacks letterbox bars, which make judging relative black levels easier, so I tried out "Tron" and saw much the same results -- if anything the ST50 improved. It outdid the black of the D7000 and even of the VT30, although again the two uberexpensive Elites won the day (handily). At times the Sony managed a deeper black than the ST50, for example, during the opening sequence with the grid lines, but only when the screen was almost completely black.
It's important to remember than the VT30, ST30, and D7000 TVs were aged, causing them to show different black levels than when they were new. Comparing initial black-level measurements, however, the ST50's stellar 0.005 Fl (see the Geek Box below) is still darker than even the VT30's initial measurement (0.0061). Of course I can't say how the ST50 will age, but if the 2011 Panasonics are any indication, it won't get much worse during the first year.
Aside from depth of black, the ST50 also improved upon on the gamma and shadow detail of the 2011 Panasonics, matching the Samsung and Elites in this crucial characteristic. In chapter 2 of "Hugo," for example, the brightness of the shadows and interplay of light and dark areas in the walls, gears, and ceiling struts looked natural and not too light, as with the other Panasonics, nor too dark, as with the Sony.
I kept an eye out for floating blacks, or noticeable fluctuations in black and very dark areas, but didn't see any during the segments I watched. I also checked out the scenes from "Tron" that caused such fluctuations last year on the GT30, but didn't see them on this set.
Color accuracy: In the past I've complained about Panasonic plasmas' tendency toward too-green skin tones, red push, or lack of saturation, but the ST50 had none of these issues. It delivered the most accurate color I've seen on any Panasonic after a user-menu-only calibration. It came close to the reference Samsung in this area, and outdid the others aside from the VT30 (which looked nearly the same) in various ways. Skin tones, such as the face of Hugo when he visits Georges' house (chapter 8, 56:56), looked natural and lifelike, without the too-blue tint of the Sony or the more washed-out look of the ST30. Compared with the D7000, the ST50 did appear a bit warmer and redder in some areas, but the difference was very subtle.
T Of course the ST50 looked more accurate than the Sharp Elite since (like the other sets) it didn't desaturate cyan. The new Panasonic also showed rich, balanced color in other areas, for example the flowers at Lisette's stand (1:06:31). I also appreciated that near-black areas remained true and not overly tinged with blue or green.
Video processing: Like its 2011 brothers, the TC-PST50 passed our 1080p/24 test on its 60Hz setting. It cadence was smooth and properly filmlike, indistinguishable from the look of the other sets in our lineup that handled 1080p/24 properly. As usual, I found the 48Hz mode flickered too much to be watchable.
On the other hand, I did notice some artifacts from 1080p/24 sources in 60Hz mode. On the Digital Video Essentials test Blu-ray I noticed shifting lines and minor instability in the downtown Philadelphia buildings during an upward-facing pan. I didn't see any similar issues during other program material, but assume they might crop up.
Panasonic's Motion Smoother delivers three options, Weak, Medium, and Strong, and as usual I found all three relatively distasteful and preferred to leave the setting off. When engaged, Motion Smoother caused an improvement in motion resolution in our test pattern (see the Geek Box), but it's not worth the smoothing in our book because any blur was impossible for us to discern with real program material.
The ST50 passed our 1080i deinterlacing test with 3:2 pull-down set to On, but not when I used the default Auto (and, despite what the menu explanation says, this setting does affect HDMI sources).
Bright lighting: The ST50 handled overhead lighting better than any plasma I've ever tested. Comparing it with last year's Panasonics, the filter over the screen is better in both important ways. Under the lights, dark areas looked a bit darker on the ST50 than on the 2011 Panasonics as well as the Samsung D7000 plasma. Reflections in the ST50's screen also appeared a bit dimmer than on the other Panasonic plasmas, although the Samsung D7000 showed the dimmest reflections of all. Both LCDs (Sony and Sharp) preserved black areas' darkness better than the ST50, but their reflections were significantly brighter and more distracting.
Panasonic's Louvre Filter acts like venetian blinds to reject light coming from above. Compared with last year's VT30, the ST50's filter did dim the image a bit more when seen from high off-angle vertically. In practice this difference is only visible from angles that are roughly equivalent to placing the TV on the floor. As usual for a plasma, horizontal off-angle viewing, which is far more important than vertical in typical living-room situations, looked essentially perfect -- in marked contrast to both LCDs, for example.
3D: Overall the ST50 didn't maintain as impressive an image with 3D sources, but it was still solid. I compared it in a lineup that also included the passive 3D Vizio M3D550SR, the 2012 Sony KDL-55HX750, and our current 3D reference TV, the Samsung UN55D8000.
The first chapter of "Hugo" (a movie I plan to use for all 3D testing this year since it has significant depth and lots of interesting camera movement, is live action as opposed to animation, and was shot completely in 3D) has some scenes where crosstalk was quite prominent on the ST50. The ghostly double-image was especially visible on as Hugo's hand as it reached for the mouse (5:01), the tuning pegs on the guitar (7:49) and the face of the dog as it watches the inspector slide by (9:24), for example. The VT30 looked nearly the same in comparison, but the PND7000, the Elite, the UND8000, the HX750, and the Vizio all showed less crosstalk than either Panasonic.
Updated June 5, 2012: The above comments were made with the TV on its default 60Hz setting. Since this review was published I've had the chance to test the ST50's 3D picture quality in a different lineup using the 48Hz setting instead. It worked very well to reduce crosstalk, and elevated the ST50 to the same level in this area as a competing Samsung plasma. For more details and comparisons, check out the 3D section of the Panasonic TC-PVT50 series review.
In the default Cinema, Movie, or THX settings (I don't calibrate for 3D) the ST50's 3D black levels looked deep enough, with good shadow detail, but didn't look appreciably deeper than those of any of the others, aside from the Sony HX750 and the Vizio. Its color also seemed a bit too blue, especially in dark areas, although it wasn't egregious. Of course any of these differences could change with a calibration in 3D. I did not test 2D-to-3D conversion.
Panasonic's new 2012 glasses are lighter and fit better than either of their predecessors. The Bluetooth connection also seemed to maintain sync better than the old Infrared method.
Power consumption: [Note that this test and all of the chart numbers below only apply to the 55-inch TC-P55ST50, not any of the other sizes.] The 55ST50 uses significantly more juice than any similarly-sized LED or LCD-based TV, but it's a bit more efficient than the 55-inch VT30 from 2011. As usual for plasma, the default picture preset (Standard) is vanishingly dim with the room lighting sensor disabled; just 14 Fl compared with our dim-room target of 40 Fl. That explains the more than 100-watt difference between the two.
This year, due to the hard cap of 108 watts for any size of TV imposed by Energy Star's latest 5.3 specification, 55-inch and larger Panasonic plasmas fail to earn the blue sticker. The only Energy Star-qualified TV in this series is the 50-inch TC-P50ST50.
Editors' note: CNET has dropped TV power-consumption testing for 60-inch or smaller LCD and LED-based TVs because their power use, in terms of yearly cost, is negligible. We will continue to test the power use of larger LCD or LED models, as well as all plasma OLED models.
|Panasonic TC-P55ST50||Picture settings|
|Picture on (watts)||142.75||246.97||N/A|
|Picture on (watts/sq. inch)||0.11||0.19||N/A|
|Cost per year||$31.40||$54.24||N/A|
|Score (considering size)||Poor|
|Black luminance (0%)||0.005||Good|
|Near-black x/y (5%)||0.3306/0.3624||Average|
|Dark gray x/y (20%)||0.3137/0.3331||Average|
|Bright gray x/y (70%)||0.3134/0.328||Good|
|Before avg. color temp.||6796||Poor|
|After avg. color temp.||6395||Average|
|Red lum. error (de94_L)||0.315||Good|
|Green lum. error (de94_L)||2.5755||Average|
|Blue lum. error (de94_L)||0.191||Good|
|Cyan hue x/y||0.2216/0.3216||Good|
|Magenta hue x/y||0.3227/0.1542||Good|
|Yellow hue x/y||0.4259/0.5064||Good|
|1080p/24 Cadence (IAL)||Pass||Good|
|1080i Deinterlacing (film)||Pass||Good|
|Motion resolution (max)||1200||Good|
|Motion resolution (dejudder off)||900||Good|