Panasonic TC-55AS680U

DesignThe striking HDTV's top and side bezels are slightly curved, glossy black plastic. They would be plain on their own, if not for the addition of a metallic bezel on the bottom edge gives the screen a distinct look that doesn't distract. The HDTV sits on a U-shaped metal base that holds it securely with no wobble, but doesn't let it pivot left or right. A recessed space on the right side of the back of the screen holds Power, OK/Menu, Volume Up/Down, and Channel Up/Down buttons.

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The ports are lined along the left side of the back of the screen. An HDMI port and two USB ports face left for easy access, and two additional HDMI ports, an optical audio output, an antenna/cable connector, and an Ethernet port sit facing downward. A combination component/composite video input faces directly back.

Panasonic provides two different remotes with the 55AS680. There's a very conventional button-laden wand remote with large and friendly controls that aren't backlit, but are easy to find by feel, and there's a more compact touchpad remote. The smaller, flatter remote features a circular touchpad in the middle flanked by four small menu navigation and feature buttons. Power, Volume Up/Down, and Channel Up/Down buttons sit above the touchpad, while Home, Favorites, and Movie buttons sit below. A trigger on the underside of the remote provides an alternative to tapping the touchpad when selecting items on the menu. A microphone built into the touchpad remote offers voice search functionality when you press the microphone button next to the touchpad.

Whether you prefer the touchpad or the conventional remote is a matter of taste, but Panasonic's menu system seems to be built more around a direction pad than a touchpad. The cursor snaps to selections when swiping rather than moving like a mouse pointer, so the granular movement of the touchpad feels awkward. The circular shape of the touchpad offers one nice control feature over the button remote, though: You can scroll through long lists by moving your thumb in a circle along the edge of the touchpad.

My Home ScreenLike Panasonic's other connected HDTVs, the AS680's interface is built around the company's My Home Screen system. Users can customize their home screens in tile-based arrangements, with the main video input as the largest and most prominent tile surrounded by favorite apps, widgets, and shortcuts. It's a useful feature that lets different family members set their own preferred home screens and shortcuts, or for you to arrange multiple screens based on need.

All of the usual online services suspects are available out of the box, including Netflix, Hulu Plus, and Amazon Instant Video. The AS680U also features a Web browser, built-in voice and video memo features (the video feature requires an optional USB webcam among a list of supported models), screen mirroring over Miracast, and a media player for both locally connected and networked storage. My Stream takes your favorite online services and, if you set it up, cable or satellite provider and presents a tile-based view of recommendations for what to watch.

See How We Test HDTVs

PerformanceWe test HDTVs with a Klein K-10A colorimeter, SpectraCal's CalMAN 5 software, and DisplayMate test patterns. After a basic dark room calibration, we found the best setting for testing was Custom picture mode, Warm2 color temperature, Brightness +1, and Contrast 100. We normally set Backlight to maximum for testing, but the AS680 produced a noticeable high-pitched whine on that setting. Setting Backlight to 80 seemed to eliminate this problem, while offering a very bright 334.99 cd/m² peak brightness (with Backlight at 100, peak brightness increased to an eye-burning 436.48). Unfortunately, black level was a much less impressive 0.1 cd/m², which is disappointing when less pricey screens like the TCL 48FS4610R can reach 0.07 cd/m² and below. This resulted in a modest 3,350:1 contrast ratio. We could coax the black level down to 0.03 cd/m² in Cinema mode, but this slashed the peak brightness to 80.41 for an even lower contrast ratio of 2,680. For reference, the more expensive Sony KDL-60W850B only gets a third as bright as either screen, but it can reach a remarkable 0.005 cd/m² for an impressive 21,156:1 contrast ratio.

The chart above shows measured color levels as dots and ideal color levels as boxes. The AS680U's color accuracy was nearly spot-on, with close to ideal whites and slightly oversaturated, but not particularly skewed reds and blues. Greens leaned a little bit cool, but not significantly.

I watched The Amazing Spider-Man on the screen, and bright scenes look fairly inky when viewing in a dark room under the calibrated settings, thanks to the very bright highlights the panel is capable of displaying. Unfortunately, the dark-by-comparison blacks don't show much shadow detail in dark scenes; Fine textures and contours like shadow-obscured clothes and hair in the alley scenes effectively disappeared from the picture. Colors were generally accurate and flesh tones looked natural thanks to the strong reds, even if the overall picture occasionally leaned just a hair cooler than ideal. If you can get past the poor shadows, the 55AS680U offers a bright, vivid picture that doesn't go overboard into looking cartoonish.

The Big Lebowski, a film with awkward colors and fewer dark scenes, looked excellent on the 55AS680U. The harsh fluorescent light of the bowling alley didn't harm the varied skin tones of the characters or make The Jesus' purple suit appear muted or skewed. The colors look vivid and accurate, but don't ever appear gaudy or overblown.

Gaming purists will be disappointed by the 55AS680U's input lag, which was a considerable 131.9 milliseconds in our testing. The 55AS680U does offer a Game mode, which chops that number in half to a still underwhelming 69.4 milliseconds. Most gamers won't notice much of a problem with Game mode enabled, but this is not a screen for competitive players who want to count frames and practice their fighting game strategies.

Under normal viewing conditions, the 55AS680U consumes 129 watts with our calibrated settings. This is a bit high, although not unreasonable for a 55-inch HDTV, especially one that can get this bright. Turning the Energy Saving profile on to "Saving" reduces that to 111 watts. The Standard picture mode is Energy Star compliant, and slashes power consumption down to a mere 66 watts, but noticeably darkens the picture in the process. It's still watchable in Standard mode, especially in dark rooms, but it is quite dim compared with our calibrated settings. For contrast, the 60-inch Sony KDL-60W850B consumes only 57 watts with little dimming or harm the picture.

Conclusion
Panasonic's TC-55AS680U is a solid HDTV on paper, and its colors are very well-balanced, but its price tag and poor contrast leave it behind more affordable connected options like the TCL 55FS4610R$629.99 at Dell. It's a good choice if you can find it at a discount, and you value the design and functional My Home Screen features, but its list price and picture quality don't match up.