Build Quality and DesignApart from that small difference, the hardware is impressive, with a wide choice of inputs and outputs. That includes four HDMI ports, a PVR and Internet connectivity via your choice of an Ethernet port or, optionally, WiFi. There's also an IFC Pro 200 filter which reduces flicker and a media player.
That media player isn't up to what some of Panasonic's Korean rivals offer. It only supports a external devices formatted using FAT32, which limits it to files of no larger than 4 GB, but a good quality HD movie can easily occupy twice that much space. Worse still, very few file formats are supported.
There aren't many changes on the outside either, and the body isn't very stylish. A 7 cm thick bezel, wide frame around the screen and an ugly round stand don't make for a particularly aesthetically pleasing look. We can't wait for the next generation, which promises to be a little easier on the eyes.
Ghosting and Input LagThe panel used in the TX-L42D25 isn't one of the fastest, and is down at the bottom of our league with an average ghosting time of 18.5 ms (24 ms with a dark background and 13 ms with a light background). Input lag, though, isn't a problem: in Game mode, it's only two frames behind a CRT monitor, which is absolutely negligible. To put it another way, it won't hold gamers back, and everybody else can ignore this particular statistic.
Image QualityAs is all too often the case, the picture produced using the default settings is absolutely awful, with dreadful colour reproduction (the average deltaE is 9.7), a blue colour temperature and an unstable gamma curve. You might think that using dynamic backlighting would help compensate for the lower contrast usually offered by an IPS display, but our we only measured a ratio of 1000:1, which didn't leave us very optimistic for the rest of the test.
As we expected, even switching to True Cinema mode didn't do much to improve things. The contrast level falls back to 741:1 with blacks looking washed out at 127 cd/m². It's not all bad news, though, as IPS technology has other strengths, including wide viewing angles and brightness that's spread evenly across the whole display.
And it's not all bad with 'Real Cinema' mode either, as the picture does look more natural as a result. Colour reproduction is much better, and the deltaE falls to 2.8, an excellent result. This particular test measures the discrepancy between the colours provided on a source test card and those actually displayed on screen. We usually consider the discrepancy to be invisible to the naked eye when the score falls below 3.0.
Upscaling of SD content is a little too blurry, and we think Panasonic could have pushed the sharpness a little further to make the picture look a little more detailed. That's not necessary in HD, of course, and with Sharpness set to 0, the picture is more natural and closer to the original film. While we're on the subject, be careful not to turn the IFC filter up above 'medium', otherwise visual artefacts can creep in that adversely affect the picture.
Sound QualityMid-range and treble both come through loud and clear, but we can't say the same for the bass, which is totally inaudible. As is so often the case, we suggest you invest either in a sound bar or some Home Cinema speakers if you really want to enjoy tour next movie.
Energy ConsumptionOne of the main advantages of using LEDs to back light a TV is their low energy consumption. The TX-L42D25, which needs 91 W while switched on and under 0.1 W on standby, is one of the most efficient TVs we've seen.
- Low energy consumption: 91 W
- Accurate colour reproduction in True Cinema mode: average deltaE: 2.8
- Wide viewing angles, but not as good as with a plasma
- Built-in PVR
- Low contrast ratio (747:1)
- Glossy screen subject to reflections
- Mediocre remote with no backlit buttons
- Media player doesn't support many video formats
The TX-L42D25 really suffers from the poor contrast ratio provided by its IPS panel, which is a real disappointment.