Review: Panasonic Viera TX-L47DT50

Our score: 3/5
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May 18, 2012 2:51 PM
 
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Published: April 16, 2012 10:52 AM
By Pierre-Jean Alzieu / Pierre Anzil
Translated by: Catherine Barraclough
While Panasonic has long favoured plasma technology, the firm does make a selection of LCD TVs. In fact, the Japanese manufacturer is looking to boost its LCD range over the coming years. Its 2012 series is the firm's second to use IPS-Alpha LCD screen panels—technology developed in-house and used exclusively in Panasonic TVs.

Alongside the top-of-the-range WT50, Panasonic also sells the DT50, another LCD TV with active shutter 3D. It's equipped with all the latest must-have functions, including smart TV services (Viera connect), DLNA compatibility and 1600 Hz motion interpolation (for a native screen frequency of 200 Hz).

The DT50 is available in three different sizes: the 42" (107 cm) TX-L42DT50, the 47" (119 cm) TX-L47DT50 or the 55" (140 cm) TX-L55DT50.

Panasonic L47DT50 TV review - sub-pixels
Sub-pixels in the IPS-Alpha screen

Functions and Design

Thanks to Edge LED backlighting, the DT50 has a slim casing (2.7 cm) with a metal bezel and stand. It has an understated yet stylish design and an excellent-quality finish.

Panasonic L47DT50 TV review - panasonic logo

The only detail that some people in our office weren't too sure about was the plastic strip at the bottom of the screen bezel, whose only purpose seems to be making room for a slightly garish light-up Panasonic logo. While we can understand that a manufacturer wants its name to appear on its products, we would have preferred to see a logo subtly engraved in the casing. That, however, is a matter of taste.

Panasonic has equipped this TV with a new remote control. It's the same shape as Panasonic's former remote, but the layout of the buttons has changed. The volume and channel controls have, for example, been moved further up into the middle of the remote, above the numeric keypad. The remote is backlit too, which can be handy when you're watching a film with the lights off.

Once connected to the web via Ethernet or Wi-Fi (built-in), this TV offers access to Panasonic's Viera connect services. There are plenty of apps to choose from and they're all pretty good quality. You'll find the usual selection of popular apps, such as YouTube (with HD video functionality), Skype, Twitter, Facebook and Google Maps, as well as more unusual content such as Gameloft games—although you will have to pay up to £5 for games like Asphalt 5!

The new web browser is now compatible with HTML 5, but this update unfortunately hadn't been released at the time we reviewed the DT50 so we weren't able to test it.

Panasonic L47DT50 TV review - glossy screen
Screen: prone to reflections
 
Panasonic L47DT50 TV review - metal screen bezel Metal screen bezel
 

Panasonic L47DT50 TV review - viera cast
Viera Cast menu
Panasonic L47DT50 TV review - remote control
Remote control


It's good to see that file support has been boosted in the built-in media player. Although it's still not quite up there with the best, Panasonic has seriously closed the gap with Korean manufacturers on that front. NTFS (Windows format) peripherals are now supported, bringing compatibility with files over 4 GB in size—which isn't the case with FAT 32. Most video container formats are supported, including AVI, DivX, MP4, MKV, MOV, MTS and M2TS. Only ISO files (disc cover images) and DVD or Blu-ray disc menus are still problematic.

Responsiveness and Ghosting Time

Responsiveness
Panasonic L47DT50 TV review - ghosting
 Light
Background
Black
Background
Average
This graph shows the ghosting time, measured in ms, which measures the time it takes this TV takes to entirely remove the previous frame. The shorter the time, the more fluid moving images will appear.

Panasonic's 2012 IPS-Alpha screen does an excellent job compared with last year's model, as the ghosting time has been halved from 13 ms to 7.5 ms. This puts the DT50 up there with he best TVs we've tested yet, including Philips LCD TVs using Sharp screens and plasma-screen TVs (which generally score between 7 and 8 ms).

2D Picture Quality

While screen responsiveness has improved, the out-of-the-box screen settings certainly haven't. The default settings are clearly designed to look pleasing and eye-catching to novice users but they won't wash with specialist or advanced users. Colours are therefore very vivid and an average Delta E of 6.7 means that colour fidelity is off the mark (a reading of three or under gives accurate colours). Brightness levels (gamma) are poorly balanced, washing light greys out to white, and the grey scale is too cold (too blue). You can make things better by switching to True Cinema mode although the result still isn't perfect. Colours, in particular, still aren't reproduced accurately, with an average Delta E measured at 5.2 (don't forget, the lower the better) while most TVs manage to push down under 3.

UPDATE 2/10/2012: following a firmware update, colour fidelity in the DT50 has greatly improved. The average Delta E has been cut from de 5.2 to 3.1. That's perfect!

Panasonic L47DT50 TV review - contrast
In True Cinema mode we measured contrast at 850:1

The contrast ratio hasn't evolved since 2011. We measured 830:1 for the DT50, while we were expecting to see at least 2000:1. In fact, the best TVs these days can reach 5000:1. Blacks therefore do tend to look grey, which is a real disappointment! To make up for the lack of contrast, you're better off watching this TV in rooms with decent levels of ambient light, as it'll trick your eyes into seeing a darker black. This, however, remains a trick rather than a genuine solution.

In the past, IPS screens have been known for delivering wider viewing angles than other types of LCD screen technology. That's certainly true in this Panasonic panel, as with an average variation in brightness of 28% around the edges of the screen, the IPS-Alpha panel in this TX-L47DT50 TV gets a score of 3/5 for viewing angles, when most of the TVs we've reviewed scored between 0.8/5 and 2/5 (that's a 55% to 35% variation in brightness).

For watching films, like in most TVs, the SD upscaling (DVD) isn't amazing in this model. You're therefore better off using a latest-generation games console (PlayStation 3 or Xbox 360) as these use a more advanced graphics system to ensure better results. HD images look perfect, however. Users looking for super-smooth pictures should set Intelligent Frame Creation from 'maximum' to 'minimum'. The motion interpolation function will then eliminate judder and glitches while minimising the 'video' or 'camcorder' effect.

Clouding

We didn't notice any problems with clouding in this TV. In other words, there was no light leaking through where it shouldn't be!

3D Picture Quality

The improved screen responsiveness allows Panasonic to deliver almost flawless 3D picture quality in scenes that aren't too contrasted. That's real progress since 2011. White on black still causes a few problems with images for the left and right eyes doubling up (crosstalk), but it's pretty rare to see a white object on a black background in most 3D content. With quality like this, the DT50 isn't far behind Panasonic's plasma TVs.

Panasonic's active shutter 3D glasses are very good quality. Although they're quite expensive (around £50), they're comfortable to wear and can feasibly be used over the top of regular glasses

Below—the result as seen through 3D glasses (Top: Panasonic TX-L47DT50 / Bottom: Philips 40PFL8606H):

Panasonic L47DT50 TV review - 3d picture quality
Panasonic L47DT50 TV review - crosstalk

 With a perfect result, we shouldn't see any trace of the 'R' frame on the left, and, vice versa, none of the 'L' frame on the right.  For the time being, only plasmas from Samsung and Panasonic get this right.

As is often the case, the 2D-to-3D conversion function in this TV doesn't give great results. In fact, it only brings a very slight impression of depth to the picture. It's the kind of thing that's fun for about five minutes, but it's no replacement for genuine 3D content.

Audio Quality

As outlined in this TV's spec sheet, the Panasonic DT50 has two speakers, as well as a woofer to take care of the bass (frequencies below 50 Hz). However, the two speakers are so small that the woofer ends up doing pretty much all of the work, which, in the end, makes the audio output sound more like mono than stereo.

That's a shame, as the central speaker (the woofer) gives good-quality audio. A second speaker like this could have helped the DT50 get a fourth star in this section.

Power Use

Like many TVs on the market right now, the DT50 is an energy efficient device. We measured standby power use at 1 watt. When up and running, we measured 75 watts for this 47-inch TV (which makes 123 W/m²). 
3/5 Panasonic Viera TX-L47DT50 DigitalVersus 2012-04-16 11:52:00

Pros

  • Good 3D image quality / Crosstalk kept in check
  • Firmware update brings accurate colours: average Delta E 3.1
  • Low power use: 75 watts
  • Effective motion interpolation
  • Media player supports most file formats
  • Backlit remote

Cons

  • Low contrast: 830:1

Conclusion

Panasonic has made huge progress with its IPS-Alpha LCD screen technology. The DT50 is as responsive as a plasma TV—so much so that 3D image quality is excellent. However, the contrast is too low (830:1). The DT50 therefore misses out on a fourth star.

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