Panasonic TX-L42ET50B 3D LED LCD TV Review

Black Level

Let’s not sugar-coat it: black-level depth is not one of the strong points of IPS LCD panels, such as the one used in this HDTV. Vertical Alignment (VA) panels do much better in this category, but, as Panasonic is quick to point out, they suffer from worse viewing angle limitations than IPS.

The black level the Panasonic TX-L42ET50B achieves depends on how the [Contrast] control – which controls the intensity of the LED lighting – is set. We calibrated it so that peak white sat at 119 cd/m2, meaning that we achieved blacks of 0.16 cd/m2 in the centre of the screen (the edges were slightly brighter, as is common for LED-sidelit LCD TVs). Under its default out-of-the-box factory settings, the TX-L42ET50 puts out a very bright 194 cd/m2 peak white, and a brighter 0.23 cd/m2 black.

To put these black level readings into perspective, the mid-range ST50 Plasma display, which Panasonic delivered to us alongside the ET50, managed an extraordinary 0.009 cd/m2, which is nearly 20 times better. (Plasmas also deliver a colourless black, whereas the TX-L42ET50’s blacks were actually a very dark purple). Samsung’s best VA LCD panels manage a very respectable 0.03 cd/m2 – provided you’re sitting face-on with the screen; like any LCD, the blacks turn greyer when the panel is viewed from the sides.

Remember that these measurements were taken with the True Cinema mode, which uses static backlighting. The other modes feature dynamic backlighting, and under these, the TX-L42ET50 managed 0.04 cd/m2 – of course, that’s with a black screen, which isn’t much fun to watch! Dynamic backlighting is only good for black screens and other predominantly dark scenes, and will be of no use when black and white have to co-exist on the screen simultaneously. In any case, it’s not an option in the True Cinema mode.

Viewing Angle

There’s no question that the viewing angle performance of IPS LCD panels is superior to the more common VA types. Sitting to the side results in a picture that darkens slightly, but the darkening appears almost uniform, unlike VA panels which often emphasise brighter or darker parts of the picture differently, resulting in a less natural off-angle image. What’s more, the greyscale characteristics stayed the same, meaning that the picture didn’t pick up a pinkish tint when viewed from the sides, something we’ve seen on competing types. Colours also kept a good amount of their saturated look.

However, the viewing angle performance of the IPS panel in the TX-L42ET50B, while very good for an LCD-based display, is still far below that of a Plasma television. The single biggest remaining weakness is that in a dark room, blacks still turn grey when viewed off-axis. Dark scenes do not escape the viewing angle limitations.

Motion Resolution

The basic motion performance – that is, with any motion-enhancing systems disabled – turned out to be the usual baseline LCD result of 300 lines, which results in fairly blurred motion during high motion content (for example, televised sports).

To get access to the advertised 800hz Backlight Scanning, the [Intelligent Frame Creation] system must be turned on. We used it on the “Min” (lowest) setting, and saw an immediate increase in resolution, which was now at the full 1080 lines on the FPD Benchmark test disc. What’s more, selecting “Min” did not introduce the dreaded “soap opera effect” into films. We confirmed with our own motion interpolation detection pattern that the ET50 was performing motion processing on the image, but it was very mild, and didn’t impose itself on the image like the “Mid” and “Max” settings did. Unlike some implementations of backlight scanning, the picture did not darken.

In addition to their wider viewing angle, IPS LCD panels are known for producing better quality motion than their VA LCD counterparts. We found this to be true on the Panasonic TX-L42ET50, which produced essentially no smeared blacks – something that VA LCD panels can’t boast of.

As a result, we enjoyed motion performance that was very good by LCD standards, using the “Min” [Intelligent Frame Creation] setting to fight off LCD blur. Fast camera pans in video camera generated footage (such as you’ll find on most drama, news and factual shows) material still result in blurring, though, meaning that the Backlight Scanning technique doesn’t translate into Plasma levels of performance with all real-world material.

Screen Uniformity

Side-lit LED LCD HDTVs tend to perform very poorly with regard to screen uniformity. Because the displays are incredibly thin, with the LED light sources clustered to the sides of the screen, the panel is illuminated by scattering the light from these LEDs across the screen. It appears that this is very difficult to do with perfect accuracy, meaning that many of the LED-sidelit televisions we see have poor uniformity.

Panasonic’s have always done surprisingly well in this area, and indeed, while a full grey screen revealed that the uniformity wasn’t perfect, it was considerably better than many of the VA-based edge-lit LCDs we’ve seen, to the extent that with most real-life content we couldn’t actually pick out any uniformity problems. This is excellent performance for a edge LED LCD TV.

3D Material

Given that Panasonic themselves were talking up Plasma technology as being infinitely superior for active shutter 3D, the performance of the company’s LCD-based 3D TV displays is all the more surprising. In terms of resolution, the Panasonic TX-L42ET50B is superior to the manufacturer’s own Plasma TVs which have (all except one 2010 model) presented a slight resolution limitation in our tests. Like (nearly!) every active-shutter 3D LCD television we’ve tested, the TX-L42ET50 doesn’t skip a single pixel when it’s in 3D mode.

Gradation is better than 3D plasmas too: in fact, the TX-L42ET50B produced one of the most gorgeous 3D images we’ve ever seen. Unlike the plasma-based 3D TVs we’ve seen from Panasonic and Samsung, the 3D image is totally free of panel-generated dither noise, and unlike Panasonic’s Plasmas, is totally free of jaggedness during motion. Unlike Sony and Samsung 3D LCD televisions, there are no unusual pixel artefacts on the right-eye image (some Sony LCDs have suffered from an effect where parts of 3D images appear to have vertical lines running through them). Aside from some slight crosstalk, the quality in 3D display mode on the Panasonic ET50 is NOT worse than that in 2D, and that’s a serious accomplishment.

There are also no problems with motion, either – provided the 3DTV is set up correctly (the default settings are perfect in this regard). Like the 2012 Plasma TVs, users have the option of changing the [3D Refresh Rate] to either 100hz or 120hz, but leaving it in the “Auto” setting gives the best motion quality, because it avoids frame rate conversions.

Cloudy with A Chance of Meatballs

As with the 2011 Panasonic 3D LCD we checked out, we were pleasantly shocked by the lack of crosstalk on show. IPS LCD panels typically exhibit motion performance that’s excellent by LCD standards, with none of the low-tone smearing that we often see on competing PVA types. That superior motion performance pays off when it comes to avoiding crosstalk, due to the sequential nature of active-shutter 3D TVs. It also perhaps explains the lack of artefacts on the right-eye image (compared to VA LCD panels) we discussed earlier – perhaps the engineers have not had to resort to drawing this at lessened precision due to IPS’ superior motion performance.

It’s not all good news, though: the IPS panel’s greyish black levels are not entirely masked by the darkening effect of the 3D glasses. A positive spin on the same note, though: the 3D display mode has plenty of brightness.

Standard Definition

Standard-def content was upscaled well by the Panasonic TX-L42ET50. Scaling was excellent, with the ET50’s video processing getting the tricky balance between producing a crisp picture without excessive ringing around transitions just about right; only very mild ringing was visible, and we found the performance here to be bettered only by high-end AV receivers and video processors.

Diagonal interpolation was excellent, with only extreme angles (and edges) showing signs of jaggies. This means that video camera material (for example, sports games, news broadcasts) will appear without obvious jaggedness during motion. If we were being incredibly picky, we’d comment that there are subtle interlacing artefacts (scan-line like patterns) visible around the edges of bright colours, indicating an issue with chroma upsampling. But, talking about subtle chroma upsampling artefacts on standard-definition digital TV channels is a bit like crashing a car head-first into a brick wall and then mentioning that the back seat has a scratch on it; the overall quality is so low anyway (the fault of the broadcasters, not the TV) that it’s the least of our worries.

In terms of film mode tests, the TX-L42ET50B effortlessly detects and compensates for the most common and modern method of transferring film to PAL TV, which is great, and means that films on SD TV (or non-upscaling DVD players) will be reproduced with full clarity. The same excellent results were true of American-centric NTSC film tests.

High Definition

HD content from Blu-ray was pleasing on the Panasonic TX-L42ET50B. Brighter material was a real feast for the eyes thanks to the accurate greyscale, colour and freedom from obvious uniformity errors.

24fps film material was reproduced perfectly by the HDTV, with absolutely no judder. Resolution was perfect with real-world content, with full clarity being reproduced by the screen. There were no undefeatable attempts at smudging out film grain textures or other fine details. The accurate greyscale and colour performance resulted in largely untinted, natural video.

When we reviewed the first of Panasonic’s 2012 HDTVs, the ST50 plasma, we noted that in the Luma Zone Plate pattern we use to assess resolution, we could make out a slight “four leaf clover” shape in the middle of the screen. We weren’t sure if this was down to the driving of the plasma television, or if it was caused by the video processor chip. It appears on this LCD, too, ruling out the first theory, suggesting that it is in fact an attempt at selective picture sharpening on Panasonic’s part. However, we noticed absolutely no issues with real-life performance, and even on the zone plate pattern, the artefacts were subtle. We wouldn’t recommend any TV that featured obvious non-defeatable edge enhancement/sharpening, so rest assured, whatever’s going on, it’s not damaging real-world content to any visible extent.

Earlier, we specifically said that brighter material was a real feast for the eyes on the Panasonic ET50. Darker content is damaged by the IPS LCD panel’s contrast performance, which isn’t wonderful, as we mentioned before. With darker scenes, we did have to mentally tune out the slight greyness presented by the LCD panel, and remind ourselves what the intended effect of the cinematography was.

Console Gaming

Console gaming felt suitably responsive on the Panasonic TX-L42ET50, and we saw latency of just 24ms returned in testing. Although not the fastest we’ve ever seen, it’s on par with Panasonic’s higher-end Plasmas, and is enough to provide a very fluid response without noticeable “heaviness” in gaming. Panasonic’s and Samsung’s entry-level and midrange Plasma TVs are the fastest displays currently on the market, measuring at just 16ms, but we doubt many people would ever notice the difference between 16ms and 24ms. The 24ms figure, of course, is in the “Game” mode, which disables both [Intelligent Frame Creation] and some other “under-the-hood” motion processing.

As with the ST50 Plasma, the ET50 doesn’t deliver full chroma resolution from a source that supports it, such as a PC or video game console. Tiny coloured details appear slightly blurred, as they do on almost every television. This didn’t bother us, but ultra-observant (and ultra-picky) videophile gamers will want to check out LCDs from Sony and Samsung which do support this feature (some of the higher-end Panasonic 2012 HDTVs apparently do too, but we haven’t checked them out yet).

Online Features

Panasonic has expanded the VIERA Connect online service, which is accessed by pressing a large “Internet” button on the remote. Pre-installed apps include BBC News, Euronews, Netflix, FetchTV, Skype, Facebook and Twitter, and more (including a web browser) are downloadable. None of the film services are at the level of Blu-ray quality, in fact many are sub-Freeview and sub-DVD quality, although that’s not the TV’s fault.


The Panasonic TX-L42ET50B is a beautifully designed LED LCD TV with good picture performance and a great lineup of “Smart TV” internet features. Its key strengths and weaknesses are completely predictable for an LCD television using the IPS panel type – although the viewing angle performance is better than many LCD competitors, black levels are not a strong point of this technology, meaning that instead of absolute darkness, the ET50 can instead only display a dark greyish-purple shade.

However, the TX-L42ET50 has enough strengths in other areas for it to justify its existence in the marketplace. Compared to the LED LCD competition, it performed very well with regards to screen uniformity, with only a mild “mottled” effect visible with test screens, and basically no screen unevenness apparent with real-world content, meaning that it avoided the common edge-lit LED LCD flaw where the sides of the image appear brighter than the middle. And like all of the LED LCD TVs we’ve reviewed, it can produce a great amount of light in return for incredibly low power consumption, making it a good choice for exceptionally bright, sun-filled rooms. Its out-of-the-box picture accuracy was serviceable, and after calibration it was brought up another level – although nearly every name-brand HDTV on the market now does well in these areas, meaning these achievements aren’t unique.

It doesn’t reach the heights of Panasonic’s excellent 2012 Plasma range, but if you’re looking for an incredibly eco-friendly display with great internet features that can produce enough light to hold its own in a bright room, the TX-L42ET50B represents a good choice. And, once you get over the fact that IPS LCD technology isn’t capable of the same rich black levels, the 3D picture quality is actually better than the company’s Plasma range from the point of view of being free from artefacts. Accordingly, we decided upon a rating of “Recommended” based on the 3D strengths and the ET50’s other favourable attributes. If you don’t care for the third dimension, though, there are other LCD televisions with better black levels (allowing for a richer picture) for the same, or less money.


Back to: TX-L42ET50B Review

Professional TV Calibration Service

Own this (or any other) TV? Want to get the best picture quality? Book us in to calibrate your set. Affordable price... get a quote now.