Panasonic G20 (TX-P42G20) Plasma HDTV Review

AVForums investigates Panasonic's long awaited mid-range G20 NeoPDP HDTV.

by AVForums
TV Review

127

Highly Recommended
Panasonic G20 (TX-P42G20) Plasma HDTV Review
SRP: £1,099.00

Introduction

It's that time of year again - Spring is on the way, and another round of Panasonic HDTV displays is beginning to trickle into stores. In for review today is the long-awaited Panasonic TX-P42G20, the second iteration of Panasonic's affordable but powerful G-Series. At this level, you'll get the highly desirable 1920x1080p NeoPDP panel, a built-in satellite tuner which is capable of receiving the "Freesat" service, and new for this year, THX Display Certification, ISF calibration controls, and Freeview HD capability built in! We at AVForums have been waiting for these new and improved Panasonic displays for some time now, so without further ado, let's see what we have here!

Styling

I've used this phrase before, but it seems appropriate to use again - the G20 displays look rugged and built to last. The styling is decidedly plain and functional, which is no bad thing. The border around the screen is of medium thickness and is accented with a tinge of blue, which looks heavy and perhaps unappealing in promotional photos, but was barely noticeable in my own viewing environment (I would have described the TV as black if the slight blue hadn't been pointed out to me). The display is also very thin indeed, measuring around 5cm at its deepest point.

In terms of connectivity, the TX-P42G20 stands out above most current flat panel displays (which are all adequate for most users' needs) with the inclusion of a built-in satellite tuner. (There's also the aerial input which can now be used to receive Freeview HD channels, although competing displays will catch up in this regard over the next few months, whereas fewer manufacturers are providing satellite capability). The back panel features these inputs as well as 3 HDMIs, a set of Component video inputs with accompanying audio jacks, 2 SCART terminals, a PC "VGA" input, and an Ethernet (network) connector. The side of the TV features a 4th HDMI input, Composite video and stereo audio jacks, an SD card slot, and 2 USB connectors. Whew!

Menus and Set up

As AVForums readers will know, the UK versions of last year's Panasonic displays had a controversial omission: while the continental European models featured Greyscale and Gamma fine-tuning controls in the picture menu, these useful controls were missing from the UK models. This of course wasn't a deliberate snub on Panasonic's part, but more of an oversight which resulted from the Freesat-capable UK system software having a different development path within the company (the controls were forgotten, rather than deliberately left out). Thanks in part to the feedback from AVForums readers and like-minded enthusiasts, things are much improved this year.

The Picture setup menu has all the controls you'd expect: Contrast, Brightness, Colour, and Sharpness act as expected. Panasonic's "C.A.T.S." (Contrast Auto Tracking System) is present, which changes the light output of the panel to match the viewing environment. The "P-NR" noise reduction system also makes an appearance, but as before, this is a 2D filter which is not very effective (although I tend to leave TV noise reduction systems off, anyway, so it's no loss). "Picture Display" can be turned Off to turn the Plasma display off, keeping the TV's speakers active – useful for power saving if you're between rooms but still want to hear a broadcast.

If you receive your new G20 and don't see the "Advanced Settings" menu, don't panic – it's there, but just has to be enabled. A trip into the Setup menu will reveal the "Advance(isfccc)" option; turning this on will unlock the Advanced controls as well as two new picture preset modes: Professional1 and Professional2.

Since we're already in the Setup menu, it's worth discussing the other picture controls hidden in here in the "Other Settings" submenu: "Intelligent Frame Creation" (which becomes "24p Smooth Film" with a 24p input signal) is a frame interpolation system which should be left Off for the highest and most accurate picture quality. The naming of "24p Smooth Film" has caused great confusion over the last few years, but know this: if your Blu-ray Disc player is sending 24p video to the TV, you must leave this control OFF to see 24p! Confusing? Absolutely. If you turn "24p Smooth Film" to ON, then the TV generates additional inbetween frames (which were never part of the film in the first place) and slips them into the video signal, producing a higher frame rate which was not intended.

There's a "Resolution Enhancer" control, which applies controlled high frequency sharpening, designed to increase the perceived detail of SD content (the effect is fairly subtle). Finally, there's "16:9 Overscan", which should be turned Off to produce maximum clarity with 1080i and 1080p signals.

Back to the "Advanced Settings" in the picture menu: Panasonic now provide full control over Greyscale (called "White Balance" in this case), and a limited, but still potentially useful Colour Management System. This is a 2D CMS which allows control over Primary colours only, and we'll see how effective it is later in the review process. Finally, a Gamma curve (the distribution of light between black and white) can be selected. The options are the milky-looking 1.8, 2.0, the default 2.2, 2.4, 2.6, and "S-Curve". I'll discuss this in more detail during the Calibration.

One last thing: in the "Professional1" and "Professional2" picture modes, all of the settings are now saved per-input (even the Greyscale, Gamma, and Colour Management ones). So, you can, for example, add more Sharpening to blurry TV broadcasts, but keep Sharpening off for sources that don't need it, such as HD games consoles and Blu-ray Disc players.

Features

As well as featuring HD satellite and terrestrial capability, the G20 has some additional handy features. There's VIERA CAST, which, when connected to your home router by network cable (or by the optional wireless add-on dongle), allows you to access news coverage, as well as versions of Skype (complete with video conferencing, provided you connect the optional camera accessory to the TV), and Twitter.

There's also Hard Drive PVR functionality, too. Hook up a USB hard disk to the TV and you'll be able to grab TV programmes from the airwaves and store them on a USB hard disk. You'll also be able to Pause Live TV in a similar manner. Unfortunately, the TX-P42G20 appears to be a little choosy in what USB hard drives it will accept, and refused to play ball with the USB disks I built myself out of old hard drives and external hard drive shells. However, store-bought drives worked nicely. Consider the price of an external PVR and then also consider that many of us will have a USB hard drive lying around that we can devote to this cause, and you'll understand why I think this is such a fantastic added-value feature. (By the way, because the TV doesn't have it's own video encoder inside, the programmes you save to hard disk are the same quality as the original broadcasts - no recompression goes on.)

Test Results

Measured Results Out of the Box (THX Mode)

Note: during the initial review process of the Panasonic TX-P42G20, the colour performance measured as "Good", having largely correct Hue and Saturation properties, but including Luminance (colour brightness) errors. After more hours of "run-in", these errors have disappeared (almost) entirely, making way for "Excellent" performance. Because these properties appear to improve rapidly after turning a new unit on, we have modified the review as necessary.

Like last years' V10 series displays, the lower-down G20 model now also features a THX Picture Preset mode. This mode attempts to present the highest quality, most accurate picture with the touch of a button, and is great for users who want high picture quality, but are not necessarily willing to spend money on a calibration (or learn how to calibrate for themselves). I started by measuring the accuracy of the THX mode.

As we can see from the above chart, the THX mode does a decent job of producing near-accurate Greyscale, but it's not perfect. This is because each individual television is different; the characteristics of the panels themselves vary from unit to unit. THX's settings are not tailored to your individual television (and other equipment in the chain!) like an ISF calibrated TV would be. Regardless, the colour temperature is quite close to the desired 6,500K (it hovers around 7,000 for the most part, as seen in the top-left box).

The colour accuracy of the THX mode is excellent for a pre-set mode. Barring a small error with Magenta hue and Green saturation, all of the colours (the black points on the chart) are extremely close to standard. This is just about as much accuracy as we can hope for from a non-calibrated picture preset.

Let's see how much this result can be improved with Panasonic's newly added calibration controls in the next section:

Calibrated Results

When the TV is in the THX picture preset, the user is allowed to alter Greyscale and Gamma, which is excellent, but if we step up to the Professional1 or Professional2 picture modes (which, before tweaking, look identical to the THX mode anyway), we can also access the Colour Management System. So, I selected the Professional1 mode and then began calibration.

Thanks to the user-accessible calibration controls, I managed to calibrate the Greyscale on the TX-P42G20 very quickly. I also tried some alternative calibration strategies to see if these would bring different results, but all of them were equally good. Previous UK Panasonic displays have had these controls hidden away in an engineer's menu, which I now had no reason to touch. The result is remarkably accurate Greyscale (if it doesn't look accurate to you on the RGB Colour Balance chart, pay attention to the scale at the left – those variances are really only a few percent!)

Gamma tracking is less exact, which is a little irritating, but not surprising: no Panasonic Plasma I've ever measured has has ideal Gamma (ideal in this case would be flat 2.2 at each stimulus). With this said, I'm personally quite forgiving of small inaccuracies here, and I'd need a 100% correct display beside this one to pinpoint the errors. I tried changing the Gamma option in the user menu between the various different presets, but the default "2.2" preset (which measured closer to 2.1 on this particular TV) was the most accurate, so I left it as-is.

After run-in followed by calibration using the Colour Management controls, the colour performance is absolutely excellent. This is a 2D CMS system and only affects primary colours, so is limited compared to competitor's implementations, but the additional controls are really not too sorely missed as the results are still absolutely excellent. All of the colours are correctly saturated and are on-hue, barring very, very minor errors with blue and magenta. Luminance readings are also very good, with discrepancies from the ideal so small that they barely add to the measured Delta Error (top left in the image) for each colour. Again, this is an absolutely excellent result.

Video Processing

One of my biggest criticisms of last year's Panasonic displays (except for the extremely expensive Z1, that is!) was the lacklustre quality of the TV's scaling when the TV was fed with a 480i or 576i source. In other words, when the TV was fed a standard definition signal, the on-screen picture was somewhat blurry, because the TV wasn't preserving all of the high frequency content in the signal. This is now a thing of the past, as the scaling on the G20 is fantastic. The smallest details of SD sources are preserved and are presented on-screen without blurring or ringing. The resulting clarity is very close indeed to products using the high-end HQV scaling chip (seen in some AV receivers and premium Blu-ray Disc players).

Scaling (the actual "resizing") of SD signals is just one part of making them watchable on HD flat panel displays, however. I also tested the Panasonic TX-P42G20's diagonal interpolation and film mode detection capabilities. First, diagonal interpolation, in other words, how well the TV suppresses jaggedness in standard def material. The TX-P42G20 did a good job, consistent with other displays in this price range (and above). For those of you familiar with the "three rotating bars" test pattern on the HQV test disc, the top two moving bars were smooth except for some jaggedness at their edges, and the bottom line was fairly smooth, indicating good performance.

As with last year's Panasonic Plasmas, film mode detection is non-existent on the TX-P42G20. This means that all film content (regardless of whether it's been transferred to European-centric PAL or American-centric NTSC format) is processed by the TV in the same way as Video camera material, which produces small flickering in finely detailed areas. As with last year's models, although this is slightly irritating, it's important to put it in context. The TV's own Film Mode detection is only relevant when you are feeding an interlaced standard-def signal into the TV (such as from an SD satellite or cable box, or from the TV's own built-in Freeview or Freesat tuners). If you are using an upconverting DVD player, the TV's film mode detection is bypassed and the resulting picture quality depends on the film mode detection capabilities of the player.

Gaming Performance

I measured the TX-P42G20 as having around 21ms of input lag when compared to a lag-free CRT computer monitor. This result was consistent regardless of which picture preset the TV was operating in – that is to say, the "Game" mode on this display appears to be largely for marketing purposes. This is not surprising, because as a Plasma display, the G20 produces clear motion naturally and does not have to resort to additional response time compensation processing like an LCD would. As a result of this low figure, games were fluid and fun. (An interesting psychological effect of low input lag is that the game feels like it's running at a smoother frame rate, if you're used to playing it on a lagging screen).

I had a ton of fun playing the gorgeous 2D sidescroller "Muramasa: The Demon Blade" on the Nintendo Wii thanks to this low amount of lag. On top of that, the excellent scaling and motion resolution played a part: this game runs at a constant 60 frames per second in 480p resolution, and is exactly the sort of video game material that can reveal the limitations of a display. The high motion resolution of the panel was readily apparent, and in fact, the motion clarity with this game was just as good as the Pioneer PDP-LX5090 that I experienced it on before, with only tiny green/yellow trails being visible with fast motion. Additionally, the clear scaling and a tiny bit of in-TV sharpening made the absolute most of the standard definition source material.

Despite the fact that this game features almost permanent on-screen counters, I had absolutely no image retention even after many hours of play.

It's also worth noting here that at all times, the TX-P42G20 displayed video signals in 4:2:2 format. This means that the coloured components of the picture are at half-resolution; a common shortcut used in the video world, which takes advantage of the fact that our eyes are less sensitive to colour in relation to brightness. (DVD and Blu-ray Disc video uses even lower chroma resolution, which is why TVs processing the video at 4:2:2 is generally fine). I mention this in the gaming section because games consoles can output full resolution colour (4:4:4 format). When input to this display, the chroma resolution will be downgraded. This is a little surprising, because Panasonic themselves are some of the biggest advocates I can think of of high-resolution chroma processing - they make a point of publicising it when present in their Blu-ray Disc products.

Energy Consumption

The amount of energy consumed by a Plasma display is proportional to the luminance of on-screen images. For example, a dark scene will use less power than a fully white screen. Most video content falls somewhere in the middle, so pay most attention to the reading for "Grey Screen" below. Here's how the TX-P42G20 fared after calibration:
Black screen (0 IRE): 65 watts
Grey screen (50 IRE): 154 watts
White screen (100 IRE): 292 watts

Picture Quality

The picture quality of the Panasonic TX-P42G20 is absolutely excellent. As with last year, this is largely due to the quality of the NeoPDP panel in the display, which is responsible for many of its best attributes. The display produces a very, very deep shade of black which is not at all far behind the current state-of-the-art, something that I still find extraordinary on such an affordable HDTV (Panasonic has associated the G20 with the promotional tag "Infinite Black"; whereas their flagship model this year will carry the "Infinite Black Pro" branding).

Of course, the level of black depends on the ambient light in the room. If you have sunlight shining directly onto the display, blacks will look somewhat grey as a result, as the ambient light filter on the panel does not entirely reject surrounding illumination. Where the G20 really shines is in darker environments.

Moving on, the motion clarity completely smokes any competing LCD display, regardless of whether those LCDs are equipped with a 100hz/200hz system: the NeoPDP panel naturally produces clear motion in almost all situations without having to resort to such video processing, so your High Definition TV will still have High Definition when the picture is moving (as television pictures tend to do!) With certain material (typically high motion video camera content), posterisation is still sometimes becomes visible during fast camera pans, but overall I find this effect, which only appears with certain types of material, much less disturbing than the indiscriminate blur of an LCD.

Furthermore, Plasma panels do not have the viewing angle fall-off issues that most LCDs do. As a result, the colours and richness in the image do not degrade when you view the TV from the sides.

In comparison to other Plasma displays, the G20 also has a lot to offer. First of all, in comparison to our current state-of-the-art reference display (the Pioneer KURO PDP-LX5090), the Panasonic panels have considerably less panel-generated noise in the image. This is most noticeable with synthetic content like animation or computer graphics, which have a cleaner, silkier appearance, especially if you are sitting close to the screen as you might do while playing video games. And in comparison to Plasma products from LG and Samsung, the Panasonic, like the Pioneer, does not suffer from obvious image retention (which is where static on-screen images, such as TV station logos or score counters in video games hang around temporarily even after you've stopped viewing them).

The calibrated colour accuracy in the Professional modes (and the near-calibrated quality as seen in the THX mode) also greatly benefits the image quality. When correctly configured, the images you see on the TX-P42G20 are as perfect a match to what the filmmakers and programme producers intended as we could hope for at this price point. Most of the colours had an error of around 1 (in other words, forget the error exists), with only Green having an error of around 2 (making it barely perceptible for the most seasoned eyes). This is a quantum leap over the colour accuracy of last year's G10 displays, which featured an oversaturated gamut in all modes, albeit not an outlandishly garish one.

Also, it's worth noting that the G20 displays 24p input signals at a multiple of the frame rate, meaning that they display without judder or stutter.

Verdict

8
AVForumsSCORE
OUT OF
10

The Good

  • Produces a very deep shade of black
  • Excellent motion resolution: video remains crisp even in motion
  • Low amount of PWM (panel generated) image noise
  • Built-in tuners for both Freeview HD and Freesat HD
  • SD material looks just about as crisp as possible thanks to excellent scaling
  • THX picture preset provides a "best endeavour" scenario for users who don't want to pay for a full calibration
  • "Advanced Settings" screens allow convenient fine-tuning for calibrators to maximise picture quality
  • Post-calibration Greyscale is very accurate
  • After a small amount of run-in and calibration, colour accuracy is also fantastic
  • Low input lag makes video games very enjoyable
  • Hard Drive PVR functionality is a fantastic added-value feature

The Bad

  • Gamma tracking is closer to 2.1 than the ideal 2.2
  • Film mode detection is still non-existent: be sure to bring your own upscaling DVD player!

Panasonic G20 (TX-P42G20) Plasma HDTV Review

Last year, the original Panasonic G-Series NeoPDP displays brought us deep blacks and contrast performance previously unheard of at their price range. While the TX-P42G20 doesn't reinvent the wheel, it is a considerable improvement on last year's G10 models in just about every conceivable way. In fact, with the previous small colour inaccuracy issues no longer present, it's safe to say that other than slightly deviated Gamma (which will be an invisible quirk to all but the most die-hard videophiles), the Panasonic TX-P42G20 has no significant flaws whatsoever. If you're looking for an excellent, feature-laden TV at an excellent price, you do not need to look any further. Thanks to Panasonic's somewhat unique usage of Plasma display technology (something we wish more companies were involved in) and the newly added calibration controls, it is safe to say that Panasonic's TX-P42G20 will almost certainly remain the best HDTV at this price level for some time to come. I cannot wait to see what Panasonic have in store for the higher-end models this year. Highly Recommended.

AVF Editor's Note:
This review and the outcome is based on fully testing the TV we had for review. However, it should be noted that some 2009 models are reported by users as suffering from an issue where black levels rise and image retention is seen. This seems to affect a small (reported on AVForums) number of 2009 TVs in the UK where the issues have been reported to Panasonic. There is no evidence that we have seen with this review sample that the same will occur with 2010 models, although a Panasonic statement in the US states that the technology which is alleged to cause the issues is the same as the 2009 TVs - we have no evidence of this being the same with the UK 2010 TVs at this moment in time. We have also made Panasonic UK aware of the issues for the 2009 TVs. Because of legal issues Panasonic UK has declined at this moment in time to comment further - However readers please check the Plasma TV forum for user feedback of this TV by owners. Again we saw no evidence with the review sample and can only report on the data we have without speculation. No official announcements have been made to date from Panasonic UK confirming or denying these reports of issues with 2009 sets on AVForums or elsewhere.

Highly Recommended

Scores

Sound Quality

.
.
.
7

Smart Features

.
.
8

Ease Of Use

.
.
8

Build Quality

.
.
8

Value for Money

.
.
8

Verdict

.
.
8

Picture Quality

.
.
8

Video Processing

.
.
.
7

Greyscale Accuracy

.
9

Colour Accuracy

.
.
8

Contrast/Dynamic Range/Black Level

.
9

Screen Uniformity

.
9
8
AVForumsSCORE
OUT OF
10

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