LG PX990 (50PX990) Review

Steve Withers takes a look at the LG PX990, the world's first THX certified 3D display

TV Review

274

Highly Recommended
LG PX990 (50PX990) Review
SRP: £2,150.00

Introduction

Like many manufacturers LG has been at the cutting edge of new display technology; but unlike some LG has also placed importance on accurate image quality and professional calibration controls. All of LG’s 2010 displays include ISF calibration controls and many also include THX certification and pre-calibrated settings. So it came as no surprise when at IFA in September, LG announced the PX990, the world’s first THX certified 3D display. In the absence of any current industry standards for 3D, the introduction of a THX certification process is an important step in the evolution of 3D as a domestic format and I was very interested in putting the PX990 through its paces.

Styling and Connections

Given that the PX990 is LG’s flagship plasma you would expect sleek design and high quality build and that’s exactly what you get. The display consists of a single sheet of glass at the front behind which there is the screen surrounded by a black bezel that is 4cm wide at the top and sides and 8cm wide at the the bottom. It is no surprise that the use of a single sheet of glass is popular with display designers, it is very sleek and stylish but the obvious limitation of this approach is reflections caused by ambient light in the viewing room.

The PX990 is actually much better than many of the other displays that I have reviewed but it did still suffer from occasional reflection when there was a lot of ambient light in the room. There are symbols on the glass at the bottom left of the screen which are actually touch sensitive controls for basic functions like on/off, volume and channel and the infrared sensor is also located here. Behind the glass front along the edge of the display is a dark blue strip that connects to the back of the chassis which is made of black metal. The overall design is very attractive and for a 50” plasma the PX990 is surprisingly thin, measuring only 5cm deep. To compliment the modern and sleek design is a black metal and glass stand that provides stable support and can be swiveled if necessary.

The supplied remote is the latest iteration of the standard glossy black LG design and personally I really like it. The remote is sensibly laid out, even more so now that the button for the EPG is better positioned, which suggests that LG have been listening to our feedback. The remote is also comfortable to hold, has back light illumination and is intuitive to use with buttons for all the key controls including Menu, Guide, NetCast and 3D.

The PX990 also comes supplied with one pair of rechargeable active 3D glasses and a USB cable for connecting the glasses to one of the USB sockets on the display for charging. The glasses themselves are a fairly standard design and are large enough to fit over another pair of glasses if you wear corrective lenses. However I think the glasses could do with blocking out more light at the sides, the lenses themselves could be bigger and I found them heavy and uncomfortable to wear for long periods of time.

As one would expect from a high end display the PX990 includes a generous set of connections. At the back there are three HDMI inputs, as well as an aerial socket, a SCART socket, a component video input with left and right analogue audio RCA connectors, a LAN socket, a VGA input, a digital optical out, a RS232 interface, an audio in and a wireless control socket. The back connectors on the PX990 face outwards but I still feel that if they faced downwards it would allow for easier wall mounting of the display and tidier cable management.

At the side there is the standard Common Interface card slot, an additional HDMI input, two USB ports and a composite video input with left and right analogue audio RCA connectors. The side connectors are recessed by 11 cm which is a good idea because it avoids unsightly wires poking out the side of the display and is deep enough to comfortably hide the supplied WiFi dongle.

Menus

The main menu page gives you a series of ten options each represented by an appropriate icon. The icons available are: Set Up, Picture, Audio, Time, Lock, Option, Network, Input, My Media and Game. I’ll address Set Up, Picture and Audio in more detail later but as for the other choices, Time relates to setting the time as well as the timer and sleep mode functions and Lock controls the parental lock. In addition there is Option which offers a series of generic controls for functions such as language, Network which allows you to set up the internet connection, Input which obviously allows the user to change between inputs and label them, My Media which allows the user to watch content via the USB input and Game which provides access to a number of simple games.
The actual set up of the display was very easy with the Freeview channels being tuned in about 5 minutes. The resulting EPG is well laid out and easy to use with an attractive design that is semi transparent, appearing over the channel you are watching; there is also still audio as you navigate through the channel choices which is good.

Within the Picture menu there is an option for choosing the Aspect Ratio and where possible always use the Just Scan selection as this will pixel map the incoming signal exactly and thus avoid any overscan or unnecessary processing. There is also an Energy Saving function but all this does is dim the picture and is best left off. The Picture Mode gives you a choice of a number of different settings including the usual Vivid, Standard, Sport and Game. There is also a setting called APS (Auto Power Save) which was previously called Intelligent Sensor and adjusts the image depending on the ambient light in the viewing environment. As with the Energy Saving function, APS is best left off by anyone who is seeking an accurate image. Probably of more interest to the AV enthusiast is the inclusion of two THX presets, one called THX Cinema which you can use at night or in a light controlled room and one called THX Bright Room which you can use for daytime viewing. There are also two ISF settings Expert1 and Expert2 which a professional calibrator can use to access advanced picture controls and then lock once they are finished. There are two settings because much like the THX presets you can create one for daytime viewing and one for nighttime viewing.

In ISF Expert1 or Expert2 there is also the Expert Control option which gives the professional calibrator access to an impressive array of picture controls. There is a Dynamic Contrast which seeks to boost the contrast ratio by changing the Brightness and Contrast controls on the fly and is best left off. There is a Noise Reduction control but I found it didn’t really improve the picture and was best left off. The Black Level function should be left on Low and the Film Mode function controls the deinterlacing of film based material and where possible should always be left on. The Colour Gamut offers a choice of Standard and Wide and the Edge Enhancer acts much like a sharpness control and just like any other sharpness control it should be left off.

The Expert Control also allows you to select the Colour Temperature, the choice is between Warm, Medium and Cool and here I found Warm to be the most appropriate. There is also a control for Gamma which provides a choice between Low, Medium and High and here I found that Medium best approximated a gama of 2.2 which is the target we use in our reviews here at AVForums. The PX990 has both 2 point and 21 point White Balance controls, I selected the 21 point option which should allow me to very accurately calibrate the Greyscale and Colour Temperature.

Finally within Expert Control there is a Colour Management System (CMS) that should allow you to accurately calibrate the Colour Gamut. In the CMS that LG has built into the PX990 there are controls for the three Primary Colours (Red, Green and Blue) and the three Secondary Colours (Cyan, Magenta and Yellow). The actual controls are Colour which sets the saturation and luminance and Tint which sets the hue.

Since the PX990 is a 3D display there is a menu dedicated to the 3D settings which can be accessed via a button on the remote but it will also pop up when the display detects a 3D signal. This menu allows you to choose between 2D to 3D conversion and the different 3D delivery systems including side by side, top and bottom, checkerboard and frame sequential.

Features

As you would expect from a flagship display the PX990 comes with a host of features, the most obvious of which is 3D capability. The PX990 uses the active shutter method to produce full 1080p 3D images from Blu-ray sources. The PX990 is shipped with one pair of rechargeable 3D glasses included but unless you live on your own and have no friends you will obviously need to buy more.
The major new feature on the PX990 is the addition of THX 3D Certification and as previously mentioned the PX990 is the world's first TV to have achieve THX 3D Display certification.

The PX990 includes LG's 600Hz Plasma technology to reduce zero motion blur and increase response time and the addition of the TruBlack Filter blocks glare and reflections on the TV screen to enhance and improve picture quality and contrast. This means you should be able to enjoy improved black levels and a distortion free viewing experience even in brightly lit rooms.
LG’s NetCast Entertainment Access brings the best of the internet directly to your TV, without the need for a computer. You can enjoy YouTube videos, weather forecasts from Accu Weather as well as online photo sharing through Picasa from the comfort of your living room sofa. You can access this service by connecting the PX990 to your home network either via the built-in Ethernet port or using the supplied Wi-Fi USB dongle. With LG NetCast TVs you will also be ready for selected future online services which can be updated directly on to your PX990.

As is largely standard now, the PX990 includes a built in Freeview HD tuner, so if you live in an area that receives high definition broadcasts you can enjoy BBC, ITV and C4 in high definition with no need for a satellite dish, monthly fee or contract.
The PX990 is fully DNLA compliant for streaming content across your network or connecting your digital camera, MP3 player or flash memory through the USB port to watch videos, listen to music or look at photos; finally it also includes DivX HD.

Test Results

All measurements were taken after the PX990 had been run in for at least 100 hours and for this test I chose the THX Cinema mode which should represent the most accurate of the pre-calibrated presets. When you choose the THX preset it automatically selects Just Scan, turns off the Energy Saving function and any other ‘enhancement’ features. In addition the THX presets are locked out to prevent anyone changing the settings and I’m not sure this is such a good idea, especially with regards to the Contrast and Brightness controls. Ideally people should be able to choose the THX mode and then set the Contrast and Brightness settings based upon the viewing environment. Using a PLUGE pattern I could see that the THX Brightness setting of 50 was actually too low and in fact the best setting was 52 for my viewing environment but I wasn’t able to change it.

This is a shame because one of the most useful features that LG include on their displays is the Picture Wizard which helps the user set up their display correctly. In the set up features of some manufacturers the user is asked to choose between two images and ‘pick the one that looks best’, this is absolutely the wrong approach to calibration. LG in comparison uses test screens and tells the user what they should be looking for in order to correctly calibrate the Brightness, Contrast, Tint, Colour and Sharpness. The Picture Wizard is easy to use and surprisingly effective at completing a basic calibration if you don’t have access to a signal generator or a calibration disc.

One area that LG has come under criticism for is unnecessary sharpness that couldn’t be defeated but it appears that LG has listened to feedback and fixed this. Using a sharpness test pattern produced by my MP500 and leaving the sharpness controls at 50 I had a perfect image with no ringing or softness.

Given how accurate the THX preset was on the LG LE8900 I was surprised that the THX setting on the PX990 wasn't more accurate. There were DeltaEs of over 3 in most of the IRE intervals and DeltaEs of over 5 in 40, 60 and 90 IRE which would be noticeable as discolouration on a stair step test pattern. Red is tracking consistently over the target of 100 whilst both Green and Blue are tracking below the target. The Gamma tracks quite closely to our target of 2.2 up to 70 IRE at which point it peaks at 2.5 but this probably wouldn't have any noticeable affect on the image. It is possible that these inaccuracies are a result of the PX990 needing to be run in for longer but it is a shame none the less.

As with the Greyscale, the Colour Gamut wasn't as accurate in the THX preset as I had come to expect from LG displays. The Luminance DeltaEs were quite good with all but Blue below 5 but Green was over saturated and both Red and Blue are under saturated with Red also showing a large error in Hue which resulted in reddish flesh tones. Considering the LE8900 had one of the most accurate out of the box colour gamuts I have measured I was hoping for better results here but once again it might be that the panel needs to be run in for longer.

For these measurements I used the ISF Expert1 setting and then set about ensuring that my basic controls were set correctly. As with the THX mode I chose Just Scan and turned off all the picture processing features but unlike the THX mode I was able to correctly set the Brightness setting to 52 (the Contrast setting was 80 which was the same as the THX mode). As I had already established the best setting for the sharpness controls I left them centred at 50 and I also left Colour and Tint controls centred too since I intended to use the CMS. I chose the Warm setting for Colour Temperature, Medium for the Gamma setting and Standard for the Colour Gamut. Unfortunately this is a step back when compared to the LE8900 which offered more precise settings for Gamma such as 2.2 or 2.4 etc and more choices for Colour Gamut including Rec709.

The addition of a 21 point White Balance control allows a professional calibrator to set the greyscale using intervals of 5 IRE. This offers an unprecedented degree of control and whilst time consuming allows the greyscale to be calibrated to DeltaEs of less than 0.5 which is essentially perfect. As you can see from the graph the DeltaEs from 100 IRE down to 25 IRE are all less than 1.0 and the errors below 20IRE are more a limitation of my meter than a problem with the display. The Gamma curve is also tracking more closely around 2.2, especially at 80IRE. As a result of the calibration a stair step pattern looked very good with a nice smooth transition from black to white and no discolouration. This is a reference performance from the PX990.

The colour gamut was also much improved after calibration, although still not quite as accurate as I would have liked. Part of the problem lies with the CMS itself which only has two controls, one which sets Hue and one which sets Colour (Luminance and Colour) ideally a CMS should control Luminance, Colour and Hue individually. As you can see on the graph the reference greyscale performance is reflected in the accuracy of white which is smack on D65. The overall accuracy is very good with all the colours except Blue having a DeltaE of less than 3 which is indistinguishable to the human eye. The Luminance measurements were also excellent which is the most important of the three components of colour and the overall DeltaE in Green was very small which is good as this is the colour the human eye is most sensitive to. The only colour that had any substantial error was Blue but this is the colour the human eye is least sensitive to so it shouldn't be noticeable. Red was also more accurate now and this resulted in much more realistic flesh tones. Overall this was an excellent performance but I would like to see LG introduce a full CMS in their 2011 range of displays.

Calibration for 3D viewing remains problematic in the absence of any established industry standards. The two main problems with 3D calibration are light loss and colour shift and thus any calibration approach needs to address these issues. The problem of light loss is best addressed by simply increasing the light output of the 3D display as much as possible without introducing any clipping. Adjusting for the colour shift is a bit more difficult and ultimately the most effective way is to actually take readings through the 3D glasses in order to compensate for the colour shift they cause. The addition of a THX 3D preset certainly helps in this area because THX are trying to ensure that the display produces a 3D image that is both bright enough and accurate enough whilst also ensuring there is minimal crosstalk.

Video Processing

Overall the performance of the PX990 was very good in the video processing tests and once again it would appear that LG have been listening to feedback and fixed a few minor points raised in earlier reviews. As usual I started with my PAL and NTSC HQV benchmark discs and first of all I checked the SMPTE colour bar test which the PX990 easily passed, correctly scaling the full 576i and 480i images without any loss of detail or unwanted ringing. The PX990 also scored well when it came to video deinterlacing with jaggies only appearing when the line was at an acute angle in the first test. In the second test the motion adaptive deinterlacing was also good with slight jaggies only appearing on the bottom bar of the three moving bars. This is a better performance than on earlier LG displays that I have tested so clearly LG have made some improvements here.

The PX990 performed well in the film detail test and correctly locked on to the image resulting in no aliasing in the seats behind the race car in the classic speedway test footage that both HQV and Spear & Munsil use. In the cadence tests the PX990 correctly detected both the 2:3 (NTSC - USA/Japan) format and the 2:2 (PAL - European) format which once again is an improvement on earlier displays that failed to properly detect 2:2 cadence. The PX990 also correctly displayed film material with both horizontal and vertical scrolling video text, correctly displaying the words without any blurring or shredding. This is another area where previous LG displays have failed so full marks to LG for making these improvements.

The PX990 also performed very well in all of the tests on the HQV Blu-ray using high definition content. With the player set to 1080i the display correctly deinterlaced and displayed both the video and film resolution tests (provided the aspect ratio is set to Just Scan) and showed good scaling and filtering performance as well as good resolution enhancement. The PX990 also had no problems in showing video text overlaid on film based material and also handled 24p content without any problems.

I am a big fan of the Spears and Munsil test disc and find myself using it more and more these days as it contains a host of useful tests and is very easy to navigate (which is a nice change after the original Video Essentials DVD which was a nightmare). The menu system is sensibly laid out and intuitive to use, there are explanations for all the tests and it includes some excellent high definition demo material. I would strongly recommend it to anyone wishing to correctly calibrate their own display or test its performance. There are a number of very handy test patterns but two of the most useful are designed to clearly show video levels up to peak white and down to reference black. The headroom performance of the PX990 from reference white (video level 235) up to peak white (video level 255) was very good and there were absolutely no signs of clipping. In addition the PX990 also correctly showed detail down to a video level 17 and then nothing below that down to video level 0 which represents reference black.
Overall this is a great set of results and I’m especially impressed that LG appear to have addressed every video processing issue that I raised in my review of the LE8900.

Gaming Performance

Unlike most of the plasmas I have tested the LG models tend to have rather high input lags and the PX990 is no exception. In THX mode the input lag measured at 80ms although in Game mode it fell to 40ms which is fine for me but probably a bit slow for hardened gamers. Using Game mode combined with the 2D to 3D conversion feature the input lag increased to 90ms so anyone thinking of playing 2D games this way should be aware of the additional lag.

Energy Consumption

As is the case with all plasma displays the PX990 uses a self illuminating technology so the power consumption varies with the content being shown on screen. Therefore high contrast white background material will use more power to create an image whilst darker scenes will use less. There is an Energy Saving function on the PX990 but for the reasons I mentioned earlier, I would leave this off. In fact in its calibrated mode the PX990’s energy consumption was surprisingly even and efficient for a plasma with the highest measured figure for normal viewing content at 280 watts, the lowest at 150 watts and the average was 250 watts. The consumption figures at 0, 50 and 100 IRE rasters in the calibrated picture mode were 50 watts, 220 watts and 330 watts and the PX990 used less than 1 watt in standby.

Picture Quality - 2D

When it came to watching real world material the accurate greyscale and colours really paid dividends with images that were realistic and detailed. The high definition footage on the Spears & Munsil disc looked spectacular with natural colours, great shadow detail and exceptional levels of resolution. Watching Blu-rays was also a revelation with the PX990 handling the 24p signal without any issues and some of the concert footage I watched on BBC HD looked wonderful with vibrant colours and amazing detail.

With standard definition material the excellent video processing resulted in images that were free of scaling and deinterlacing artefacts, especially when watching DVDs. The internal Freeview tuner also produced very nice images but even the PX990's great processing couldn't do much for some of the more compressed digital channels.

There were almost no signs of image retention and the off-axis performance was excellent and being a plasma motion looked very natural. There was some PWM noise but this is normal for a plasma and at a sensible viewing distance the noise was completely invisible.

If there is one weakness with LG plasmas it has always been the blacks and whilst the TruBlack filter certainly helps, the blacks still aren't as good as Panasonic but then at least the PX990 can display 50Hz material correctly. The TruBlack filter also helped reduce reflections which was useful considering the front of the display is a sheer sheet of glass. I'm also glad that LG has resisted the urge to shut the screen off when the screen isn't receiving a signal. Other manufacturers use this global dimming trick and it's just a blatant attempt to boost their contrast ratio numbers.

Overall the PX990 produces a very pleasing 2D image no matter what you are watching but with high definition sources it really shines, producing some spectacular images.

Picture Quality - 3D

I was lucky enough to spend some time with guys at THX who designed the 3D certification programme so I know how rigorous it is and clearly this effort has paid off. The first area of importance for THX certification is to ensure there is a bright enough image when wearing the glasses in 3D mode without introducing clipping or discolouration. Whilst the was still a reduction in image brightness when watching 3D material the image was certainly bright enough to be enjoyed and appeared free of clipping or discolouration. The second area is to ensure colour accuracy by taking into account the glasses themselves. Since my meager 3D Blu-ray collection consists entirely of CG animation colour accuracy was more difficult to assess but I used a friend’s 3D camera to create some 3D material of my own and using this material I could see that flesh tones appeared accurate. The third area relates to the performance of the glasses themselves and ensures there is no crosstalk or loss of synch when using active shutter glasses. The amount of crosstalk was minimal as I would expect with a plasma and I never experienced any problems with the glasses synching to the TV and they also tolerated a fair degree of head movement.

In general viewing tests all my 3D Blu-rays looked very good in THX 3D mode, with bright and vibrant images. The main problem remains a lack of content and even though ‘Cloudy With A Chance Of Meatballs’ is a cute movie, you can only watch it so many times. However things seem to be improving with new 3D Blu-rays announced for December and those with access to SKY 3D will at least be able to watch those broadcasts. In addition camera’s like the one I borrowed from my friend will help generate new 3D content.
Like all the other manufacturers LG includes a 2D to 3D conversion function and like all the other conversion modes I have tested the one in the PX990 doesn’t really work. Just as images begin to take on a genuine degree of dimensionality something in the image will confuse the software and the illusion is ruined. So no matter how desperate you are for 3D content I really wouldn’t bother with the 2D to 3D conversion, it really is just a gimmick.

The only possible use for 2D to 3D conversion is with 2D games but even then the effect pales when compared to actual 3D games. I have become quite addicted to Super Stardust in 3D, it is a simple game that makes imaginative use of 3D and the added dimensionality really adds to the fun.

Verdict

8
AVForumsSCORE
OUT OF
10

Pros

  • THX Cinema provides an accurate preset
  • Reference greyscale performance after calibration
  • Reference colour accuracy after calibration
  • Full ISFccc calibration controls
  • 20 point white balance controls
  • Colour management system
  • Freeview HD built in
  • Very well designed and responsive menu system
  • Attractive styling and well designed remote
  • World's first THX certified 3D display
  • Superb build quality and design
  • Excellent video processing
  • Very little crosstalk
  • Almost no image retention
  • Excellent off-axis performance
  • One pair of 3D active shutter glasses included
  • WiFi dongle included

Cons

  • Internet platform is rather limited
  • Input lag could be better in Game mode
  • Downward facing HDMI inputs would make more sense on an ultra thin display
  • Some PWM noise
  • Blacks could still be better
  • 3D glasses could be more comfortable
  • CMS doesn't have separate controls for luminance, colour and hue

LG PX990 (50PX990) Review

LG continues to be at the technological forefront and has produced another exceptional display, that pushes the envelope whilst still adhering to industry standards. The 2D performance is exceptional and in the absence of any industry standards, the THX 3D certification represents the closest we currently have to a reference. I was also pleased to see that LG has clearly been listening to feedback and has addressed many of the issues that I raised in my LE8900 review. The PX990 has a few minor issues and LG still hasn't manage to produce the deeper blacks that some of their competitors are capable of but they are still very good and better than any LCD display. Overall the PX990 represents an excellent combination of 2D and 3D performance and coupled with it wonderful build quality and design, as well as its excellent video processing and advanced calibration controls, I am happy to award a Highly Recommended badge

Highly Recommended

Scores

Contrast/Dynamic Range/Black Level

.
.
8

Screen Uniformity

.
.
8

Colour Accuracy

.
9

Greyscale Accuracy

.
9

Video Processing

.
.
8

Picture Quality

.
.
8

3D Picture Quality

.
.
8

Sound Quality

.
.
.
.
6

Smart Features

.
.
8

Build Quality

.
.
.
7

Ease Of Use

.
.
8

Value for Money

.
.
8

Verdict

.
.
8
8
AVForumsSCORE
OUT OF
10

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