LG PK350 (50PK350) Review

With a recommended retail price of £595 and offers even cheaper than that from some online retailers you could be forgiven for thinking that this would be reflected in the PK350’s build quality. However you’d be wrong as the PK350 is surprisingly solid with a gloss black bezel and black metal chassis. The Razor Frame bezel measures an impressively sleek 3.5cm at the top and sides and 7cm at the bottom and overall the display is surprisingly thin for a 50” plasma with a depth of just over 5cm. This level of build quality also extends to the stand which is equally solid and allows you to swivel the display.

The only real indication that this is a budget display is when you take a look at the connections. At the back there is only one HDMI input, although there is a second one at the side but of course this is also irrelevant if you are using an A/V receiver with HDMI switching. If you’re not then this could prove a bit limited, especially as most homes these days might have more than two HDMI devices connected to a display. In addition to the HDMI inputs there is also an antennae socket at the back, along with two SCART sockets, component input, a VGA input, a digital optical out and a RS232 interface.

At the side there is the standard Common Interface card slot, a USB port and a composite video and left and right analogue audio RCA connectors.

The PK350 uses the same menu system as all the other LG displays but this is a good thing as I think that LG’s menu system is one of the best available. It is sensibly laid out and uses large colourful icons that are easy to read. The menu is simple to navigate and very responsive which makes a nice change from some manufacturers over complicated and slow menu systems.

The main menu page gives you a series of eight options each represented by an appropriate icon. Aside from the Set Up, Picture and Audio options which I’ll come back to there is also the Time option which relates to setting the time as well as the timer and sleep mode functions and the Lock option which controls the parental lock. In addition there is Option which offers a series of generic controls for functions such as language, the Input option which obviously allows the user to change between inputs and label them and the USB option that allows the user to watch content via the USB input.

Within the Picture menu there is an option for choosing the Aspect Ratio, 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 number of options but Movie mode would be the most appropriate preset to choose. 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 then the calibrator can create one mode for viewing material in the daytime and one for viewing material at night. Also within the Picture Mode are the standard controls such as Contrast, Brightness, Vertical and Horizontal Sharpness, Colour and Tint.

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 are Noise Reduction controls for both analogue and digital signals but I found they didn’t really improve the picture and were best left off. The Black Level function should be left on Low and the Real Cinema function controls the deinterlacing of film based material and should always be left On. The Colour Gamut offers a choice of Standard and Wide with Standard being the best to choose. 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, here I found Warm to be the best choice, and Gamma for which I selected 2.2. The PK350 has both 2 point and 21 point White Balance control, I selected the 21 point option which should allow me to very accurately calibrate the Greyscale and Colour Temperature.

Finally there is a Colour Management System that allows you to accurately calibrate the Colour Gamut. In the CMS that LG has built into the PK350 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 both the saturation and luminance and Tint which sets the hue.

As you would expect with a display in this price range the number of features is a bit limited but if I’m being honest I don’t think that necessarily makes a great difference. First of all the Freeview tuner doesn’t include high definition so if you want to watch the BBC, ITV and Channel 4 HD channels you’ll need to use an outboard decoder but then you’d probably want one anyway so that you can also record programmes. Secondly the PK350 doesn’t include LG’s NetCast internet TV feature but personally I don’t see that as a much of an issue since I hardly ever use this kind of feature. Thirdly the PK350 lacks the ability to stream DNLA compliant content over a network but you can view content via the USB connection. Finally whilst the the PK350 does have 600Hz motion technology it lacks the THX mode and the TruBlack Filter that you find on LG’s more expensive plasmas.

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 use test screens and tells the user what they should be looking for in order to correctly calibrate the Brightness, Contrast, 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 signal generators and calibration discs.

I selected the Movie preset and performed a basic calibration on the PK350 by setting the brightness and contrast correctly, selecting the best Gamma and Colour Temperature settings, ensuring that any unnecessary video processing was turned off and that the Sharpness controls were set correctly so that they weren’t adding ringing or making the image softer.

The out of the box Greyscale performance was very good for a pre-calibrated setting with a DeltaE of less than 3 from 20 to 100 IRE which represents an error that should be un-noticeable to the human eye. As you can see from the graph the main errors are between 20 and 50 IRE with Blue tracking about 10% below the target and Red tracking about 10% above the target. Whilst the Gamma was also tracking above the target of 2.2 it was actually quite good and overall this is a very good performance and the access to a 21 point White Balance control should allow for even greater accuracy.

The out of the box Colour Gamut performance was also quite good with overall DeltaEs of less than 5 for all the colours which is very good. The Luminance errors were all very low which is good because this is the error that is most noticeable and the same applied to the Hue measurements with the exception of Magenta. The Colour measurement showed that the image was a little saturated, especially in Green and Red but overall this is a very good result for a pre-calibrated setting. The addition of a Colour Management System should hopefully allow for an even more accurate performance.

Unfortunately when I tried to calibrate the PK350 using the 21 point White Balance I discovered a bug in the software. At first I was unable to affect he Greyscale measurements no matter how much I changed the settings but after a discussion with Phil I found out that moving the Contrast control down seemed to fix this problem. However even after setting all the separate points at 5 IRE intervals I found that despite reading correctly on the meter when I looked at step test pattern there was obvious discolouration. So it would seem that LG need to bring out a software fix to ensure that the 21 point White Balance controls are working properly because when they do they will offer an unprecedented degree of control.

Despite this problem I was able to use the two point White Balance control just as effectively and the resulting performance was superb with all the errors below 3 and most below 1. The Gamma was now tracking between 2.0 and 2.2 which is more appropriate for a display in a room with some ambient light. Overall this is a reference performance in terms of Greyscale accuracy and other manufacturers could really learn from LG’s example.

Although the Colour Management System doesn’t have separate controls for Luminance, Saturation and Hue the controls that are available do allow for a reasonable amount of flexibility. I was able to get the overall DeltaEs down to less than 3 for all the colours which is excellent and below the threshold at which the human can’t distinguish these errors. The error numbers for Luminance and Hue were excellent but the image was still slightly over-saturated in Blue, Green and Cyan (which makes sense since Cyan is a combination of Blue and Green). Overall this is a reference performance in terms of accurately reproducing Rec709 and once again LG are to be congratulated.

Video Processing

The performance of the PK350 in the video processing tests was very good. Using both my PAL and NTSC HQV benchmark discs I first checked the SMPTE colour bar test which the PK350 easily passed, correctly scaling the full 576i and 480i images without any loss of detail or unwanted ringing. The PK350 also performed very well when it came to video deinterlacing with jaggies only appearing when the line was at a very extreme angle. In the second test the motion adaptive deinterlacing was also excellent with slight jaggies only appearing on the bottom line.

The PK350 also performed well in the film detail test and correctly locked on to the image resulting in no aliasing in the speedway seats in the familiar race car footage. In the cadence tests the PK350 correctly detected both the 2:3 (NTSC - USA/Japan) format and the 2:2 (PAL - European) format. Finally the PK350 performed equally as well when handling film material with scrolling video text, correctly displaying the words without any blurring or shredding.

The PK350 performed very well in 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 PK350 also had no problems in showing video text overlaid on film based material and also handled 24p content without any problems. In addition to displaying 24p material, the PK350 also had no problems with 50Hz or 60Hz material.

I used my Spears and Munsil test disc to check the headroom performance of the PK350 from reference white (video level 235) up to peak white (video level 255) and there were no signs of clipping, in addition the PK350 also showed detail down to video level 17 with black below that. The PK350 also performed well on the other tests on this disc including tests for dynamic range, sharpness, contrast, greyscale and image cropping.

Overall the video processing performance of the PK350 was excellent and better than many of its more expensive competitors.

Gaming Performance

The input lag time was about 50ms which is surprisingly high, especially for a plasma. I have reviewed LCD displays with input lags from 10 to 80ms but the majority of plasmas that I have tested have very low lag times so I'm not entirely sure why the current crop of LG plasmas have such high input lags. Having said that I wasn't aware of the input lag during actual game play but it might be a little slow for hardened gamers.

Energy Consumption

Like all plasma displays the PK350 uses a self illuminating technology so the power consumption varies with the content shown on screen. Therefore high contrast white background material will use more power to create an image whilst darker scenes will use less. The highest measured figure with normal viewing content was 300 watts, the lowest was 180 watts and the average was 220 watts. The consumption figures at 0, 50 and 100 IRE rasters in the calibrated picture mode were 150 watts, 210 watts and 350 watts. The PK350 doesn’t have the most efficient energy consumption, even for a plasma but it’s average consumption number is quite good.

The overall picture quality of the PK350 was excellent and very impressive for a display in this price range. The accurate Greyscale and Colour Gamut resulted in a superb base from which to build the rest of the image and the excellent video processing resulted in fantastic images from both standard and high definition sources.

Blu-rays of course looked fantastic with the accurate Greyscale and natural colours really showing through and the 1080p image resolving plenty of fine detail. When watching 50Hz and 60 Hz material the pictures were free of any processing artefacts and there were also no issues when watching 24p content with the images free of any judder. As you'd expect from a plasma its handling of motion was excellent and this really showed through not only on Blu-rays but also on video games. The performance was equally impressive when displaying a 1080i Freeview HD image provided by an outboard tuner.

The internal Freeview decoder did a good job and the resulting picture was relatively free of compression artefacts on the channels that use a reasonable bandwidth. Thanks to the excellent scaling and deinterlacing in the PK350 standard definition images looked very good and were thankfully free of artefacts; DVDs in particular looked very impressive.

I didn't experience any problems with image flicker and the instances of image retention were quite rare, I certainly wasn't aware of any image retention when watching normal viewing content. Previous LG displays had suffered from unnecessary edge enhancement that couldn't be defeated but there appeared to be no such issues with the PK350.

This isn’t to say that the PK350’s image was perfect because it still suffered from a couple of minor issues. First there were some reflections off the screen but this seems to be an issue with all displays and it shouldn’t be a problem a long as you’re careful about ambient light. Secondly there was a bit of PWM noise but you can expect that from every plasma to some degree or another and it didn't cause any loss of sharpness nor was it noticeable at a sensible viewing distance.

Finally the PK350 suffered from LG’s usual underwhelming blacks which has always been their weakest link. The addition of the TruBlack Filter on their more expensive displays has certainly helped in this area but since the PK350 doesn’t have the TruBlack Filter its blacks can’t compare to many other plasmas that I've seen. Having said that I'm not expecting a Kuro at this price point and the blacks on the PK350 are still better than almost all LCD displays.

Overall I think that the picture quality on the PK350 and the resulting image was pleasing and natural no matter what the source.