Panasonic ST50 (TX-P55ST50) 3D Plasma TV Review

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We've seen the 50 and the 65, now Mark checks out Panasonic's ST50 inbetweener

by Mark Hodgkinson Aug 29, 2012 at 12:00 AM

  • TV review


    Highly Recommended
    Panasonic ST50 (TX-P55ST50) 3D Plasma TV Review
    SRP: £1,999.00


    The model we have for review is the Panasonic P55ST50B 55 inch Full HD 3D Plasma TV with a Freeview HD tuner and full UK specifications. Also available is the Panasonic P42ST50B 42 inch Full HD 3D Plasma TV, the Panasonic P50ST50B 50 inch Full HD 3D Plasma TV and the Panasonic P65ST50B 65 inch Full HD 3D Plasma TV which have not been reviewed here but should offer the same features and a similar performance. Since we’ve already looked at the 50ST50 and the monster 65inch version, we thought we’d best check out the ‘in-betweeny’ Panasonic TX-P55ST50. The NeoPlasma G15 panels have been winning almost universal praise since their release in April 2012 but there have been a few concerns about screen uniformity with TVs out in the wilds and what better way for us to investigate than with a sample sourced from a retailer? Which is precisely what we’ve been able to do and since we’ve seen some extremely serious competition, for the ST50, in the shape of Samsung’s fabulous 60ES6500 plasma, hopefully an interesting back to back comparison.

    Styling, Connections and Menus

    Having had the Panasonic 55ST50 and Samsung 60E6500 back to back on our test bench, the remarkable similarities are self-evident. Panasonic term it the ‘metal and glass design’ which is certainly accurate - if not inspired - but what Panasonic term the ‘Crystal Strip’ is clearly a wholesale knock off of Samsung’s own ‘Cystal’ designs. Clearly both manufacturers are stretching the truth, somewhat, as both strips are just transparent plastic. We like the gun metal colouring of the ST50’s bezel which is matched to the – non-swivelling – base stand.

    The growing trend of cutting back on HDMI inputs continues with Panasonic 55ST50 having only three, each being side facing and just 9.5cm from the furthermost point of the ‘crystal’ strip. Also sideways facing there are two USB sockets, with USB 1 designated for HDD recording, a headphone socket, a SD card slot and a Common Interface (CI) slot. Running along the bottom, and downward facing, are the legacy composite and component video connections that use breakout adaptors, along with the aerial input, an optical digital out and a LAN socket.

    Duplicated from almost every other 2012 Panasonic is the new, and much shinier, remote control which is conveniently backlit as well as being sensibly designed with most of the ‘important’ buttons ergonomically placed for one-handed operation. It does show up greasy fingerprints more readily than the outgoing design so make the kids wear cotton gloves around the house. Not in the box but necessary for testing the 3D aspect are a pair of Panasonic's USB rechargeable TY-ER3D4MU glasses. As we’ve said previously we’re big fans of the new specs with them weighing in at just 26g and being very neutral in tint.

    The Menu has five primary sub-menus - Picture, Sound, Network, Timer and Setup but we’re just going to give you a rundown of the picture options here, having covered them in great detail in earlier reviews.

    The Picture menu contains a choice of Viewing Modes including Dynamic, Normal, Cinema, True Cinema and Game. This sub-menu also includes all the usual front panel controls – Contrast, Brightness, Colour and Sharpness. There’s also the (unnecessary) Vivid Colour control and C.A.T.S. (Contrast Automatic Tracking System) option which is designed to adjust picture contrast according to ambient light in the room. Finally there is a P-NR (Noise Reduction) function that is designed to reduce compression artefacts and can be useful if you insist on watching the likes of ropey YouTube content on the big screen.

    Also in the Picture Menu there are the Advanced Settings where you will find the 16:9 Overscan function. It is important to ensure that the 16:9 Overscan function is set to Off and the Aspect Ratio is set to 16:9 for high quality HD sources. There is also a control for Intelligent Frame Creation or 24p Smooth Film (when the content is encoded at 24p) which can be set to Off/Min/Mid/Max. Then there is the Clear Cinema mode for film cadence detection and the Resolution Enhancer control which is essentially another sharpness control and is best left off. Finally the Side Panel control increases or decreases the brightness of the side panels, whilst the Pixel Orbiter and Scrolling Bar functions are designed to reduce image retention.


    Since the feature set of a modern day TV is so rich in content, we thought we’d take some steps to reflect the shifting sands by means of dedicated reviews for the various manufacturer’s Smart platforms. Fortunately, for this reviewer, I was beaten to the task by Steve Withers who gives chapter, verse and a whole lot more in his report here. If you’re only interested in a summary of that review, Steve concluded, ”Overall Panasonic's Smart VIERA platform is excellent and whilst some manufacturers offer a slicker interface or more features, Smart VIERA effectively covers all the bases. The VIERA Remote app is superb and in terms of interaction between your TV and your smartphone or tablet, Panasonic is ahead of the game."

    Test Results

    Out-of-the-Box Measurements

    Whilst it’s not quite what we could live with, the out-of-the-box Normal viewing mode with a Normal Colour Temp was far more accurate than every other factory mode we’ve published the results on, so far, with only a comparatively small excess of blue energy. Gamma tracking was far from ideal, however, which did give the picture a washed out look, although, to be fair, it wouldn’t have been a bad choice for a sun soaked room – so, around 7 days a year, in these parts. The colour gamut was predictably over-saturated and overly bright but hue errors were mostly respectable, with the exception of the orangey reds.

    Basic Set-Up Results

    A quick switch in to True Cinema mode and setting Brightness and Contrast with the appropriate patterns brought us closer still to our targets with Delta Errors below 5 for greyscale in all but the brightest portions and a much closer representation of the Rec.709 gamut standard. Red is still the concern as far as the colour reproduction goes and we may be hard pressed to get it to fully saturate.

    Calibrated Results

    These are by no means the flattest charts we’ve seen from a Panasonic plasma in 2012 but, all the same, highly respectable with errors all below 2 throughout the scale. Gamma tracking is certainly improved by switching to the 2.4 pre-set, from the 2.2 default of True Cinema, but with no dedicated multi-point control or 10 point White Balance controls we were unable to get it totally flat. We were left with a choice of having a large spike – upwards – between 70 and 100% stimulus and maximising light output to around 120cd/m2 or taming the spike and dropping light output to nearer 100cd/m2. On balance, we found the bigger spike could give a waxy look to skin tones and opted for the slightly dimmer picture. That kind of output is fine for a lowly lit room but those in brighter viewing environments could use a little more.

    Our fears of being able to fully saturate red proved founded but we were able to balance the error by minimising the orange tint and obtaining reference luminance. As the multi-saturation point graph demonstrates below, red doesn’t saturate fully through various ‘intensities’ which makes skin tones just a little washed out, compared to a more reference display but most would be hard pressed to notice. Elsewhere the excellent results reflected in the CIE above, where only 100% saturation is depicted, carries over in to the performance at multiple points. Hue errors are minimal with both and the ST50 is capable of delivering extremely believable colours.

    Contrast and Black Level

    This is definitely the area where Panasonic have ruled the roost most comfortably in 2012. The results here were predictably first class, if ever-so-slightly less impressive than those we measured with the 65inch ST50. Full screen black clocked in at 0.013 cd/m2 with peak white reaching 103 cd/m2. As we said in the calibration section above, we could have had a higher output but at the expense of inferior picture quality. Still with an On/Off Contrast Ratio of just under 8000:1, it’s not a bad result. Intra-frame contrast, i.e. the relative difference between dark and light elements of the picture was also very impressive, with the 55ST50 hitting an average black level of 0.015cd/m2 against an average peak light output just under 77cd/m2, giving an ANSI contrast of 5261:1. Impressive stuff!

    Video Processing

    The performance of the P55ST50B in the video processing tests was excellent overall. Using both the PAL and NTSC HQV benchmark discs the detail and resolution test was reproduced correctly, with the P50ST50B scaling the full 576i image without any loss of detail or unwanted ringing. The ST50B also scored very highly in the jaggies tests on both discs as well as performing very well on the diagonal interpolation test, with two of the three moving bars appearing smooth and only the bottom most extreme bar showing very slight jaggies. The 55ST50 also had no problems in resolving all the fine brickwork in the detail tests as well as correctly displaying the waving flag footage.
    The Panasonic TX-P55ST50 managed to correctly the 2:2 (PAL - European) film cadence, as long as the Clear Cinema function is turned on. The P55ST50B also performed well when displaying film material mixed with scrolling video text and correctly displayed the words without blurring or shredding. The ST50 performed extremely well in most of the tests on the HQV Blu-ray using high definition content and with the player set to 1080i the display correctly deinterlaced and displayed both the video and film resolution tests and showed very good scaling and filtering performance as well as excellent resolution enhancement.
    When watching film based content you should always have the IFC function off, unless you want it to look like video. For the same reason you need to ensure that the 24p Smooth Film function is also turned off when watching 24p material. We used the Spears and Munsil disc to check the headroom performance of the P50ST50B which was very good, correctly reproducing from reference white (video level 235) up to peak white (video level 255) and showing picture information down to reference black (video level 17).

    Gaming Performance

    As with every 2012 Panasonic plasma display we’ve tested with our new dedicated device, input lag is higher than we’ve come to expect from them but most won't find a latency in the 47 millisecond range too debilitating. We’d like to see that number come down in 2013 and serious gamers are advised to try before you buy.

    Energy Consumption

    • Standby: 0.0W
    The following measurements were taken with a full screen 50% white pattern:
    • Out of the Box – Standard Mode: 203W
    • Calibrated – True Cinema Mode: 149W
    • 3D – True Cinema Mode: 299W

    Picture Quality – 2D

    There’s not much left to say about the qualities inherent of the Panasonic G15 plasma’s but, for the benefit of those unaware, they are offering pictures of an extremely high calibre indeed. Boasting superb black levels and contrast performance, outstanding post calibration accuracy and some truly excellent video processing, the 55ST50 is no exception to what has gone before and is truly a joy to watch, almost all of the time. The same niggles are also present in the shape of some dynamic false contouring (DFC) and panning issues with 50Hz content which, looking at further, seems almost isolated to instances where the vector processing is being pushed to its limits, i.e. when objects are moving diagonally across the screen; which can cause edge-break up and multiplication almost anywhere on screen but we’d hardly call the 50Hz issues distracting this year. In most instances, using IFC at minimum should help clean it up a little. The DFC is definitely the biggest bugbear we have with the 2012 Panasonic plasma’s and, unfortunately, the only way to mitigate it is by engaging IFC at Max which gives images an awful ‘speed up/slow down’ cheap video camera effect and converts 50hz content to a 60Hz refresh where the subfield driving is more optimally tuned. We’d like to say calibration could help it but that’s not the case at all, simply by viewing in the most accurate (True Cinema) mode is about the most you can do but, that said, instances are fleeting and rare.

    The ‘big issue’ for the Panasonic plasma’s on the forums this year has come in the form of a uniformity issue. Last year we had the ‘green blobs’ which in 2012 has been replaced by vertical banding complaints; where owners can see thin vertical strips down the panel that aren’t illuminated to the same degree as the rest of the screen. We first spotted it with the UT50, which had one faint strip just in from the right hand side that was very occasionally visible on certain content. The retail sourced Panasonic 55ST50B, under scrutiny here, was almost identical to the UT50 with the same thin, feint strip just in from the right hand side but it also had another either side. Would we call it an issue? Perhaps but in this particular manifestation, one of only very minor proportions as it was so very rarely visible with real world content. That said, we have seen some instances that look a lot worse, at least in photographs, so we can understand how those affected would feel more greatly aggrieved.

    In terms of a comparison to the Samsung plasma’s, there’s so little in it, in the larger screen sizes, that it will come down to a touch of personal preference and which niggles you can most easily tolerate/not live with. For the Panasonic 50Hz and DFC problems you can swap brightness pops and some floating blacks in the Samsung’s but, either way, you’ll be choosing the best of the bunch in 2012.

    Picture Quality – 3D

    The 3D images produced by the P55ST50B were excellent, with well-defined depth and a sense of solidity to the objects on screen. Whether the 3D content was provided by a frame sequential Blu-ray, a side-by-side TV broadcast or a 3D game, the 55ST50 was able to detect and correctly display the 3D images. The P50ST50B includes a 2D to 3D conversion function but whilst this worked to a degree, it remains nothing more than a gimmick feature that is best avoided. Overall however, when it comes to native 3D content, the P55ST50 is another winner from Panasonic that can deliver a wonderfully engaging 3D experience.


    OUT OF

    The Good

    • Very impressive black levels
    • Superb contrast ratio and dynamic range
    • Excellent greyscale when calibrated
    • Close to reference colour gamut when calibrated
    • Added calibration controls
    • Reference level 3D playback
    • Minimal crosstalk
    • Excellent video processing
    • Built-in WiFi and Freeview HD
    • VIERA Connect is impressive
    • Well designed menus and remote control

    The Bad

    • Dynamic False Contouring
    • 50Hz panning issues
    • Only 3 HDMI ports
    • Input lag could be lower
    • Mild uniformity problem
    You own this Total 0
    You want this Total 0
    You had this Total 0

    Panasonic ST50 (TX-P55ST50) 3D Plasma TV Review

    Why change a winning formula when it comes to design or alternatively, why change a competitor's winning formula when it comes to design? Which is precisely what Panasonic seem to have done with the ST50’s Samsungesque appearance. At least the remote control is trademark Panasonic, which is no bad thing, but we would have liked to see 4 HDMI ports, rather than the slightly stingy 3 provided. We like the simplicity of the Panasonic menu systems - which seem to manage the trick of putting everything where you would expect it to be – and Panasonic’s 2012 Smart offerings continue to gather momentum in terms of sheer quantity.

    The True Cinema picture mode continues to be the best bet for ST50 owners seeking the most accurate images and the TX-P55ST50, reviewed here, made a reasonable fist at hitting the standards. Post calibration we were very close indeed to hitting reference greyscale and colour reproduction which, when backed up by the excellent contrast and black levels, helped to deliver pictures of an extremely high quality. The only real blights being some instances of dynamic false contouring and edge break up, particularly with content delivered at 50Hz. We did have some minor uniformity issues with the review sample, in the form of three very feint bands to the right hand side but they were so rarely visible, ‘issue’ is perhaps too strong a word. Along with the Samsung plasma’s, the G15 Panasonic’s are delivering some absolutely wonderful pictures in 2012 and we’re fortunate to have such great options.

    The 3D images produced by the P55ST50B were excellent, with well-defined depth and a sense of solidity to the objects on screen; the P55ST50 is another winner from Panasonic that can deliver a wonderfully engaging 3D experience. As with every 2012 Panasonic plasma display we’ve tested with our new dedicated device, input lag is higher than we’ve come to expect from them but most won’t find a latency in the 47 millisecond range too debilitating

    The TX-P55ST50B is another sure-fire winner from the Panasonic plasma stable that manages to combine class leading contrast performance with an excellent feature-set to produce a display worthy of an enthusiast’s attention. The fact they’ve managed to do that at an extremely attractive price-point only further cements the bestowing of an AVForums Highly Recommended Award.

    Suggested retail price when reviewed: £1,999.00

    The Rundown

    Contrast/Dynamic Range/Black Level


    Screen Uniformity


    Colour Accuracy


    Greyscale Accuracy


    Video Processing


    Picture Quality


    3D Picture Quality


    Sound Quality


    Smart Features


    Build Quality


    Ease Of Use


    Value for Money




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