Panasonic D25 (TX-L42D25B) Review

Steve Withers takes a look at Panasonic’s latest LCD HDTV with LED edge backlighting and built-in Freeview HD and Freesat HD tuners

TV Review

134

Recommended
Panasonic D25 (TX-L42D25B) Review
SRP: £1,199.00

Introduction

With all the speculation surrounding Panasonic’s attempts to fill the void left in the PDP market by Pioneer’s departure, it can be easy to forget that they also produce an interesting line of LCD displays. The TX-L42D25B is the latest in Panasonic’s line up for 2010 and is not only feature packed but also includes an IPS (In Plane Switching) panel that promises a much improved off-axis performance when compared to contemporary VA (Vertical Alignment) panels. So let’s take a look and see how the TX-L42D25B actually performs when put through AVForums rigorous review process.

Styling and Connections

The look of the TX-L42D25B moves away from the plain black facias that have dominated TV design in recent years and instead offers a lacquered gun metal grey finish to the front coupled with a silver plastic back panel. The bezel itself measures 5cm wide along the sides and top and 6cm wide at the bottom and although it is actually flat there is an interesting effect within the lacquer that gives the impression there is a ridge surrounding the screen. As always design is very much a matter of personal taste and at first I was slightly put off by this optical illusion but over the last week it has rather grown on me. Since the TX-L42D25B has LED edge backlighting it is very thin, measuring a mere 39mm but the downward firing speakers are well hidden and the screen is suitably non-reflective. On the right hand side there are some basic controls such as volume, input choice and a power switch. The overall build quality is very good and the display is mounted on a solid oval stand that is also gun metal grey and swivels.

The remote carries over the colour scheme from the display itself and is made of silver and grey plastic. It is simple, well laid out, comfortable to hold and easy to operate with one hand. It is intuitive to use and includes a number of useful buttons such as the VIEREA CAST, Tools and Link functions as well as Menu, EPG and Aspect Ratio. One feature that I did like was the separate buttons for the TV and AV inputs, which is handy if like me you are constantly switching between the TV and one of the AV inputs.

The TX-L42D25B comes well apportioned as far as connections are concerned with enough for even the most demanding consumer. At the back there are 3 HDMI inputs, one of which is v1.4 and includes an ethernet channel and an audio return channel(ARC). The audio return channel allows the display to send audio when connected to a v1.4 equipped AV Receiver. There are also 2 SCART connections, a LAN socket, component video (Y, Pb,Pr) using 3 RCA phono type connectors, an optical digital audio out, a USB port and an audio in and audio out, both using 2 RCA phono type connectors. Also at the back there is an antennae connection for receiving Freeview and a satellite connection for receiving Freesat.

On the left hand side there is another HDMI input, another USB port, a headphones socket, a SD card slot, a CI (Common Interface) slot and a composite video and audio in using RCA phono type connections.

Its a minor complaint but I still feel that Panasonic would do better to use downward facing inputs to allow consumers to mount their display very close to a wall, especially on these ultra thin displays where wall mounting is quite likely.

Menus and Set Up

As is the case with most TVs these days the set up on the TX-L42D25B was fast and painless. Once you’ve connected the aerial, tuning in Freeview only takes a few minutes and the resulting EPG is large, colourful and easy to read. I do, however, have a couple of complaints; unlike with EPGs on other TVs there is no thumbnail image of the channel you are currently on and, in fact, there isn’t even any audio. In a worrying development there are also adverts on the EPG but hopefully that won’t catch on. Unfortunately the cottage where I live is a listed building which means I can’t put up a satellite dish and I was thus unable to test out the Freesat features on the TX-L42D25B. If you want to use VIERA CAST, which is Panasonic’s Internet TV functionality, you just need to connect the display to your router and then hit the dedicated button on the remote control. You should also be able to use a WiFi dongle connected to one of the USB ports but I didn’t have one available to actually test this.

Like the EPG the main menu system itself is bright, colourful, easy to read and quick to navigate. It offers three choices which are titled Picture, Sound and Set Up. In Set Up there are general controls such as Network Set, Timer, DivX VOD as well as a control called Advanced (ISFccc) that allows you to gain access to the Professional1 and Professional2 picture modes. Hidden away within the Set Up menu is an option called Other Settings and within here you will find three functions that would have made more sense to be included within the Picture menu. There is a control for setting the frame interpolation function which Panasonic calls Intelligent Frame Creation, there is a Resolution Enhancer control and finally a control for setting 16:9 Overscan. This last function is particularly important because only by setting it to off will you get accurate pixel mapping with no scaling and thus benefit from the full resolution of high definition sources.

The Sound menu offers three distinct modes which are Speech, Music and User, with User allowing you to customise the audio set up using an equalizer. There are also more general controls such as Bass, Treble and Balance as well as a setting for the distance between the speakers and the wall. Overall I found the sound of the TX-L42D25B to be quite thin with no sense of depth or envelopment, although this can be improved using the equalizer. I appreciate that most people will wisely use the display in conjunction with an AV receiver but the inherent sound capabilities of the TX-L42D25B are minimal compared to other displays that I have tested.

The Picture menu offers a series of Viewing Modes which range from the eye blistering Dynamic to a preset called True Cinema that appeared to offer reasonable out of the box performance. There are also two isf modes called Professional1 and Professional2 which allow access to additional Advanced Settings and can be locked. The idea is that the isfccc modes provide a professional calibrator with the tools to accurately set the greyscale and colour gamut and then lock these settings so that they can’t be accidentally changed. The reason for two Professional modes is to allow the calibrator to create Day and Night settings, each of which is optimised for watching programmes under different viewing conditions.

At first glance there doesn’t appear to be a control for the display’s backlight, which is unusual, but on further examination it appears that the Contrast control actually controls the backlight. That means the TX-L42D25B doesn’t have a proper Contrast control to adjust the luminance of white, which will make eliminating any clipping very difficult. There is, however, a Brightness control for adjusting the black level, a Colour control and a Sharpness control. The C.A.T.S. (Contrast Automatic Tracking System) function is designed to improve the contrast performance of the TX-L42D25B by adjusting the brightness from scene to scene but this can cause fluctuations in the image and is best left off. Finally there is a P-NR (Noise Reduction) function that is designed to reduce compression artifacts but I found this control to be of no real benefit so I turned it off.
If the Professional1 or Professional2 mode is selected you will have access to the Advance Settings in which there are menus for white balance, Colour Management and gamma. The White Balance menu allows two point calibration of the greyscale, the Colour Management allows adjustments to be made to the Hue and Saturation of the three primaries and the Gamma setting allows a selection of different gamma curves.

Features

As I mentioned in the introduction the TX-L42D25B has plenty of features including a DVB-S tuner for Freesat HD and a DVB-T2 tuner for Freeview HD. In addition the TX-L42D25B also uses an IPS (In Plane Switching) panel, which provides a wider 178° viewing angle which ensures clearer images even when viewed off-axis. Panasonic claim they have further enhanced the panel’s performance with a bright, energy-saving LED backlight. The use of a LED backlight is also intended to improve colour accuracy and contrast performance as well as contribute to the display's slim design.

The TX-L42D25B also includes Panasonic’s Intelligent Scene Controller which is designed to further boost the image quality as well as Intelligent Frame Creation Pro which adds 100Hz frame interpolation and motion focus technology which is designed to enhance resolution. When watching Blu-rays encoded at 24fps the TX-L42D25B has a 24p Playback function that will increase the frame rate to a more appropriate 96Hz which is a multiple of 24. There is also a 24p Smooth Film function that does something similar but includes frame interpolation.

The TX-L42D25B includes VIERA CAST which is Panasonic’s version of internet TV and allows access to selected online content such as YouTube and Eurosport videos and Google’s Picasa Web Albums. It isn’t a web browser but it does provide information such as weather and news and Panasonic plans to add Skype and Twitter in the near future.

The TX-L42D25B includes VIERA Tools and VIERA Image Viewer which allows you to access photos, music or videos either through the SD card slot, the USB port or streaming from your home network via DLNA. In addition you can use a USB port to connect the TX-L42D25B to an outboard HDD but I wasn't able to actually test this function. Finally there is VIERA Link which allows you to control any other VIERA products you might own.

Test Results

For the purposes of this test I used the True Cinema mode which represents Panasonic’s attempt at a calibrated preset. Since Contrast actually seems to control the backlighting I set that to suit the viewing environment but I left the Brightness and Colour settings as they were. I set the Sharpness to zero and for the same reason I turned the Resolution Enhancer off. The C.A.T.S. and P-NR controls were already turned off but I also turned off the Intelligent Frame Creation function as well. The Gamma function was already correctly set to 2.2 and hopefully the actual curve will be close to that number.

As the results show the greyscale performance was quite good for a preset with the majority of the DeltaE (error) measurements being less than 3 which most people probably wouldn’t even notice. The colour temp. was a little below the D65 target between 30IRE and 70IRE and the gamma was a little over the 2.2 curve but at least it was reasonably smooth out to 70IRE. The RGB Tracking shows Red running about 5% over and Blue running about 5% below the target line of 100 but with two point greyscale calibration available I should be able to improve this performance even further.

Much like the greyscale measurements the colour gamut performance shown on the CIE chart was also very good for an out of the box preset. Red is a little oversaturated, Yellow is slightly off and the luminance of Blue and Magenta are also a little high but overall the colour reproduction is very good. The TX-L42D25B includes a Colour Management System so once again I would hope to make improvements with calibration.

Calibrated Results

At this point I’d like to repeat some of the comments that Phil made in his review of the VT20 regarding Panasonic’s menu system. As Phil said they are a nightmare from a calibrator’s point of view because they cover the raster window the meter is aimed at and certain controls have a habit of disappearing after a very short period of time. The easiest solution is to take a look at the measurements, make a few changes and then measure again to see how you have done. This time consuming work-around is hardly ideal and Panasonic really need to redesign their menu system with calibrators in mind. Also, as I’m sure a lot of you know, there aren’t any numbers on the scales which means keeping a record of your settings can get interesting. Apparently this is due to there not being enough memory which I find hard to believe considering my entire music collection can be stored on a device that’s smaller than a fag packet!

After using the White Balance controls to calibrate the greyscale the results were excellent with a DeltaE of less than one for most IRE levels which is imperceptible to the human eye. All three primaries are now smoothly tracking around 100 and the Colour Temperature is now spot on D65 and whilst the gamma is tracking slightly over the 2.2 target it is still a solid performance. The slight peak at around 90IRE is caused by some clipping but without a traditional Contrast control there was no way of improving this. Having said that the clipping is only minor and shouldn’t affect actual viewing material.

Although the Panasonic specifications claim the TX-L42D25B has a 3D Colour Management System (CMS) this isn’t strictly true since it only controls Hue and Saturation but a real 3D CMS would have controls for Hue, Colour and Luminance separately. In addition the CMS only controls the primary colours (Red, Green and Blue) so you don’t have direct control over the secondary colours (Cyan, Magenta and Yellow). However, despite the relatively crude CMS I was able tweak the overall colour performance. After calibration Blue was still a little oversaturated but most of the other colours were reading very accurately and any errors were too small to register when viewing actual material. Overall the colour performance was very good and combined with the excellent greyscale forms the basis of a superb picture.

Panasonic are to be congratulated for including ISFccc controls but perhaps next time they could include 10 point greyscale calibration and a proper 3D CMS with control over all six colours which would bring them in line with many of their competitors.

Video Processing

The performance of the TX-L42D25B in the video processing tests was very good overall, with just one minor flaw. Using both my PAL and NTSC HQV benchmark discs I first checked the SMPTE colour bar test which the TX-L42D25B easily passed, correctly scaling the full 576i and 480i images without any loss of detail or unwanted ringing. The TX-L42D25B 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 TX-L42D25B also resolved all the fine brickwork in the detail tests on both the PAL and NTSC discs.

Sadly the TX-L42D25B did not perform so well in the film detail test and failed to correctly lock on to the image resulting in aliasing in the speedway seats behind the race car (for those of you who are familiar with the HQV test footage). The TX-L42D25B failed all the cadence tests and was unable to correctly detect either 2:2 (PAL - European) or 2:3 (NTSC - USA/Japan) as well as a number of less common formats. The TX-L42D25B did however perform well when displaying film material with scrolling video text, correctly displaying the words without blurring or shredding.

The TX-L42D25B also performed very well in most 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 16:9 mode is correctly set with overscan off) and showed good scaling and filtering performance as well as good resolution enhancement. The TX-L42D25B also had no problems in showing video text overlaid on film based material.

I used my Spears and Munsil test disc to check the headroom performance of the TX-L42D25B from reference white (video level 235) up to peak white (video level 255) and there was clearly clipping above video level 244 which just confirmed what I had suspected during calibration. A display should be able to clearly show detail up to the peak white video level of 255 but it is unlikely you would ever notice clipping above video level 244 in actual viewing material.

Overall this is an excellent set of results and the video processing of the TX-L42D25B is very good with the notable exception of film cadence detection which Panasonic really needs to correct.

Gaming Performance

In the Professional 1 mode the TX-L42D25B measured an input lag of 50ms which is a little slow but better than a lot of other displays I’ve tested. However in Game mode that improved to 30ms which is quite good and should keep all but the most hardened gamer happy.

Energy Consumption

The energy consumption of a LCD display tends to be very consistent and largely depends on the brightness setting of the backlight, rather than being affected by the on-screen images. However dynamic contrast functions like C.A.T.S. will affect energy consumption because these controls vary the backlight and brightness of the display depending on the image. In the Normal mode setting the TX-L42D25B consumed approximately 100w at 0ire, 50ire and 100ire and using the Professional 1 setting it measured about 80w at all three levels; the difference was caused by me disabling the C.A.T.S. function. In standby mode the TX-L42D25B consumed less than 1W of energy, so overall the energy consumption performance was quite good.

Picture Quality

The TX-L42D25B’s highly accurate greyscale, colour gamut and gamma performance coupled with excellent deinterlacing and scaling resulted in a very good picture when watching actual viewing material. Standard definition Freeview broadcasts were quite watchable and any problems tended to stem from the broadcasts themselves rather than the display. With high definition broadcasts the TX-L42D25B deinterlaced the 1080i signal without any problems and the resulting image looked very solid and benefited from the increased resolution. When showing high definition images from Blu-ray discs the 24p Playback function increased the native 24p frame rate to the appropriate 96Hz but you need to ensure that the 24p Smooth Film function is turned off or it will ruin the film-like quality of the presentation. As I mentioned earlier it is also important to ensure that the 16:9 Overscan function is turned off to ensure that full 1080p resolution is being displayed.

The TX-L42D25B also includes Panasonic’s Intelligent Frame Creation Pro which adds 100Hz frame interpolation and motion focus technology which is designed to further enhance the resolution. Whilst I have no problem with doubling the frame rate from 50 to 100 or using 24p Playback to increase the frame rate of a Blu-ray disc from 24 to 96 I am not a fan of any form of frame interpolation. Even though I can sometimes see slight improvements in video based material, I don’t find the improvements really warrant all the fuss that manufacturers’ marketing departments make and, ultimately, these systems make little or no difference to the motion limitations inherent in LCD technology. Worse than that, when used in conjunction with film based material the interpolation has a detrimental effect on the image, which loses all sense of being film-like and begins to look like video. Personally I rarely use any frame interpolation functions and, to be honest, I almost always just leave them off.

One of the major selling points of the TX-L42D25 is its use of an IPS panel and the improvements of this technology were evident when I tested the display’s off-axis performance. When viewed from the sides the image did not suffer from the usual loss of contrast and colour desaturation that plagues VA panels. There was a slight loss of contrast when viewed at extreme angles but the colour reproduction remained solid and the TX-L42D25B clearly showed superior off-axis performance. In their marketing literature Panasonic claim that their use of LED backlighting produces better black levels when compared to displays that use normal CCFL backlighting. To be honest I can’t say that I’ve ever really noticed a difference but the use of edge backlighting certainly has a detrimental effect on the uniformity of the backlighting. Whilst better than a lot of other displays with edge backlighting there was some slight clouding, especially at the edges themselves. I felt the black levels on the TX-L42D25B could also have been better and I suspect this is a result of both the IPS panel and the edge backlighting. I guess that is just the price you pay for an ultra thin display and improved off-axis performance. Sadly no display technology is perfect and there are always compromises.

Verdict

7
AVForumsSCORE
OUT OF
10

The Good

  • True Cinema provides a reasonably accurate preset
  • Excellent Greyscale performance after calibration
  • Very good Colour accuracy after calibration
  • Deinterlacing and scaling capabilities are very good
  • IPS panel provides very good off-axis performance
  • Full ISFccc Calibration controls
  • Freeview HD and Freesat HD built in
  • VIERA CAST Internet TV features
  • Extensive networking and connectivity options
  • Reasonably small input lag in Game mode

The Bad

  • Black levels could be better
  • Backlighting uniformity could be better
  • Still lacks film cadence detection
  • Menu system needs to be redesigned for easier calibration
  • Downward facing HDMI inputs would make more sense on an ultra thin display

Panasonic D25 (TX-L42D25B) Review

I was very impressed with the TX-L42D25B, its accurate greyscale and colour gamut combined with excellent deinterlacing and scaling resulted in a very pleasing image. In addition, due to the use of an IPS panel, the off-axis performance was much better than other displays that use different panels.

That’s not to say it’s perfect. Despite the improved off-axis viewing there was a definite trade off in black level, and whilst the LED edge backlighting might mean it’s less than 4cm deep, the screen uniformity could be better, especially at the edges. However, no display technology is flawless and my only other complaints are very minor ones relating to cadence detection and the menu system.

Overall the TX-L42D25B is a great LCD HDTV with an excellent greyscale, accurate colours, good quality deinterlacing and a very pleasing picture. If that were all I’d have no reservation in recommending the TX-L42D25B, but, in addition, it also comes packed with features like internet functionality, Freeview HD and Freesat HD. So if you are looking for a slim display with a great picture you should definitely consider the TX-L42D25B.

Recommended

Scores

Sound Quality

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5

Smart Features

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.
.
7

Ease Of Use

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.
.
.
6

Build Quality

.
.
.
7

Value for Money

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.
.
.
6

Verdict

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.
.
7

Picture Quality

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.
.
7

Video Processing

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.
8

Greyscale Accuracy

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8

Colour Accuracy

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8

Contrast/Dynamic Range/Black Level

.
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7

Screen Uniformity

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7
7
AVForumsSCORE
OUT OF
10

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