LG 42PG6000 Review

The LG 42PG6000 plasma television should make the shortlist of anyone looking to acquire a flat screen HDTV for less than £700. Boasting a “frameless” design which scooped up the “Best Of Innovation” award at CES (Consumer Electronic Show) 2008 in Las Vegas, 4 HDMI 1.3 inputs, and a quoted contrast ratio of 30,000:1, the PG6000 plasma series may have been partly responsible for LG outselling Matsushita (parent company of Panasonic) in terms of global plasma volume shipped for the first time since the third quarter of 2006.

A non-true-HD native screen resolution of 1024×768 is probably the only slight chink in the armour of the LG 42PG6000 when you look at the specification sheet, but hey, you can’t expect the world at this bargain price.

We have completed a review of the LG 42PG6000, which contains a few comments comparing its performance against the Panasonic PX80, its main competitor in terms of specification and pricing. The LG 42PG6000 holds the edge in colour accuracy, overall video processing (especially in standard-def) and aesthetics, while the Panasonic TH42PX80 is capable of deeper blacks and native 1080p/24 playback free of telecine judder, and is more resistant to image retention.

At the end of the day, both of these HDTVs are fine choices for buyers looking to spend no more than £700 on a plasma TV. The only reason we gave the PX80 a higher rating is because some of its chief deficiencies could potentially be remedied by “outsourcing” (e.g. scaler, dedicated video processor); whereas most of the LG 42PG6000′s shortcomings are “fixed” (e.g. lighter black level, non-native 24fps playback, proneness to image retention).

Panasonic TX 37LZD85 Review

In what has turned out to be our most productive month yet this year, we have reviewed the Panasonic TX37LZD85 LCD HDTV which boasts a full high definition native screen resolution of 1920 x 1080, and 100Hz Motion Picture Pro MCFI (motion-compensated frame interpolation) technology.

You may be surprised by our not-entirely-positive review, especially when the Panasonic TX-37LZD85 has received 5-star awards and rave reviews almost everywhere else. The reason is simple.

Here at HDTVTest we review flat screen televisions using objective tests rather than in a subjective manner. Instead of just saying “the blacks look deep”, we measure the actual calibrated black level. Instead of just writing “rich natural colours”, we plot colour points on a CIE diagram. Instead of just noting down that there’s some motion blur, we record the motion resolution. Instead of just mentioning how good SD content looks, we run a battery of tests (including but not limited to scaling, video mode and film mode deinterlacing) to quantify the video processing capabilities of each HDTV we review. You get the idea.

However, when performing objective tests there should be a standard/ yardstick by which to judge the parameter we’re measuring. In the field of HDTVs, SMPTE (Society Of Motion Picture and Television Engineers) continues to set the industry standard, and so a number of SMPTE specifications form the basis of our calibration and picture quality assessment.

What we’re essentially saying is that the Panasonic TX-37LZD85 doesn’t quite measure up to some of our review criteria which demands an accurate image true to source without undesirable processing. To many the picture looks good; to us it may appear artificially enhanced.

And we’re honest about it, without any sugar coating. Perhaps that’s why rogue review sites can get a link from manufacturers whereas HDTVTest will never get a mention…

Sony KDL40W4000U Review

Thanks to every reader who kindly contributed to the fundraising campaign which made it possible for us to acquire this LCD television for testing purposes, our Sony KDL40W4000 review is now complete.

The specific model we reviewed was the Sony KDL40W4000U, where the ending alphabet “U” denotes the UK 3-pin-plug version. Europeans get the Sony KDL40W4000E which sports the added advantage of an integrated AVC HD tuner. Is it just us or does anyone else feel that the Brits always get short-changed?

Some things the Sony KDL40W4000U did better than the W3000; some things it did worse. While it’s difficult to call it a massive improvement over its predecessor, the Sony KDL40W4000U still delivers exceptional picture quality due in no small part to excellent blacks and accurate primary colours.

Panasonic TH42PZ80 / TH42PZ80B Review

Panasonic TH42PZ80 is the third plasma HDTV from the world’s largest plasma flat screen manufacturer we’ve reviewed in as many months. The Panasonic TH42PZ80 offers true high definition 1920 x 1080 screen resolution over the HD-ready PX80 range, but lacks the “Intelligent Frame Creation” and “24p Real Cinema” motion compensated frame interpolation (MCFI) technologies found on the TH42PZ85B. Let’s see if this plasma television can help Panasonic complete a hat trick of “Highly Recommended” awards from HDTVTest in first-half of 2008.

Note: The specific model we tested was the Panasonic TH42PZ80B (which denotes the 3-pin-plug British version), but the terms TH42PZ80 and TH42PZ80B will be used interchangeably throughout this review.

Design

While sporting the same glossy black bezel with inscriptions of “Viera” on the top left and “Panasonic” at the bottom centre, what distinguishes the Panasonic TH42PZ80 from the PX80 and PZ85 series is a silver protrusion resembling an upper lip that spans the entire width of the frame at the bottom of the panel. Sandwiched between this and the bottom border of the bezel are a pair of TV speakers, an LED indicator and some infrared/ light sensors. On the protrusion itself you can find a central flap that flips up to reveal some control buttons and connection ports (including a HDMI input and an SD card slot).

Otherwise, the Panasonic TH42PZ80 shares similar design characteristics to the TH42PZ85: a wedge-shaped pedestal stand; some cooling fans (though 1 less than the PZ85) and a pair of recessed handgrips at the back of the panel; and high overall build quality.

Connections

Unfortunately one of the three HDMI inputs is located at the front (under the central flap) of the Panasonic TH42PZ80, which may well mean the inevitable presence of an unsightly cable should you need to use all three HDMI ports.

Rear: 2 x HDMI, VGA, component, 2 x Scarts, CI slot, aerial, audio outs

Front: control buttons, headphone, Svideo, composite, HDMI, SD card slot

Operation

Except for the understandable omission of [Intelligent Frame Creation] in the user menu, the on-screen menu, EPG and infrared remote control that comes with the Panasonic TH42PZ80 plasma television are essentially the same as those found on the TH42PZ85B. Viewers with sensitive ears may pick up the slight whir of the cooling fans, or power/brightness-related plasma buzzing, but assuming you sit more than 6 feet away from the screen, these background noise should be adequately drowned by normal TV volume.

Calibration

Greyscale

Although post-calibration settings may vary from unit to unit, our Panasonic TH42PZ80 review sample needed no further adjustment (not that there were many picture controls available inside the user menu to start with) other than changing [Viewing Mode] to “Cinema” and [Colour Balance] to “Warm” to achieve the following greyscale results:

[Colour Balance] “Warm” CCT	[Colour Balance] “Warm” RGB tracking

Both red and blue values were higher than ideal, but they sort of neutralised each other to give a 6500k-ish correlated colour temperature (CCT). Make no mistake though, delta errors (dEs) remained around 8. Most people probably can’t see the difference in real-life viewing, but if you wish to reduce the dEs below the 4 threshold, you’ll have to venture into the service menu (and risk voiding your warranty) to adjust the RGB cuts and gains.

Gamma

Following our recent “What Is Gamma” article, we thought it’d be enlightening to include the gamma graphs of the Panasonic TH42PZ80:

Luminance vs input signal	Gamma vs input signal

Overall gamma on the Panasonic TH42PZ80 after calibration was just a touch below 2.0, which means that the picture would exhibit brighter (perhaps too bright) shadow detail and slightly reduced punchiness/ “pop” compared to the 2.2 ideal. We would have appreciated the inclusion of a gamma control in the user menu to deal with this issue, but to be fair a gamma of 2.0 will probably irk only the staunchest of videophiles.

Colour

Panasonic TH42PZ80 CIE chart with reference to HD Rec. 709

No surprises here… the colour gamut of the Panasonic TH42PZ80 was almost identical to those on the PX80 and PZ85, with an oversaturated and bluish green primary point and slightly oversaturated reds. The [Colour] control in the [Picture] submenu was of little use as it affected both colour saturation and intensity in no uncertain terms, whereas [Tint] was greyed out unless presented with an NTSC video signal (the UK uses PAL system).

Benchmark Test Results

Dead pixels	None
Screen uniformity	Perfect
Overscanning on HDMI	0% with [Picture Overscan] set to “Off“
Blacker than black	Passed
Black level	Excellent
Black level retention	Stable
Primary chromaticity	Average; green oversaturated and bluish
Scaling	Soft
Video mode deinterlacing	Good; effective jaggies reduction
Film mode deinterlacing	Failed 3:2/ 2:2 cadence in all resolutions
Viewing angle	Excellent (> 150°)
Motion resolution	1080
Digital noise reduction	Good at baseline
Sharpness	Defeatable edge enhancement
Image retention	Mild during the first 200 hours
Posterization	Mild, though worse with poor source
Phosphor trails	Yes; severity depends on individual susceptibility
1080p/24 capability (PS3)	Accepts 1080p/24 video signal; no telecine judder
Input lag	On par with Samsung F96

Picture Quality

High Definition (Blu-Ray)

Any comments on the image quality of a Panasonic plasma HDTV (high definition television) must surely begin with praise of its black-level performance and shadow detail revelation. Although still marginally lighter than those found on Pioneer Kuros, the inky blacks on the Panasonic TH42PZ80 left us in absolute enthrallment while watching The Assassination Of Jesse James By The Coward Robert Ford on Blu-ray. The cinematographically stunning nighttime train robbery scene could have quite easily murdered any lesser flat screen panel, yet the Panasonic TH42PZ80 effortlessly depicted the contrast between light and dark (e.g. the train light flickering past the dark woods, and Jesse Jame’s silhouette against the blinding illumination) and nuances in the deep shadows with commanding finesse and authority.

The colours inside the movie itself are intentionally attenuated at source in keeping with the historical period, and so the Panasonic TH42PZ80 was not to be blamed for the picture’s lack of depth and dimensionality. Flesh tones appeared natural enough, but the mild green inaccuracies could be picked up by perceptive viewers during numerous shots of the wheat fields.

Unleashed by setting [Picture Overscan] to “Off“, the true HD 1920×1080 native screen resolution on the Panasonic TH42PZ80 lent incredible detail to certain camera shots in the film, for example facial close-ups of Jesse James (Brad Pitt) where we can appreciate his jawline stubble, and the crow’s feet around his perpetually anguished and penetrating blue eyes. The Panasonic TH42PZ80 flat screen plasma also handled 1080p/24 video signal from the PS3 flawlessly, betraying no sign of telecine judder in sweeping pans of the breathtaking Missouri landscape.

Standard Definition (Freeview Digital TV)

Without the aid of edge enhancement, the scaling quality on the Panasonic TH42PZ80 plasma HDTV was mediocre at best, so perhaps there is a case for sprinkling in a touch of overenhancement (by increasing [Sharpness] a couple of notches) for standard-definition content. We were also disappointed by no improvement in posterization in spite of the full HD native screen resolution, although these usually only reared their ugly heads with poor source (low bit-rate, highly compressed broadcast material) and during fade-in/ fade-to-black.

Given the lack of any meaningful film mode deinterlacing on the Panasonic TH42PZ80, it is advisable to feed the television with progressive video signals (i.e. let your external device perform the relevant pulldown) when watching film-based material (movies, American dramas like CSI) if you want to avoid seeing various deinterlacing artefacts (line twitter, moire, etc.)

PS3 Console Gaming

The combination of LCD-trouncing blacks, LCD-equalling brightness, almost blur-free motion handling and full high definition screen resolution brought Gran Turismo 5: Prologue to gloriously photorealistic 1080p fruition on the Panasonic TH42PZ80 plasma television. Input lag was non-existent, either measured objectively or assessed subjectively as we hugged the racing lines on the tracks.

As with all plasmas, there remained the risk of permanent screenburn, but this could be minimised by taking appropriate precautions and avoiding lengthy non-stop gaming sessions. Phosphor trails/ green flashes might pose a problem for susceptible viewers with high retinal persistence; we did not witness any.

Conclusion

Delivering excellent black level, revealing shadow detail, fluid motion, detailed resolution and natural colours, performance-wise the Panasonic TH42PZ80 is fundamentally a PZ85 minus the [Intelligent Frame Creation] technology which–truth be told–we’re not too keen on for various reasons. If you’re not overly bothered about the aesthetics of the television itself (the PZ85 probably edges the PZ80 in this regard) or the intrusive positioning of the third HDMI input, then the Panasonic TH42PZ80 would almost certainly represent a better bang for your buck than the PZ85 series.

What Is Gamma

… and why is it important. Many HDTVs will have a control, often tucked away under advanced settings in a picture settings menu, labelled gamma. User manuals are often unhelpful in explaining what the gamma control does and even the better ones may be less than specific with terms such as “adjusts the balance between bright and dark areas of the picture”. To know how to adjust the gamma control we need to know what it does and why, so read on.

Gamma is actually a throw-back to the days of CRT televisions. Look at the graph below which plots incoming signal level versus light output of a typical CRT TV.

Notice how an input voltage of 50% produces only 18% of maximum brightness. This non-linear relationship between input voltage and output brightness is inherent in CRT technology.

To correct this “defect” an inverse gamma curve, like the one below, is applied to the source material.

Combine the “corrected” input gamma black line and the “broken” CRT gamma red line and the result is a linear relationship between input and output (the yellow line).

So that was how it worked on a CRT TV!

Fast forward to flat screen displays and what do we find? Plasmas and LCD displays don’t behave like CRT screens – they are inherently linear devices – but the source material is all being corrected for the old CRT displays so there is a big problem. What we now need is to make the flat panel HDTVs behave as if they were CRT devices and this is what the gamma control should do. We need to turn the yellow line into the black curve.

A gamma setting of 2.2 is usually considered the ideal setting and though some manufacturers offer adjustments with choices such as 2.0, 2.2, 2.5 etc. selecting 2.2 doesn’t necessarily guarantee that 2.2 is what you get. The only way to be sure is to measure the display’s output with a video analyzer and doing so is an essential part of an ISF calibration.

In the absence of a video analyzer can it be done by eye? Possibly, but you need to know what to look for! If gamma is set too low the picture will appear to be “washed out” whereas if set too high shadow detail close to black will be lacking.

The user manual that advised that the gamma control “adjusts the balance between bright and dark areas of the picture” tells the truth but isn”t too helpful. One more graph may help:

Big differences are apparent on the graph in the mid range (30 – 70 % input voltage). What does this mean in practice? Here are three screen captures, with gamma set to low (e.g. 1.5), normal (e.g. 2.2) and high (e.g. 3.0).

Example photo of low gamma (e.g. 1.5)

Example photo of normal gamma (e.g. 2.2)

Example photo of high gamma (e.g. 3.0)

Look at the mid range first. Low gamma (e.g. 1.5) produces a picture that looks “milky”, it looks flat and lacks punch. High gamma (e.g. 3.0) has loads of punch but now look at detail in the black areas – it has gone. Normal gamma (e.g. 2.2) gets the black detail and a picture that is crisp.

Setting gamma correctly is just one part of accurately calibrating an HDTV but it is an important part.

Piers Clerk
ISF Calibrator
www.homecinemaengineering.com

© Home Cinema Engineering Ltd. 2008

Toshiba 37XV505DB / 37XV503DB Review

The Toshiba 37XV505DB is the first of their Regza XV range of LCD televisions we managed to get our hands on to review. Replacing the ever-so-popular Regza X series, the new Toshiba XV LCD TVs feature true high definition (HD) 1920 x 1080 native screen resolution, “Luma Sens” technology which automatically adjusts the LCD backlight depending on the ambient light detected to improve blacks and save energy, a full power down mode which consumes even less power (compared to standby), and a dedicated game mode that decreases input lag for better gaming experience.

While researching this LCD HDTV on the internet, you may have come across different model names such as Toshiba 37XV503DB and Toshiba 37XV505DB. They are essentially the same panel (in terms of specifications and presumably picture performance) bar some minor cosmetic differences. However, some retailers have taken advantage of this difference in model name to refuse price-matching requests which may erode their profits.

Here’s our full Toshiba 37XV505D review.