CNET Tests Point To Extent of Loss in Panasonic Plasma Black Level Performance + A THX Response

March 3rd, 2010 · 25 Comments · News, Plasma

Panasonic TC-P42G10-415

(March 3, 2010)  Reports regarding a rise in the black levels of Panasonic’s 2008 and 2009 plasmas led CNET’s David Katzmaier to investigate the controversy. Katzmaier queried Panasonic. In their reply to CNET,  a Panasonic executive confirmed:  2008 and 2009 model plasma HDTVs’ black level brightens as the panel ages to provide a 100,000 hour lifespan (link).

Katzmaier stated he would perform aging tests to measure the change in black levels. On Feb. 5, HD Guru deferred commenting until David published his test results.

Katzmaier (link) published  his results yesterday: Panasonic’s 2009 model TC-P42G10 and TC-P50G10 black level changed from .008 ft. lamberts to .023 ft. lamberts after 1500 hours.

In layman’s terms, the lowest black levels of these test models lightened enough to be noticeable in a dark viewing environment.

Panasonic advertises on HD Guru. Regardless, the increase of the black level of any HDTV over time is not desirable.

Is this condition limited to Panasonic, or do its competitors (LG and Samsung) plasma HDTVs black levels also rise? We don’t know.

Almost all the products reviewed at HD Guru (and most other home theater websites) are loaned from their respective manufacturers. We are not aware of anybody performing long term testing of HDTVs.

THX Responds

The Panasonic plasma series reported to lighten their respective black levels as they age, are also THX certified. Black level performance is one criteria of THX’s robust list of performance parameters.  We asked a THX spokesperson if their certification testing process includes aging tests.  Below is THX’s official response to HD Guru obtained by email.

“THX certification aims to reproduce the highest standards for image quality, color accuracy and signal processing performance for TVs right out-of-the-box. With any display product, stability during the aging process is always a concern. However, today’s display technologies offer far better stability than was experienced in the past. We are aware of the reports about the Panasonic displays and are gathering data on the models in question. Feedback can be sent directly to THX at [email protected].”

Have a question for the HD Guru?

Copyright ©2010 HD Guru Inc. All rights reserved. HDGURU is a registered trademark. The content and photos within may not be distributed electronically or copied mechanically without specific written permission. The content within is based upon information provided to the editor, which is believed to be reliable. Data within is subject to change. HD GURU is not responsible for errors or omissions.


25 Comments so far ↓

  • Shellyboy9

    Who’s to say this example of rising black levels is exclusive to Panasonic. Will anyone be truly surprised to find this problem is endemic to plasmas unilaterally. As much as I love plasmas, their strengths are being slowly equaled and outstripped by LCD’s and their offspring (Oled’s etc). Unlike plasma makers however, LCD manufacturers have been upfront about their products weaknesses. Why did plasma makers have to be outted by CNET in order to give us some transparency?

  • AllanG


    I am a loyal Panasonic use for the last30 years. And was going to buy one of the new sets this year. Because I believe in Plasma.

    Think I will hunt down a Pioneer instead.

  • xtrepador

    i use mi g10 at least 21 hours a day and the problem it,s getting worst and brigther i don,t think panasonic really cares about it,s loyal costumers. i was going to buy the vt25 NO MORE cause the issue will be still there my tv looks old compare to my 27 inch samsung in my bedroom wich has better blacks than my g10 wich i hate because is SUCKSSSSSSSSS.

  • Shaan

    any reports of people hacking their panny’s to adjust the voltage? Would be risky obviously, but I’m curious if anyone’s attempted it.

  • Steve

    Nothing new added here. Waste of bandwidth.

    And we do know that other plasma’s do not do this…D-Nice’s 4280HD measures 0.0063fL with 1800+ hours on it. That means a 720p Kuro from 2007 will best a 2010 VT25 after 1,500 hours. Sad.

    His 101FD, 500M and 141FD are still measuring in the 0.000xfL range

    Hopefully Panasonic gets the 2011 panels right…the waiting game continues. This pre-programmed rise in MLL is specific to Panasonic…and it’s clearly a bad decision.

  • Bervick

    To get an excellent explanation of the black level issue

    And here

    Adjusting the brightness of course will do nothing. Why would there be owners complaining otherwise.

  • James R Barton

    I own a 50PZ800U and my black levels have risen noticeably–anyone out there have information on the progress of the lawsuit? Thank You!

  • Shaan

    Would appreciate if someone could explain how raising the black levels does anything to extend the life of the set? Is it preventing burn-in somehow? Does it also raise the brightness levels all around? If so, why do the black levels have to be raised? Can’t the voltage only be increased when the pixel is turned on?

  • kissmeraas

    @Tzedekh I hope Panasonic do something about the rising black issue. I don’t even see why it’s necessary – these TVs will only last five or six years if you’re lucky, so why the hell does the panel need to last 100,000 hours? Even if you leave it on 24 hours a day 365 days a year, that’s ELEVEN AND A HALF YEARS. I’d rather they stopped the insides from blowing up after 12 months ;-)

    BTW, UK G10 & G15 models didn’t have 96Hz refresh – they had the flickering 48Hz. Only the V series got the 96Hz, same as these new 2010 models. Also we didn’t get THX mode and the controls were basically Colour, Contrast & Brightness! Also we didn’t get any bigger than 50″ in the G series. Plus they are WAY more expensive than the US models. Our 58″ V10 is $2000 more than your 65″ !! WE’RE the ones getting shafted…

  • Tzedekh

    Unfortunately, because of a class-action lawsuit over the issue of rising black levels, Panasonic cannot comment, let alone admit it made a mistake. If its pre-2008 plasmas had a 60,000-hour lifespan (until half brightness) without resorting to increasing black levels, then, at the very least, the 2009s and 2010s should also. Having to increase black levels to mediocre levels bespeaks cost cutting, and doing so without warning buyers in advance appears fraudulent. This is only the latest evidence Panasonic’s disregard for its consumers, particularly its U.S. customers, who have been getting fewer and feature-reduced models for years. For example, the midlevel (i.e., G10 and G15 series) European models have better image controls and 96-Hz refresh. Sure, they cost more than their U.S. counterparts, but just about everything costs more in the UK and Europe than in the U.S. I think Panasonic should apologize for this bias and fix it by implementing the features–and shut off the black levels brightening–in the 2009 and 2010 U.S. models via firmware. Nothing helps public relations like a mea culpa and penance, something Toyota learned too late.

  • TamingOfTheShrew

    Proof that people will lie if they think they can get away from it. At least HD Guru confronted the issue before (head in the sand) Consumers Reports.
    Pioneer gone, Samsung’s buzz and now Panasonic. Add in the new meaningful California Energy Standards and it spells the death of Plasma.

  • Charles

    I will be writing to Panasonic to let them know that I was planning on buying one of their VT25’s this year but after seeing how they handled the rising black and image retention issues I will not buy a Panasonic TV. There is obviously some serious issue with how they implemented their adjustments but instead of acknowledging it and working on a fix they’re giving a big middle finger to their customers. That is not how I want to be treated so I will be buying a different brand of HDTV. They may be saving money by ignoring current customers but their actions will also cost them future sales as well.

  • Adam

    cnet says it’s equal to a fairly high LCD after their 1,500 hours of testing.

  • Paul Belanger

    This is not the first time Panasonic “pulled” a “bait-and-switch” with THX.

    About 12 years ago Technics (a division of Panasonic) had a 2-ch THX power amplifier which during the production run, Panasonic changed the spec while maintaining the THX logo.

    now… this.

  • Charles

    I bought my 50V10 due to the positive reviews from HD-GURU and CNET, particularly pertaining to excellent Blacks/grey-scale/THX abilities.

    I have no meter readings but from around 1200hrs I noticed bad IR occurring and light greys on empty AV screens.

    THX has always been greenish and this set NOW views as a low grade LCD panel.
    Panasonic haven’t heard the last from me.

  • etype2

    It will be interesting to see THXDISPLAYS response after they have time to evaluate the sets in question.

    Will they pull the certification?

    Bottom line for me, I hope Panasonic sorts this out with it’s customers and brings us outstanding televisions.

  • Bervick

    Thank you Gary / HD Guru. I had lost some faith in your reporting. But you’re publishing of this article has earned respect. And I’m sure it will be the same for other reviewers of your site.

    The THX response is particularly noteworthy. We were thinking of using that for leverage. It worked for us when we pushed for a THX fix.

  • Jimd

    I would rather have a TV with 50,000 hour lifespan with great black levels than one with 100,000 hour that increases black levels so quickly. Watching a 50,000 hour TV every day for 4 hrs/day means a lifespan of over 30 years. If all other components of the TV make it that long, the TV will still be usable but it will be half as bright. Does anyone that buys a high end TV is willing to sacrify black levels in order to have a TV that last more than 30 years?

  • Adam

    To complete the puzzle, compare the aged pictures of a panasonic with the algorithm, the same panasonic without it (if possible), and similar-quality screens of other brands. Look at all aspects of picture quality. Then there could be a class-action on firm footing or Panasonic could be cleared.

  • etype2

    … I meant, Please read the full … Sorry. :-)

  • etype2

    Sweet and short. Internal circuitry in Panasonic sets are self adjusting the black levels upward, automatically over time.

    Please the full commentary in other articles on this site.

  • etype2

    And let’s remember, Black level is ONE of the main advantages over LCD claimed by Plasma in general.

    I predicted a firestorm over this and now Panasonic has a class action law suit on their hands.

    Guru raised an interesting point, are other Plasma sets by other manufactures going to have the same problem?

  • RichF

    So if my set, when originally calibrated, was not at the minimum brightness setting I could adjust for this in a recal by lowering my brightness setting or am I totally missing what’s going on?

  • Wes Sokolosky

    According to Panasonic, essentially the same voltage increase algorithm is operative in 2010 models as well, though operating over a longer period of time. MLL increases have already been measured in a 2010 50S2 model. This certainly is worth noting for those for whom black level and contrast are important.

    Wes Sokolosky

  • george hembree

    top rated 42in tv for 2010. does sony have new tv technology for 2010. is laser tv near or far away? thanks george hembree

Leave a Comment