are all plasma TVs this bad...?

RR7

Standard Member
I just bought a Panasonic TX-P37X10B, and in short the more white there is on the screen the dimmer the whole screen gets, a screen full of white looks pale grey.

TV shop just came out as i reported it as a fault, and the swapped it with an identical model, and it does exactly the same thing.

I called a friend who tried the same experiment on his 40" LG plasma and said it also does this.

when i called panasonic they said it sounds faulty but now it looks more like Plasma TVs cannot display consistent colours and brightness depending no how much power they are draining.

in all the documents i've read Plasma Vs. LCD this isnt mentioned.

i've turned all the eco mode and dymaic settings off, as did the TV shop bloke, he confirmed to me that the issue i've descibed indeed exists given that he could see it in front of him, but admitted i'm the first to point out such a thing.

to reproduce the problem one only has to have say, an animation of windows desktop, open a window with a white back ground and scroll it on and off the screen and watch the display get brighter and dimmer.

so my question is, is this a common Plasma thing that just most people fail to notice? or is there a price bracket or technology to overcome this? as it stands i'm returning the TV for a refund if there is no alternative model.
 

Phil Hinton

Editor
Staff member
What sources do you have connected where you notice this. What picture preset are you in? Have you set the brightness and contrast using any test patterns or by eye. How high do you have the contrast/brightness controls. What TV technology are you coming from to Plasma.
 

RR7

Standard Member
i've tried all picture modes, dynamic with full contrast exaggerates the problem as yo uight expect, but it happens in all screens modes and all presets, the TV shop guy tried everything.

i've tried it with SD card pictures and test cards, DVB-T, HDMI 720p connected to a PC, VGA and SCART input.

i have an LCD on my pc so i'm used to that picture, but this plasma has replaced a normal CRT, which while lacking the high definition, had far more consistent image contrast/brightness.

i'm no videophile, but my wife (who wouldn't know plasma from LCD if you told her) noticed the bad picture before i investigated and nocticed it.
 

RR7

Standard Member
looks like this is called ABL and a standard plasma TV feature.

i'm amazed this ABL effect isnt measured or mentioned in reviews, the effect on this panasonic is very pronounced.
 

boxrick

Member
Not sure what you mean by "ABL" ( I assume auto back light? ) Plasma screens do not have a back light therefore this is not the issue but not too different.

The issue sounds very much like "floating blacks" do a search on here for them. It is NOT a standard Plasma feature but a result of Panasonic messing with the screen brightness depending on what content is on the screen so the brightness will darken then lighten to try and increase the contrast yet in the real world it simply distracts and annoys. A real sinner of this was last years samsung LED based screens and many LG lcd panels.

Last years Panasonic 2009 screens did not have this issue neither did Pioneer plasmas or many other screens.
 

boxrick

Member

adbailey18

Well-known Member
I've been thinking of buying a TX-P46G20 and looking through the owners thread there are various issues being mentioned, one of them 'floating blacks'.

I didn't really understand what it meant but after watching that I don't think I could cope with a TV doing that!!

The hunt for a new TV continues...
 

RustySpoons

Well-known Member
I just bought a Panasonic TX-P37X10B, and in short the more white there is on the screen the dimmer the whole screen gets, a screen full of white looks pale grey.
I've not seen a Plasma that doesn't do this, my PX70 does it, all the professional Panasonic panels do it in work along with the hitachi's.

It's more noticable when using the display as a monitor and you pull up a window with a lot of white in it, the screen changes brightness all over.

I don't know whether this is scientific or not but I assume it's to do with voltage, the power supply isn't able to provide enough power to drive all the pixels at full voltage.

Old CRT's used to suffer from this! some more so than others.
 

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