Panasonic Viera TX-P50V10 plasma - Flicker and poor pixel mapping

[ScoobyTV]

Hi everyone,
I've had my Viera V10 (TX-P50V10B) for a few days now and I have to say I'm massively unimpressed, mainly because the thing gives me migraines every day I'm using Freesat and a PC connected through HDMI. There is a definite issue with both sources in the form of a definite flicker.

With or without IFC I was expecting a rock-solid image. But even if the panel were only displaying 25fps for TV, I thought IFC would help ensure a rock-solid image, especially since it's supposedly generating 600 frames a second, but even if it were only 100 the image would be solid with no noticeable flicker. It makes no difference to the flicker whether IFC is turned on or off.

I've not noticed a screen flicker since Ye Olde Days of old CRT monitors for PCs which would give me massive headaches too. The flicker is noticeable on bright areas especially on any source. At its worst, from a normal sitting distance the whole image can be seen to flicker with only the very centre of my vision appearing most stable. The EPG is a guaranteed way to demonstrate it due to its bright banner at the top and flat colours all over - the whole thing flickers.

In normal viewing obviously it depends on the image being shown, but in general terms the brighter the image the more obvious the flicker is. Turning down the brightness and contrast only eases the problem, it doesn't cure it, and to my mind the image should be solid.

The panel seems incapable of displaying a solid image, and I'm mightily unimpressed. This dismal performance isn't source-specific, and being able to use a PC to provide known images, test patterns etc. shows the panel's weaknesses.

Poor grey rendering and general instability
The panel is unable to display greys well. Dark greys are displayed as dark grey with what can best be described as "swarms" of lighter grey pixels moving randomly. These are clearly visible close up but from a distance this constant shimmering may be a contributing factor in the perception of flicker. Light greys work the opposite way - light background with a swarm of darker pixels. Mid-greys work somewhere in between: the grey of the EPG looks pretty neutral by comparison since it is neither dark nor light enough to show up the swarming effect, but still has a definite shimmer to it - not in terms of the image wobbling its location slightly, but in terms of instability. This may be a component of the visible flicker.

PC Issues
Connected with HDMI, running at the panel's native 1920x1080 at the maximum 60Hz, I have the following issues:

Pixel Mapping issue?
The pixel mapping seems misaligned and there is no way to adjust this in my display properties or in the TV's menus. Edges of windows, fonts etc. have a visible green halo in the pixel to the left, and a magenta halo in the pixel to the right.

I've not seen anything like this on ANY modern screen with a 1:1 pixel mapping. I do not have any sub-pixel font rendering like ClearType turned on, and in any case this issue is visible on any higher-contract boundary such as the edge of a window.

Unstable blues, variable reds
The panel is again unable to display a solid image. Calibrating the gamma using nVidia's control panel, you are presented with familiar RGB bars, where the top and and bottom section of each bar is rendered as a checkerboard pattern of red/green/blue and black pixels, with the centre of each bar being full red/green/blue which you slide to match the checkerboard pattern - standard stuff. The checkerboard pattern seems to cause this panel particular difficulty and highlights some fundamental weaknesses.

Without IFC on, the checkboard of blue and black pixels flickers like crazy, making adjustment of gamma for blue impossible. The flicker is more obvious than the 60Hz signal it is being fed - it's really jumpy. Red is solidly displayed, and there is a very slight flicker on the green pattern.

With IFC turned on, the red checkerboard pattern joins in and flickers like crazy too.

Having spent £1500 on this TV/panel, frankly I was expecting something excellent that would be good for both TV and HTPC viewing, and better than my 5-year-old LCD at both. What I've got is something far worse, the likes of which I've not seen since old CRT days.

So, the question is: has anyone else had these or similar issues with their V10? Is mine "normal" or is it defective? Obviously I can't tolerate a panel that gives me repeated migraines!

[screemer]

I am having ongoing flicker issues with my 42 V10. A lot of people on here and other forums suggest its individual perception, but i still believe its some sort of fault. I am getting a panasonic service agent out to mine.

[kev.]

Personally I think some of the screens with the G10 and V10 are faulty

You should get a replacement,

Does this happen in THX mode?

[ScoobyTV]

Hi Screemer, thanks for your response. Snooping around the V10 owners thread I had found your posts about yours flickering.

Looking around I've also found some more explanations about how plasmas work - the pixels are on or off (though how the brightness setting would then work I don't know but hey) so I think that explains the swarming/dithering that I'm seeing in grey tones. It needs to switch the pixels on and off rapidly. That covers a part of my issues. The poor pixel mapping is a crock as far as I'm concerned and no amount of fiddling with the settings can get it sorted.

The specs for this panel give its response time as 0.001ms if I remember rightly. I wonder if this contributes to making flickering worse on these new panels.. I don't notice phosphor trails so I'm guessing they return to their "off" state very quickly too on these new NeoPDPs. This ability to do rapid on/off would therefore make flicker more pronounced. In that case though, they should be able to display more on/off images per second and so get something that can be perceived as a solid image. Even if the fade to the off state for a phosphor took the better part of 5ms, that would still allow the panel to refresh at 200Hz, which would make flicker imperceptible. It was doable on CRTs 15 years ago, it should be doable now! Except that it needs to use some of that refreshing to generate the correct colours from all the on/offs. Hmmmmm.

I find my panel isn't fit for purpose as a TV though, since I can't actually watch TV without affecting my wellbeing! I feel pretty wiped out today because my head is splitting


Kev - thanks for the idea, I've just tried the PC in THX mode with some nice desktop windows to show flicker-tastic areas, and it makes a little difference. I noticed though that on a white screen (Freesat or PC), THX's colour temperature is warmer and more red. With the insane flickering I noticed previously on the blue checkerboard pattern it could be because the image has less blue in it that the flicker is a bit less noticeable - if the blue phosphors are a big player in the flicker of these panels.

Another thing I've noticed, which is dead easy to do on a PC where you can control the image yourself, is if you take a light window, and move it around the screen, on and off the screen, the clarity of the whole panel changes like it's trying to ensure a consistent display but actually it fouls it up. With a window present, the rest of the display is darkened so it loses detail. Take the window off and everything gets brighter and clearer again. You can see a similar effect with the panel's own menu screens too. In Ye CRT days, the inability of a screen to maintain a decent image was an indicator of poor electronics or voltage control. I'd be interested to know if anyone else's V/G10 does similar.

I've also noticed that windows seem to affect the image way beyond their bounds. For instance, the title bars cause a lighter strip running the full width of the screen either side of the window. You can see the same effect with the TV's own menus, so I know this is not an issue with the signal from the PC. In the TV's menus, the selected row, e.g. in the Picture menu, causes a visible horizontal area in the picture to the side of the menu that is slightly different in brightness to the rest of the image, like ghosting but a constant horizontal band rather than an echoed image of the menu.

[bfg500]

You guys must have faulty panels. No flickering of any kind on mine. I use Cinema and THX modes.

[screemer]

i am convinced that mine cant just be my eyes. I have now had many family memebers come round. most of whom are totally non-understanging about tv's, and they can see it. All these poeple cant have this same sensitivity

[Jim Di Griz]

Screemer...

This doesnt help but I suffer from migraines too (the non-visual kind) but it isnt connected to the TV Im very sure of that. Theres all kinds of triggers for migraines, with me, wine seems to be a major trigger (unfortunately) and Im suffering a bit today because of that.

The flicker must be awful to cause a migraine I would have thought - if I even suspected for a second that my TV was causing my migraines I would get rid of it - I know its not though.

Maybe see if you can demo some other G10s and V10s to see if you can see the same thing as you get on yours?

Must be a faulty set? If not - I think youre gonna have to think about another plasma range or....an LCD

[metric]

I went through 3 faulty 50" g10s and my 3rd one had the very same problem the op had and i was getting terrible migranes from the flicker. The first 2 didnt do it only the 3rd, also the colours looked off. I got a refund and got a 50" v10 instead and theres no flicker with this one and viewing it is a pleasure. Ive read about others with the same problem who had to get it exchanged and it was fine. So it deffinetly seems like a fault with some sets. Id advise to get an exchange as the tv is excellent when fault free.

Edit: oh yea the set with the flicker also had terrible motion, it was very painful to watch, the tv actually gave me the worst sore heads i have experienced, i didnt know what a migrane was.

[Graham]

Hi

I've seen a 50v10 in a shop and saw flicker in areas of light picture - playing a black & White western on freeview it was pretty unsubtle to be honest. Changing channels I couldn't repeat the effect on channels with lots going on or with dark backgrounds. I had a look for about 15 minutes in total. I also looked at a g10 today next to two lcd's, all playing the shop's promo feed. The two lcd's were very stable but the g10 on a white background showed the same kind of flickering wherever there was white in the image. Maybe it does just affect some people - I've had a panny 42pz70 for two years though and it's never flickered. Very disappointing as I was very tempted by the v10. Maybe as people have said it's an individual thing like sensitivity to DLP rainbows (which I also get)

[Paul Ennis]

It's not a 'faulty' set. Every g10 and V10 I have seen does it. I have looked at c.40 different G10's / V10's and they all do it. It sucks. In my opinion, it ruins an otherwise good TV.

[Buckster]

I still get the impression that these "issues" - can't be the panels themselves (I'm guessing here by the way) - but something else

either the software or possibly power supplys/regulation ?

if its the panels then how come I've never seen these complaints on any of the Pro panels ... which use the same panels - with just a different front screen and different processing ....

(yes I know there are no G10 versions yet - but the ..8xx series suffered from similar symptoms of flickering, and the PF range of Pro panels used same panels with no flicker )

perhaps its like in high end audio components

the power supply is quite critical to the end result - and perhaps on a large power hungry, and technically complex plasma panel - the power supply is even more important

I'd be more convinced from an electronic engineering point of view of variations in samples of PSUs in each set than differences in the panels themselves - which are built to very high standards I think ?

[screemer]

It has that appearance of it not getting enough power.

[Paul Ennis]

Funny, I had exactly the same thought.

Originally Posted by Buckster

I still get the impression that these "issues" - can't be the panels themselves (I'm guessing here by the way) - but something else

either the software or possibly power supplys/regulation ?

if its the panels then how come I've never seen these complaints on any of the Pro panels ... which use the same panels - with just a different front screen and different processing ....

(yes I know there are no G10 versions yet - but the ..8xx series suffered from similar symptoms of flickering, and the PF range of Pro panels used same panels with no flicker )

perhaps its like in high end audio components

the power supply is quite critical to the end result - and perhaps on a large power hungry, and technically complex plasma panel - the power supply is even more important

I'd be more convinced from an electronic engineering point of view of variations in samples of PSUs in each set than differences in the panels themselves - which are built to very high standards I think ?

[ScoobyTV]

I have noticed a faint noise from the panel when there is no audio. A hum is the wrong way to describe it. It certainly sounds power related though, as it sounds to be around 50hz, but like lots of little clicks or ticks very rapidly making for a slight buzz. Does anyone else's do this?

For the sake of process of elimination I've tried the TV in its own socket rather than the 4-way block it's currently sharing (even though the other devices are all switched off at present), but it made no difference. I did notice mine flickering in the shop though it was attributed to the fluorescent 50hz lights they had, and it seemed better when they were switched off. I have no such lighting here though and there's definitely something going on.

Whether they all do it as some indicate, or whether it's only dodgy ones I think it's pretty unacceptable for a TV to be like this. I wish I'd gone for the LCD I was originally thinking of, and to be honest I don't really notice any benefit in terms of picture contrast -when the screen is switched off it's a grey colour anyway much like an old CRT and that is naturally the darkest shade it can manage to produce, especially in daylight conditions. "Infinite Black"?

I'll also try Panasonic's customer service and see if they view it as a faulty set. I hope they do as it'll give me some ammo to go back to the shop with.

[Paul Ennis]

I think it's pretty common for Plasma's to buzz a little bit, my G10 does it, but it's at a level I don't find obtrusive.