Rainbow effect on Panasonic VT20 Help Please

flyer

Active Member
Had my TXP50VT20 for about 3 weeks but just started to notice a rainbow effect on people's face if the pull back fast.

Any advise appreciated, it appears as a Red and green type lines around their faces as they move?

Thanks

Ian
 

Chronoptimist

Novice Member
Normal for plasma I'm afraid. If it was another plasma without the quick phosphors the VT has it would be green and blue lines you would see and they would be more obvious.
DLP has similar issues but has mostly fixed it with high-speed color wheels and LED lighting. (reduced well below plasma now)

LCD will sometimes show green lines around moving objects if you have the backlight turned down low but much more rarely.
LED screens do not have any problems like this at all.
 

panman40

Distinguished Member
Had my TXP50VT20 for about 3 weeks but just started to notice a rainbow effect on people's face if the pull back fast.

Any advise appreciated, it appears as a Red and green type lines around their faces as they move?

Thanks

Ian
Im afraid that's what's called Posterization/False Contouring, Common on the 2010 Panasonic Plasmas, unfortunately there is very little you can do to eliminate this:( hence one of the reasons i returned mine,
However contary to the post above NOT all plasmas do this ;):)
 

Chronoptimist

Novice Member
Im afraid that's what's called Posterization/False Contouring, Common on the 2010 Panasonic Plasmas, unfortunately there is very little you can do to eliminate this:( hence one of the reasons i returned mine,
However contary to the post above NOT all plasmas do this ;):)
It sounds like this is phosphor lag not posterization. Phosphor lag on the Panasonics with new phosphors is red and green, not blue an green like on older plasmas and would affect the whole face not just the edge of it.
 

panman40

Distinguished Member
It sounds like this is phosphor lag not posterization. Phosphor lag on the Panasonics with new phosphors is red and green, not blue an green like on older plasmas and would affect the whole face not just the edge of it.
No, The Posterization in faces on the VT20 is Red/Green i can assure you
 

Chronoptimist

Novice Member
No, The Posterization in faces on the VT20 is Red/Green i can assure you
:(

If it is posterization then other plasmas will be significantly better for it. (but it still exists) Panasonic have always been bad with it but seem to have made it worse recently.
 

death valley

Novice Member
No, The Posterization in faces on the VT20 is Red/Green i can assure you
I think your both right: it is a 2010 pana problem (so not all plasma's have it, my old pana doesn't show these issues) but I think it's not posterization since when you freeze the picture you don't see it: if it were posterization you still would see it, if I'am correct

you can minimize these effects by turning IFC to on but that gives rise to other issus, do these can be less disturbing
 

paulr2006

Distinguished Member
I think your both right: it is a 2010 pana problem (so not all plasma's have it, my old pana doesn't show these issues) but I think it's not posterization since when you freeze the picture you don't see it: if it were posterization you still would see it, if I'am correct

you can minimize these effects by turning IFC to on but that gives rise to other issus, do these can be less disturbing
Agreed, I see posterization on some broadcast material (never on Blu ray) on my VT20 but in 9 months of ownership of my previous V10 never saw it once.:)
 

Chronoptimist

Novice Member
Agreed, I see posterization on some broadcast material (never on Blu ray) on my VT20 but in 9 months of ownership of my previous V10 never saw it once.:)
Lower quality sources will make it more obvious.

Search for "purple snakes" here for info on older plasmas. Was definitely still an issue.
 

Avi

Distinguished Member
LCD will sometimes show green lines around moving objects if you have the backlight turned down low but much more rarely.
LED screens do not have any problems like this at all.
They do however have other issues caused by the sample and hold drive technique used by LCD/LCOS. This causes some people to experience blur/smear during motion. It's down to physiology and varies from person to person so it's choose your poison.

Avi
 

paulr2006

Distinguished Member
Lower quality sources will make it more obvious.

Search for "purple snakes" here for info on older plasmas. Was definitely still an issue.
Agreed, it's only ever on low bitrate broadcast material but I have never seen the purple snake effect or even heard of it on the V10, It was however apparent on earlier models.
 

hodg100

Distinguished Member
I think the faster phosphors theory doesn't really ring true; the same effect is present on both G and V20's - unless they sneeked them in to those models too. In which case I'm going to ask my dealer for a phosphor translpant.

It's certainly not restricted to low quality sources on the G20 either:thumbsdow
 

paulr2006

Distinguished Member
I think the faster phosphors theory doesn't really ring true; the same effect is present on both G and V20's - unless they sneeked them in to those models too. In which case I'm going to ask my dealer for a phosphor translpant.

It's certainly not restricted to low quality sources on the G20 either:thumbsdow
:laugh::)
 

Chronoptimist

Novice Member
They do however have other issues caused by the sample and hold drive technique used by LCD/LCOS. This causes some people to experience blur/smear during motion. It's down to physiology and varies from person to person so it's choose your poison.
Plasmas are sample & hold displays too. They rely on it for you to perceive the subfield driving as a full color image.

Most of the better LED sets use a scanning backlight to eliminate sample & hold effects. The Sony HX900 scored top marks for motion resolution with it enabled.


I think the faster phosphors theory doesn't really ring true; the same effect is present on both G and V20's - unless they sneeked them in to those models too. In which case I'm going to ask my dealer for a phosphor translpant.

It's certainly not restricted to low quality sources on the G20 either:thumbsdow
The phosphors used have no effect on posterization. They do have an effect on the severity and color of phosphor lag. Most people see green/red edges on moving objects on the VT20 series with the new phosphors. The older ones have green/blue edges.

If you are seeing something else its likely posterization.
 

hodg100

Distinguished Member
The same colouration occurs on the G as it does the VT. I was just debunking the idea it's down to the phosphors:)
 

toodeep

Member
Not necessarily. Maybe it is expedient for Panasonic to use the same phosphors across the G/GT/V/VT ranges despite the marketing.
 

Chronoptimist

Novice Member
Not necessarily. Maybe it is expedient for Panasonic to use the same phosphors across the G/GT/V/VT ranges despite the marketing.
They definitely do not. Posterization is a software processing & panel driving issue.

Phosphor lag color and severity is affected by the phosphors used. On the GT and VT sets it typically shows as green/red image separation.

On most other plasmas it shots as green/blue image separation.

He is probably talking about posterization not phosphor lag which looks like this on most plasma.

http://www.avforums.com/forums/plasma-tvs/1340863-blur-effect-ghosting-judder.html#post13206093
 

hodg100

Distinguished Member
They definitely do not. Posterization is a software processing & panel driving issue.

Phosphor lag color and severity is affected by the phosphors used. On the GT and VT sets it typically shows as green/red image separation.

On most other plasmas it shots as green/blue image separation.

He is probably talking about posterization not phosphor lag which looks like this on most plasma.

http://www.avforums.com/forums/plasma-tvs/1340863-blur-effect-ghosting-judder.html#post13206093
No, I'm saying the G displays the same green/red image separation as the 3D TV's. What's so difficult to understand:confused:

I've discussed it countless times with V/VT owners and it occurs in the same places at the same time. I've also had the 'pleasure' of seeing it on the V & VT myself.

Your phosphor theory is incorrect.
 

panman40

Distinguished Member
I think the faster phosphors theory doesn't really ring true; the same effect is present on both G and V20's - unless they sneeked them in to those models too. In which case I'm going to ask my dealer for a phosphor translpant.

It's certainly not restricted to low quality sources on the G20 either:thumbsdow
Absoloutely agree it was not just on poor bitrate SD Sources ;):)
 

Chronoptimist

Novice Member
No, I'm saying the G displays the same green/red image separation as the 3D TV's. What's so difficult to understand:confused:
All I am saying is that there are two issues that could cause this. Phosphor lag AND posterization.

If it is green/red separation you are seeing on a G series plasma then that must be posterization because the double-images caused from phosphor lag are green/blue on them.

Phosphor lag on the VT can show as green/red separation instead of green/blue like on normal plasmas due to the new phosphors. I am saying what he could be seeing could be EITHER posterization or phosphor lag on a VT series plasma.


I am not arguing with the fact that it happens or that it sucks.
Pictures are always helpful for identifying problems. The difference between posterization and phosphor lag should be obvious in a photo.
 

Inferno

Distinguished Member
All I am saying is that there are two issues that could cause this. Phosphor lag AND posterization.

If it is green/red separation you are seeing on a G series plasma then that must be posterization because the double-images caused from phosphor lag are green/blue on them.

Phosphor lag on the VT can show as green/red separation instead of green/blue like on normal plasmas due to the new phosphors. I am saying what he could be seeing could be EITHER posterization or phosphor lag on a VT series plasma.


I am not arguing with the fact that it happens or that it sucks.
Pictures are always helpful for identifying problems. The difference between posterization and phosphor lag should be obvious in a photo.
No what you are trying to do is worm your way out of something else you have wrong AGAIN!!! And its not the first time is it chrono???

Why dont you just go and post in the lcd/led section, what id give to be a moderator.
 

paulr2006

Distinguished Member
No what you are trying to do is worm your way out of something else you have wrong AGAIN!!! And its not the first time is it chrono???

Why dont you just go and post in the lcd/led section, what id give to be a moderator.
Could not agree more, this forum used to be quite a nice place to be but theres always one ;)
 

Chronoptimist

Novice Member
No what you are trying to do is worm your way out of something else you have wrong AGAIN!!! And its not the first time is it chrono???

Why dont you just go and post in the lcd/led section, what id give to be a moderator.
See post #6 where I agree that it may be posterization.

You pick and choose what parts of my posts you read and follow me around the forums to berate me.

Every time I post, there you, paul or insanity are. Dont you all have anything better to do? You cannot bully me into submission. I may have been wrong here initially but that does not change the fact that this is one of many plasma issues that lots of people are not aware of, and that people like you are trying to sweep under the rug because you bought a plasma and feel you have to justify your purchase.

This is yet another example of someone buying a plasma not being aware of a prominent issue that they suffer from, having found out the hard way as a result.

http://www.avforums.com/forums/13167046-post452.html

1. Phosphor lag on the lines, posterization on the pitch (green mush)
2. Posterization on faces, phosphor lag on shirts
3. The worst posterization I have ever seen

I was mistaken about it being phosphor lag, I was under the impression it was red/green on the VTs. (sure I had seen that before) Looks like it is still blue/green and what I had seen was posterization.



This still does not change the fact that it is a plasma issue though it is significantly worse on Panasonics than any others. All plasmas posterize to some degree though. Depending on the driving method used they will either posterize all the time but to a lesser degree and make up for it with lots of dithering resulting in a noisy image (Pioneer) or posterization will increase with movement as you see on Panasonics.

If you dont want this to happen, you need to buy a display thats not Plasma or DLP. (but any other plasma make and most DLPs will show it much less)
 
Last edited:

Insanity202

Distinguished Member
Them pics are of the 50hz issue. :rolleyes:
And I dont see that on my lg or my g10(now gone due to the mll issue)

And why are we here? well because we own plasmas and love to talk about this tech, thus we post here and read here. Just another hobby in a list of many. :D
 

paulr2006

Distinguished Member
No what you are trying to do is worm your way out of something else you have wrong AGAIN!!! And its not the first time is it chrono???

Why dont you just go and post in the lcd/led section, what id give to be a moderator.
Can't make my mind up if he is a disgruntled ex -Panasonic employee or a current Sony employee, whichever it is he certainly has issues & should not be lurking around the plasma section :D:)
 

The latest video from AVForums

Podcast: Marantz SR7015 & NAD T 778 AVR + Mission LX2 MKII Speaker Reviews, AV & Film News and More

Latest News

LG SIGNATURE OLED R TV now available in South Korea
  • By Andy Bassett
  • Published
LG Display teams with Disney for OLED Projects
  • By Andy Bassett
  • Published
Campfire Audio updates Vega and Dorado earphones
  • By Andy Bassett
  • Published
Oppo launches S1 and R1 4K smart TVs
  • By Andy Bassett
  • Published
Lithe Audio AirPlay 2 ceiling speakers world's first
  • By Andy Bassett
  • Published
Top Bottom