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Plasma & Rainbow effect - like DLP

9K views 29 replies 18 participants last post by  Skram0 
#1 ·
Just purchased a Plasma the other night (Panny GT25) and I am experiencing what is like the rainbow effect for which I suffer horribly on DLP. The only difference is on the plasma it is not that bad (not even close to how bad it is for me on DLP) and it is more yellow and white banding instead of the bright RGB coloring I experience with the DLP. Anybody else suffer from this? Is this the "flashing" some people with plasma's talk about? Just looking for answers, not looking at returning the set. At least not unless Costco starts showcasing the VT series in the next 85 days.


TIA.


Bryguy
 
#2 ·

Quote:
Originally Posted by bryguy /forum/post/19840013


it is more yellow and white

The yellow banding is due to the phosphor 'lag'. It's an inherent side-effect of plasma technology. Pioneer's TVs still have the least amount of viewable lag. Consider your TV "as-is" since there's no setting that reduces the effect. It's dependent on the technology used by the manufacturer to help reduce it. ...Welcome to the plasma community
 
#3 ·

Quote:
Originally Posted by Acid Snow /forum/post/0


The yellow banding is due to the phosphor 'lag'. It's an inherent side-effect of plasma technology. Pioneer's TVs still have the least amount of viewable lag. Consider your TV "as-is" since there's no setting that reduces the effect. It's dependent on the technology used by the manufacturer to help reduce it. ...Welcome to the plasma community

This is not true, Pioneer had more than the Panasonic VT series. Try turning your contrast down, I got rid of an Elite for this same reason, this is one area Panasonic beats the Elite, at least on the VT series. I would get rid of the G series for the VT series. The 3D Panasonic has very little phosphor lag, this is why they have excellent 3D performance.
 
#6 ·
The effect is not that bad that I can live with it. My wife does not see it. When watching any DLP it is like being on hallucinigens. We use a high quality DLP projector at work for meetings and it drives me nuts. Doesn't matter if the room lights are on or off. As for the plasma, I see it more in the dark then with lights on. Since I've been an amateur astronomer since I was a little kid (going back more than 30 yrs) my eyes and quality of visual observation are much more advanced. Even sitting in a painted room that was not painted by a spray gun I pick up every brush or roller patterns.


Since I bought it at Costco I've got almost three months to return and upgrade but for now, it's a keeper.


Bryguy
 
#7 ·
For me, the rainbow effect on single chip DLP projectors in UNBEARABLE; every time I move my head (or eyes) even slightly, I see rainbows galore.


On my 5-year old Panasonic plasma TH-50PHD8UK the effect is different (yellow and white trails), and depends more on the material I am watching. It is not as offensive to me, and I can live with it.


It has to do with different decay time on different phosphors.


I hope not to see it on the new 3D plasmas in which the decay time got more uniform, and faster.
 
#10 ·
I just picked up a Panasonic VT60 and I'm seeing the rainbow effect too. As someone above mentioned it's only really noticeable with white text on a black background. I've had one of each of the last 3 generations of the Pioneer plasmas and have never seen it before. I wonder if it happens with the ZT60 too...
 
#11 ·
^^^ Yes, I can see them on my ZT60.


Some have posted this is phosphor lag. I don't think so. Rainbows are different, because I see them when I move my eyes, not when my eyes are still and an object moves on the screen. Plasmas must be illuminating their RGB subpixels in a cyclical manner, like a DLP cycles through RGB strobes. When you move your eyes across the screen, some peoples' eye/brain make up is such that they can see the individual RGB strobes for bright white objects because each color is strobed when the eye is at a different position (the eye moves fast). That's my theory anyways.


Three things I have found helps:
  1. Increase ambient light (eg. use a bias light, or turn on a lamp).
  2. For problematic scenes, keep eyes still.
  3. Reduce contrast.


I had a DLP for 10 years. Eventually I just stopped noticing rainbows. I guess my eyes adjusted. I can still see them with my plasma after 4 months, but I'm rarely bothered by them. Nice thing is that I don't seen them at all for low contrast material like sports, or when watching TV in the daytime.
 
#12 ·

Quote:
Originally Posted by sooke  /t/1307543/plasma-rainbow-effect-like-dlp#post_24056221


^^^ Yes, I can see them on my ZT60.


Some have posted this is phosphor lag. I don't think so. Rainbows are different, because I see them when I move my eyes, not when my eyes are still and an object moves on the screen.

Same here.
Quote:
Plasmas must be illuminating their RGB subpixels in a cyclical manner, like a DLP cycles through RGB strobes. When you move your eyes across the screen, some peoples' eye/brain make up is such that they can see the individual RGB strobes for bright white objects because each color is strobed when the eye is at a different position (the eye moves fast). That's my theory anyways.


Three things I have found helps:
  1. Increase ambient light (eg. use a bias light, or turn on a lamp).
  2. For problematic scenes, keep eyes still.
  3. Reduce contrast.


I had a DLP for 10 years. Eventually I just stopped noticing rainbows. I guess my eyes adjusted. I can still see them with my plasma after 4 months, but I'm rarely bothered by them. Nice thing is that I don't seen them at all for low contrast material like sports, or when watching TV in the daytime.

I would add "Blink when you move your eyes" to that list.


One of the most (the only?) amusing features of this phenomenon is that I can track a moving object with my eyes, and the picture will be perfectly fused, but the instant I let my eyes wander during the same scene, it's rainbows galore. Keeping the eyes still also works. And it's not just "bright white objects". Skin tones can cause a red flash when the skin appears against a dark background. I often notice this with hands against dark clothing near the bottom of the screen. Basically any color with red in it seems able to cause it on my 50ST60 and the 50S60 I had for a couple of weeks, and it's even more likely to appear when there are two bright objects separated by a dark color.


It's not quite a dealbreaker with the alternative being LED, but it's by far the worst characteristic of these TVs for me, worse than the buzzing, IR, and line bleed put together. It's not a constant thing, and a good bit of material is completely free of it, and after a while, you may not notice it less, but you may stop caring about it as much. I read that last year's U50 was free of it and hoped this year's S60 would be, but it was just as bad. I'm told the Samsung 5500 is no better than the 2013 Panasonics. Don't know about the 8500.
 
#13 ·

Quote:
Originally Posted by sawfish  /t/1307543/plasma-rainbow-effect-like-dlp#post_24058892


...I would add "Blink when you move your eyes" to that list.

Interesting, I'll try that. Thanks.
Quote:
...I'm told the Samsung 5500 is no better than the 2013 Panasonics. Don't know about the 8500.

I'm also curious if the 8500 has rainbows. It's too late for me to exchange, but a lot of people wrestle with the decision between the 8500 and the VT/ZTs, so it would be good information to contribute. With that in mind, I've tried to induce rainbows on the 8500 at my local best buy, but it is so difficult to do in a showroom that I just couldn't draw any valuable conclusion, like whether it is more prone or less prone than the pannys.
 
#14 ·

Quote:
Originally Posted by sooke  /t/1307543/plasma-rainbow-effect-like-dlp#post_24060819


I'm also curious if the 8500 has rainbows. It's too late for me to exchange, but a lot of people wrestle with the decision between the 8500 and the VT/ZTs, so it would be good information to contribute. With that in mind, I've tried to induce rainbows on the 8500 at my local best buy, but it is so difficult to do in a showroom that I just couldn't draw any valuable conclusion, like whether it is more prone or less prone than the pannys.

I've never been able to see rainbows in a showroom. It's a combination of lighting, settings, and source material. You could try bringing in some problem material on a thumb drive, ask for a remote control, and at the least, choose a standard mode with the Color Temperature at Warm 2, but who wants to explain all that to a salesman who just looked at you like you're nuts when you asked about plasmas buzzing?
 
#15 ·
Well I'm glad to hear it happens with the ZT60 as well, I almost had to upgrade. I set up a ZT60 in one of my company's conference rooms and haven't noticed it as much, but I really haven't spent that much time with it.


The strange thing is I've owned plasmas for years and have never noticed this rainbow effect before. I currently own 8th and 9th gen Pioneer Kuro plasmas and have never experienced the issue. I've also owned various Panny plasmas over the years and my parents have 2011 and 2012 Panasonics and I've never noticed on theirs either.


Like others say it's mostly when I let my eyes wander, usually when working on a laptop and looking back and forth between the laptop and TV. Oh well, I guess nothing is perfect...
 
#17 ·
Just got a Panasonic 65VT60 and clearly see rainbows, especially (as mentioned) for bright objects on a dark background, and in particular sub-titles will do it. As soon as I move my eyes quickly; colorful rainbows... I can live with it, once I get caught up in a movie I tend to forget about it and stop looking for it (or maybe my eyes don't move as much). I find it somewhat odd that plasma manufacturers haven't addressed it by either using phosphors that have somewhat longer duration phosphorescence (so subsequent images 'fuse' together), or drive the colors simultaneously, avoiding the creation of rainbows altogether. Guess there are solid technical reasons why this can't be helped.


I also see (what looks like) 60Hz strobing on bright scenes, this is actually more distracting than the rainbows and it's visible even when the eyes don't move. Much like the strobing of old-style fluorescent bulbs before the industry switched to much higher frequency ballasts.


My previous TV was a Sony GWII (rear-projection LCD), which had none of this and produced silky-smooth motion. Maybe that is why it's so glaringly obviously now on the plasma.


Still, what a jaw-dropping picture! I'll live with these (fairly minor IMO) imperfections; movies and other HD content have never looked so good! Also love the 3D capabilities of this TV; Avatar and The Hobbit are just stunning!


-RoB-
 
#18 ·
I mentioned in the other rainbow thread that I see them al the time on my ST60. As soon as it was delivered and it was turned on the first time I saw the first rainbow flash. Hard to explain what it's like but the closest I can think of is when you get knocked in the head and see stars except instead of white it's red, green, and blue.


It doesn't really bother me but still surprises me when it happens.
 
#19 ·
Yesterday I noticed something noteworthy about the rainbow effect on my ST60: the issue is less pronounced when the source is coming through something other than HDMI. To test this, I popped the Psycho DVD into my Blu-ray player. Rainbows were present. Then I put the same DVD in my old DVD player (output via composite cables) and the rainbows were nearly absent. There was a hint of a "flash" occasionally, but they weren't rainbows and thus barely noticeable. Then I did the same experiment with the Sin City DVD. This time I did see rainbows through the DVD player, but they were much more subtle.


Similarly, I notice the effect less when watching over the air TV, Youtube, Netflix, and other non-HDMI sources. I see the rainbows, but they're much less noticeable.
 
#20 ·
YMMV and all.


I can see phosphor lag. Quite clearly in fact. I saw it when I bought my first plasma television, a Panasonic professional monitor, back in 2005. But after some months of use I realized I didn't see it any longer. Then, some time later, I came across a lot of talk about the phosphor lag, the white/green trail to certain moving colours, or to the entire screen with a moving camera image, and I remembered what I saw when I first turned on my plasma. I watched a video that demonstrated phosphor lag. I immediately went to my plasma to observe this, and there it was again. Could see it plain as day. I started to get upset about this, but the news came on, and I watched the weather reports, some disaster stuff, etc. And I noticed that I wasn't noticing the phosphor trails/lag anymore. See a pattern here?


I can see phosphor lag as clearly as anything, but I can also view and enjoy my plasma televisions normally. In other words, I've found that when I am looking for phosphor lag, I see it. When I'm just trying to watch television, I don't see it because I'm too busy watching whatever, rather than focusing on the flaw. Psychological? Seems so. Perhaps I was scrutinizing the image more closely when I got my first plasma, and later just relaxed and enjoyed the thing and my observance of it washed away. Maybe it's a matter of focus. Whatever the reason, even today, I can see phosphor trails, but only when I'm looking for them.
 
#21 ·

Quote:
Originally Posted by LiquidSnake  /t/1307543/plasma-rainbow-effect-like-dlp#post_24123618


YMMV and all.


I can see phosphor lag. Quite clearly in fact. I saw it when I bought my first plasma television, a Panasonic professional monitor, back in 2005. But after some months of use I realized I didn't see it any longer. Then, some time later, I came across a lot of talk about the phosphor lag, the white/green trail to certain moving colours, or to the entire screen with a moving camera image, and I remembered what I saw when I first turned on my plasma. I watched a video that demonstrated phosphor lag. I immediately went to my plasma to observe this, and there it was again. Could see it plain as day. I started to get upset about this, but the news came on, and I watched the weather reports, some disaster stuff, etc. And I noticed that I wasn't noticing the phosphor trails/lag anymore. See a pattern here?


I can see phosphor lag as clearly as anything, but I can also view and enjoy my plasma televisions normally. In other words, I've found that when I am looking for phosphor lag, I see it. When I'm just trying to watch television, I don't see it because I'm too busy watching whatever, rather than focusing on the flaw. Psychological? Seems so. Perhaps I was scrutinizing the image more closely when I got my first plasma, and later just relaxed and enjoyed the thing and my observance of it washed away. Maybe it's a matter of focus. Whatever the reason, even today, I can see phosphor trails, but only when I'm looking for them.

As discussed earlier in the thread, your phosphor trails are a different problem, and it's not what we've been talking about. In scenes that produce the rainbow flashes, the only way not to see them is to keep your gaze fixed on the same part of the screen (or for me, at least, the same moving object). The instant I move my focus while keeping my eyes open, the rainbows appear, and this is true for a paused program.


I've got over 2000 hours on my set now, and it hasn't abated. It bothers me a little less, I think because I've learned to keep a steadier gaze and time my blinks better. (How ridiculous is that?) That said, last night I changed my guitar strings while The Godfather was on AMC. Looking back and forth between the guitar and TV was rainbows galore. I guess it will always be like this. There is nothing psychological about it. I never saw this on CRTs or LCDs, and I continue not to see it on LCDs (don't have any CRTs, but I have to think they would continue to be rainbow-free). It's a physical effect, just another one of the many flaws in plasma techology. Too bad LCD can't get black levels down and achieve decent uniformity without resorting to various dimming schemes that IME always produce brightness fluctuations that are even more offensive, not to mention, the black levels are more or less fake depending on the size of the dimming zones.
 
#24 ·
I have a TC-P50S2 since 2010. My first plasma. Ever since powering it up I've seen the phosphor trails/rainbow effect. It's really the same thing, as your eyes are seeing the difference between the R-G-B triggering/firing. You move your eyes, you see additional colour, same thing.


If some people see it, it's there. Don't dismiss the phosphor lag/rainbow effect. Just because YOU can't see it doesn't mean it doesn't exist. For the fact that it DOES exist reduces the quality of ALL display technology that has this problem, IMO. Me, I love the plasma technology theory. But the FACT that it's not displaying images in a PURE fashion really discourages me from recommending plasma technology to anyone. I don't even recommend this to family.


So if you can't see the problem, now your vision needs to be examined. What exactly are YOU seeing? How can YOU see a clear and precise image flowing across the screen when in FACT it's not really cleanly moving across the screen. YOUR eyes are really the problem. You shouldn't condemn us who see it how it is! FLAWED!


This really sticks out with lower quality content. Especially when I watched Sanctuary. It seems more prevalent in 720p or lower quality. 1080i/p content seems hard to find the issue, even though it's there when I really try to see it . So it seems, of course, it's something with the timing of the phosphors. Higher content needs faster phosphors. Lower content reduces the display/flicker/Hz/phosphors.


If you want a test DVD to take to stores to see their displays, find a video with a white box that moves left to right. That's it, that's all you need. A white box that moves left to right. Follow your eyes on the box, and you'll see the phosphor lag/rainbow effect. My wife says she doesn't see this issue. But when I played a video and told her to watch the box as it moves side to side, she saw it. Maybe that's the wife-factor on HD TV displays? :/


I go to my brother's house who has an LCD display, and his screen just displays better. Movement is more clear, more fluid/sharp. Of course there's no phosphor lag/rainbow effect which makes his display better. As long as he doesn't enable that "feature" 240Hz crap that makes it look like a soap opera.


So remember, just because you don't see it doesn't mean it's not there!

 
#25 ·
I just couldn't get used to the mega rainbows I was getting from this year's VT60 and ZT60 so they went back to Amazon. I returned them and I ended up finding a used Elite PRO-151 locally, and I'll be much happier with that.


-Sean
 
#26 ·

Quote:
Originally Posted by sean.scott  /t/1307543/plasma-rainbow-effect-like-dlp#post_24244919


I just couldn't get used to the mega rainbows I was getting from this year's VT60 and ZT60 so they went back to Amazon. I returned them and I ended up finding a used Elite PRO-151 locally, and I'll be much happier with that.


-Sean
Oh god, plasma tech has been out for how many years now!? And they STILL can't fix this major issue!?


I thought of trying a more current model, but not now after hearing the 2013s have this plague.

One of these years I'll just have to upgrade to an LCD.
 
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