It's official. I see a rainbow-like effect on every plasma. - Page 19

Plasma displays create grayscale by using a special kind of PWM (pulse-width-modulation). Unlike regular PWM plasma displays have a set number of pulses with binary widths (0,1,2,4,8,16,32,64,128..etc). To get all possible luminence levels these binary pulses are chosen in combination accordingly.

For example to get a grayscale step of 51 they would activate pulse 0,1,2,16,32 in that order. But unlike regular PWM the pulses remain time separated. For example:

sub-pixel #1: grayscale of 51 the pixel would do the following:

0 , 1 , 2 , off , off , 16 , 32 , off , off
-------------------------------------> time (16.7ms)

sub-pixel #2: grayscale of 128 the pixel would do the following

0 , off , off , off , off , off , off , off , 128
-------------------------------------> time (16.7ms)


This time seperated pulse modulation causes many motion artifacts and some color seperation as you can see in the above example. Pixel #1 is on while pixel #2 is not and visa versa.

However, I've seen some data that suggests that this is not the cause of the plasma rainbow phenomenon. Rather it is the phosphor decay differences, with green and red phosphors lasting longer than blue.

Cheers

That's my problem: Yellow streaks. I've noticed by having energy save mode on and slightly blue whites I can lessen the effect. That's of course at the cost of picture quality to a degree. If I put on sunglasses they also seem to filter the yellows a tad making me think that the Samsung with the Ultra glare filter would also help some.

I wonder if there's any reason to belive that 1080p screens would have faster phosphor decay than 768p?

This makes the most sense as an explanation for me, as I can see a similar effect with some CRT RPTV's.

Hi,

I'm wondering if anyone out there who experiences this problem has had their plasmas professionally calibrated and if it helped. I had a Runco plasma for a while that showed this problem something awful, but I believe it lessened substantially after I had it calibrated. I don't have the TV anymore so I can't be sure of how much of difference it made, but I recall thinking it almost seemed unnoticeable. Has anyone experienced a post calibration improvement in this phenomenon?

Who sits in front of their TV during normal TV watching times and waves their hand in front of their eyes. Just my opinion but if you don't go looking for problems the problems in most cases will go away. If you try to find the rainbow or "plainbow" effect in everything you see, then 9 out of 10 times your gonna find it. I install and watch all the sets mentioned in this thread everyday and the only time I've seen this is in the DLP when I look back and forth at the picture rapidly. Not doubting any one but it kind of baffles me. Have you ever thought about how you have your service set up. If 1080I maybe your seeing the ladder effect from the refresh rate vs. a rainbow. This has been a very informative thread and hopefully someone can shed some light on this for us!!!!
Just my $.02

Well, I gotta say. Now that I have had my plasma for about a month I can no longer see rainbows. I don't know if its because ive gotten used to it or if maybe the phosphor has settled down.

I could see them quite often when I first got it. Mainly while playing games. But its been a while since ive seen them.

Perhaps this is just an affect of new plasma's with fresh phosphor. Could disappear once the TV is broke in.

Just my two cents.

Oddly enough, I've made the same observation.

If you look at the history of this thread about 10 or 11 months ago, you'll see some rainbow comments from me. Now I never see them on color material and very, very rarely on B&W material.

BTW, I am very happy with my 42" Vizio...

Regards,
Scott

FYI, I see the yellow trails something fierce on the new 700u series 1080p plasmas.

After reading the entire thread I feel I need to add additional info.

I got a new Panasonic 50" 700u 1080p plasma and was completely thrilled with the look. I did some gaming, stuff like Ridge Racer 7 and it was amazing. The other day I popped Gears of War for 360 in, and the whole screen was filled with yellow blurs when I moved around in the game. I hadn't heard of this type thing with plasmas, and I've never seen DLP rainbows or any similar artifact with my Pioneer Elite RPCRT.

THEN I did some google searches that led me to this thread.

Now that the new 8th gen Pio's are out with a different cell structure, have any of you with the yellow streak issue checked them out to see if the new electrode and lower charge changes the artifact?

I suffer from this and would love to know more. The Pio is different than all other plasmas right now, so it might be better for us... (or worse)

Apparently not everyone sees the yellow streaks/rainbows on plasmas.

Then there are plasma fanboys who see them, but deny.

These artifacts originate because different response times and latency of the RGB phosphors used in plasma.

They are chemically different phosphors than those used in CRT, and their response times may be less in synch with each other than the CRT phosphors.

They can't be that difficult to spot, my wife can even see them without difficulty. I popped in Sin City and it was a mess. I should note that she can't even readily tell the difference between a regular DVD and HDTV.

The funniest part, I went to return the TV to BB over the weekend and the salesperson not only knew of the issue, he was explaining it to his coworkers. I was floored to find someone at a common retail outlet that was familiar with this.

I was sad returning the 700u because it's otherwise so stunning. Between the dozen dead pixels and the green trails it wasn't a keeper though.

lol, interesting choice of wording, "apparently not everyone". The fact of the matter is that only a distinct minority of people are afflicted by this phenomenom. Enough to justify a dedicated thread perhaps, but insignificant in the grand scheme of things. For example, whenever I read through the sticky 'you've just bought a plasma, tell us about it' thread, very very rarely have I encountered anyone complaining about this.

Now if there actually exists people who do "see them, but deny", the most logical explanation for that would be that the picture quality pros outweigh the cons by a significant enough margin, or, the trailing simply isn't all that bothersome to them, to the point of necessitating they make a panel change because of it (assuming they already own one).

Your theory that some choose to see but deny due to a kind of fanboy allegiance is a much less plausible conclusion to draw. If it's a real irritant to their viewing experience, and yet choose to defend regardless because they've apparently developed some bizarre anthropomorphic relationship with their plasma or the plasma category in general, well, that would be very strange indeed. But not very likely, at least, not anywhere as likely as the first scenario I've described above. I just don't think you are capable of being dispassionately neutral on this subject. In fact, whenever I encounter one of your posts anywhere on the forum, my first thought is always "oh, here is 'plasma-trails-cranky-guy'.

Look, I understand how much of a bummer it would be to find oneself amongst those unexpectedly afflicted by this green/yellow-trailing or lagging problem, especially if you've laid money down and now your left with a financial loss or return hassle to deal with. But lashing out at others for not "admitting the truth!" isn't the most reasonable way of responding to the situation.


Few people complain about it, so it must be difficult to see for most. Just because you and your wife just so happen to see it doesn't support a conclusion that it should be a common viewable occurence for many. Your situation is just a slightly odd luck of the draw, no more significant than a coin toss where "heads" come up 6 times in a row when a result of "3 heads, 3 tails", "4 heads, 2 tails" or even "5 heads, 1 tail", would seem more likely. It happens. I wouldn't attach too much significance to it.

Any streak sensitive users checked the new Pioneer Kuro 5080's yet? I'm really eager to know how they do with phosphor decay rates...

I can report on the 4280 on Wednesday...maybe Thursday, when mine gets delivered.
I can see them fairly easily...but it doesn't destroy my viewing like DLP color separation.

thanks vigga. The easiest test I found was using http://www.tvblink.com/i_down.html just download this small file burn it and run the tests with the scrolling white bar against black backdrop. There is a test for horizontal and vertical panning. Ive tried this test on most current plasma and they all had green or yellow streaking.

Perhaps a shill, not a fanboy is a better choice of words.

Regarding the green phosphor lag - there are US Patents from Thomson describing this phenomenon and how to alleviate it.

It is really quite simple - the green phosphor decays slower than the other two.

You can see the greenish/yellow trails in certain motion scenes.

Admittedly, a very high percentage of plasma owners are *not* critical viewers, so they don't notice them.

God bless'em.

God bless ya. I can't wait to hear your results!

Can you report anything on this yet? I hope you're enjoying the new HDTV!

Sometimes you are so excited about something you won't see it until couple days to weeks later. THis is normal and nothing to be ashamed of. of cource, there could be a problem.

crt have 58 years of experience compared to 8 for plasmas. of course plasmas have glitches.

Have you considered getting your eyes checked? Abnormal Color Vision can be caused by a number of difference conditions including Macular Edema, Corneal Edema, and Central serous Chorioretinopathy. The conditions are often highlighted by strobing lights or high contrast motion.

I have this issue... my wife sees it too, my friend can see it... I can photograph it. I can videotape it... The Gears of War photos on the web i've seen look exactly like it.

Dunno about you , but I'm thinking it's real.

TO SORKA and ALL OTHER PEOPLE WHO CONTINUE TO QUESTION THIS PROBLEM. If you have a plasma download the small file i posted a few posts up. There is a test with a scrolling white bar over a black background. YOU WILL SEE the trailing guranteed. This is not some eye defect and it's not really that hard to see. Some people like myself and wojtek can see it easily. If anything I think people with above average vision would pick it up faster. (I have 20/10 vision which is very good) BTW, this effect is much more noticable with video games. With regular programing I don't find it to be much of a problem. But, for gamers like me it's very annoying.

Anyway run the test on a plasma before you open your mouth about this being due eye defects or as some people in this thread have hinted at, brain defects. If you don't see the green/yellow/blue trails following of predceding the white bar then I'll buy you a case of beer.

When are we gonna get some 8g reports? Hoping to GOD that the 8g somehow does not suffer from the trails or Ill be waiting for LED LCD.

It is definitely real, no question. But I don't see it at all. And I know why.

The fact that everyone can see it on that youtube video should give a clue as to why when looking at a plasma screen "MOST" don't see it and some do.

Wether you see it or not has nothing to do with how sharp your vision is but rather how fast your retina is. Not everyone has the same eye persistance and the people with long persistance will be more susceptible to motion artifacts and color seperation artifacts.

And as for the camera being able to capture it? Film or CCD cameras have long persistance times as the CCD or film collects information over the entire frame capture time period. If you are taking a video of a plasma and the plasma frame display rate is not in sync with the cameras CCD capture rate it will capture shadows and trails where objects have moved. And in the case of plasma those shadows and trails will be colored as the phosphor decay times are different.

Think about it: if the camera shutter is open when the plasma display changes frames, the cameras CCD will capture a moving object at two locations and produce color artifacts as the individual RGB decay times are different.

Touchy are we?

Seriously, a video or photo is going to show what you're observing because you're likely using a capture device that has a ccd. Although they've gotten better over the years, they're not as good as most human eyes. Some people have cones that take a while to discharge. If you're one of these people, then it just means that you're retina is slow to to respond and you'll see what you're describing. It has nothing to do with sharpness. My corrected vision is 20/15.

Wow. People are slow around here. I said you should download the test dvd and run it on your plasma. The test with the white scrolling line against the black background DOES NOT have any trails in the source. If you run the test on a CRT or LCD their IS NO colour trailing before or after the white scrolling bar. There is only trailing on the plasma. So this is not some effect captured by some video camera. This is the plasma giving you trails in real time. Try running the test and then we can talk. Does this make sense to you, or do I have to explain in more detail. Do you know what a test/calibration dvd is?

So your theory is that my eyes respond slowly, but only to the green phosphor? But my eyes work fine for the red and blue?

If my eyes perceive no green trail issue with my Pioneer RPTV using the same source for a test, how is that explained? Why would my cones discharge fine when viewing CRT phosphor but not plasma phosphor?

Cones have peak color sensitivities at 440nm (blue), 545nm (yellow-green), and 580nm (orange). The discharge rate is slower at these peak values. If your cones are slow to discharge in general, you'll probably notice this most in the yellow-green range.

I can't tell you why you don't see it on a CRT display. I could go on and theorize about possible reasons but I'm not an expert so I'd be guessing at this point. My main point is that just because you don't see it on a CRT doesn't necessarily mean the effect is real on the plasma. The differences just may make it easier for your eye to see it on plasma if you have an Abnormal Color Vision disease.

Wow. People are indeed slow around here. I don't think anyone is making an argument against plasmas manifesting this "trailing" phenomenom. Nobody, in the last page or two at least, is even addressing that question (edit: well, maybe sorka is in his post just above mine).

What we are mainly addressing is the notion that everyone or even a substantial number of viewers will experience it. The evidence seems pretty clear on THIS question. It's either not noticable at all to most people, or if they do see it, it's not bothersome to them. At least not to reach the point where they begin obsessing over it or the problem becomes so troublesome to the extent that they can no longer enjoy their picture. A minority of people are this latter camp, congregating in this thread, for example. For those of you in this boat, yes, I can absolutely appreciate why you would be frustrated and wishing for a plasma that could somehow resolve or compensate for it.

What I don't get is why some of you feel that you must convince the non-trail-seeing majority that they damn well should be seeing what you are seeing! It's almost as if you wouldn't feel so alone or something, if only you could recruit more people to your optical circumstance. Not unlike those who can see and be highly irritated by the color wheel on DLP panels, the only thing you can do at this point is to choose another panel technology or hope for a future adaptation to the current plasma manuf. model.

Or, as sorka has suggested, perhaps a visual condition may be effecting your specific reason for being more susceptable to see the lagging/trailing. I don't think he necessarily meant to say that EVERYONE who sees them must have some visual deformity which needs correctly. For a select few of you, a solution MIGHT be found by investigating along this path (sorka please correct me if I'm misreading your intent).

Perhaps the new 8th gen Pioneer models will somehow correct for this, given their sophisticated new "adaptive motion" compensation. My sense is that this new feature of theirs won't address this particular issue, unfortunately. Time will tell, as the new Pios begin showing up in retailers near you, so you can test them out for yourselves.

People keep talking about phoshphor lag, trails, news flash-these are not crt's.

Dlp= flashing rainbow effect in dark scenes. Even all black screen.

Plasma=no rainbow effect in dark scenes, wont show the effect on a all black screen, but shows flashes with bright scenes especially with alot of white in them. It's a constant color flashing type effect, no 'trailing'.