Plasma Questions

[dave_k]

Hi All,

Couple of questions about plasmas (I've a Panasonic).

When i switch off there is and obvious 'ghost' of the last image. How does a plasma manage to produce blacks when it is switched on but yet when the power is off the pixels glow pale grey?

Also is there a way of powering off a plasma to minimise this effect?

Thanks in advance,

Dave

 

[Anonymous]

I'm sure more qualified answers will be on their way but as I understand it what you are seeing is temporary image retention, not to be confused with permenant screen burn. This I believe is a trait of all phosphor based TV's. I have the same thing with my Panasonic V10 but have to get my nose to the screen to see it. To be honest I started getting quite paranoid about it but it's never caused any problems with picture quality and after a couple of minutes of moving images it goes away.

If its of any use my plasma has just gone through 300 hrs of use and its nowhere near as obvioud as it was when new, just don't use really high contrast levels for the first 200hrs or so.

 

[Anonymous]

I have a panasonic v10 and I get the same thing, especially when I turn the tv off and the room is dark, but it does subside after a few minutes after switching off. My contrast levels are fairly high now (maybe 60%) as I'm using the tv's THX mode, but I used the Cinema setting with very low (30%) contrast for the first 200hrs or so.

drjeep38,

do use your v10 on THX and, if so, do you keep the contrast at that level? I think THX has the contrast set up quite high, but I don't want to mess with it. Is 60% contrast considered too high for plasmas?

I used to be quite paranoid too - though much less so now, after much posting on this site. After watching a film with a 2.35:1 aspect ratio, I always leave a full screen tv channel on for about 15 minutes, as I can usually still see the black bars on a black screen immediately afterwards, but watching some full screen content clears this up.

 

[Anonymous]

hmtb - I only really use the THX mode for movies and I've left the THX settings as they are as I believed that was the best calibration possible without a major tinker with the service menu (and I'm going nowhere near that!), plus it seems to be better for films anyway. I use the normal mode for daytime viewing with the contrast also around 60-65% and the brightness up a notch or two and set to warm. Cinema mode I use in the evening, again the contrast is about 60% but the brightness and colour is down a notch or two.

I agree with leaving a full screen image on for a few minutes to clear any black bars but it small price to pay for the picture quality. I've no idea if 60% contrast for plasma is considered high but I wouldn't have thought it's excessive.

 

[Anonymous]

I was so close to buying a plasma guys, and now I'm not so sure lol. I'm a bit paranoid about this sort of thing my tv permanently!

 

[Andrew Everard]

We're talking temporary image retention here, not screen burn. Modern plasmas are all but impervious to screen burn, and employ extra strategies, such as pixel orbiters, to ensure even long-term static images don't create a problem

 

[Anonymous]

genfish, I wouldn't let these comments influence your purchasing decision. I'm sure this topic has been covered a million times before on these forums and it really is no big deal and and far as I can tell any image retention is certainly not permanent. As I say, I have to get my nose right up to my 50" screen to even see any retention, and even then its very very faint in a completely dark room. From a couple of feet away it can't be seen at all.

I only looked for this trait on the TV after reading about it on forum sites, if I'd not read it I would never have noticed it.

 

[Anonymous]

I know its been covered a lot, its probably just me having OCD or something

So after a letterboxed movie, is it still best to run the tv full screen for a while, or is that just a precautionary measure you are taking?

 

[Andrew Everard]

No, no need to do that either

 

[Anonymous]

andrew , do you know if whfi will be reviewing a samsung b850 plasma this year ?? ta..

 

[Anonymous]

Purely precautionary. I don't even know where I got that little nugget of wisdom from, but it's become a bit of a habit. Glad to know that it's not necessary though.

I've fallen asleep watching my tv before, and woken up 6 hours later having left a static image onscreen (blu ray player switched itself off), and I didn't get any image retention or screen burn.

I wouldn't worry too much (although I did at first).

 

[Andrew Everard]

maxflinn:andrew , do you know if whfi will be reviewing a samsung b850 plasma this year ?? ta..

AFAICS it's not on any advance contents lists yet.

 

[Anonymous]

ta , strange that samsung have not sent you one , good tv by all accounts , oh well , they must have their reasons ...

 

[dave_k]

Thanks for all the responses folks, you've put my mind at rest

 

[TKratz]

maxflinn:ta , strange that samsung have not sent you one , good tv by all accounts , oh well , they must have their reasons ...

Agree, a lot of places this is described as the best plasma screen (or any screen) on the market right now (excluding the Pioneer's) in sharp competition with Panasonic V10