57U
10-21-2003, 05:37 PM
Burn in is more properly known as "uneven phosphor wear".
What causes burn in?
CRTs "wear" as they are used. If the same part of the TV is "hit" with the same image for long periods of time, it will "wear" differently from the other parts of the CRT that are being "hit" with varying images.
After a while, this results in uneven phosphor wear, or "burn in". You will be able to see the image that was 'static' on your TV - for example, a logo, a black bar, a ticker...
CRT-based Direct View TVs, CRT-based RPTVs and Plasmas are susceptible to burn in.
Burn in, can happen in as little as 6 months and is PERMANENT. It cannot be "reversed"
You can prevent burn in by not having any fixed images (like opaque logos, or tickers, etc) on the TV for extremely long periods of time. Short periods of time are perfectly acceptable. Burn in is cumulative. This means that you can't burn in an image in hours or days. It takes months, but it can happen.
TV setup also plays a major role in Burn-in. Many TVs come shipped with the default picture mode being "Vivid" or "Dynamic" - see the Digital Home FAQ What you need to do to your new HDTV (http://www.hdtvoice.com/voice/showthread.php?t=1440)
This doesn't mean that you can't watch any 4:3 HD or 2.35:1 DVDs, but that you should keep any static image to less than 15-20% of your overall viewing on a "susceptible TV". Burn in is something you should be aware of, but not paranoid about. This post is not intended to "frighten" but educate.
The order of susceptibility to burn in, from most likely to least likely, is as follows:
Plasma
CRT-based RPTVs
CRT-based Direct View TVs
LCD-based TVs (not susceptible)
LCoS-based TVs (not susceptible at all)
DLP-based TVs (not susceptible at all)
(For LCD-based RPTVs it's possible to encounter greyscale degredation under severe service - as in commercial service where the TV is on all day, on the same channel, but it's not a concern under normal home use, where the TV is not on the same channel 24/7)
Although grey bars mimic the phosphor wear of colour images, you cannot be assured that you will not see burn in, especially at the interface of the 4:3 image and the "bars". I know this from experience, on a calibrated CRT-based RPTV, after watching 4:3 almost exclusively for only 6 months. Luckily I noticed when the lines were very faint and they are now gone after several years of appropriate viewing.
Sometimes people will notice "short term image retention", especially on plasmas. This may come from watching the same channel for hours, or perhaps days. This is not burn in and should go away if you watch something different and look for it again in a day or so.
Plasmas:
Recently there has been a lot of discussion about the fact that burn in is no longer a concern on newer plasmas. This is simply not true since the phosphors do age with time and therefore, will age differently depending on what's displayed on screen. A black bar will not age phosphors at all. Therefore, if you accept that phosphors age, you must accept the possibility of burn in on new plasmas, even if the likelihood has been decreased from older plasmas since they age less rapidly. As stated above, burn in takes a long time to see - many months or a couple of years for example. Varying the programming you watch and not watching too much 4:3 programming should be fine.
If you would like to make additional contributions to this post or have corrections/clarifications, please PM me.
What causes burn in?
CRTs "wear" as they are used. If the same part of the TV is "hit" with the same image for long periods of time, it will "wear" differently from the other parts of the CRT that are being "hit" with varying images.
After a while, this results in uneven phosphor wear, or "burn in". You will be able to see the image that was 'static' on your TV - for example, a logo, a black bar, a ticker...
CRT-based Direct View TVs, CRT-based RPTVs and Plasmas are susceptible to burn in.
Burn in, can happen in as little as 6 months and is PERMANENT. It cannot be "reversed"
You can prevent burn in by not having any fixed images (like opaque logos, or tickers, etc) on the TV for extremely long periods of time. Short periods of time are perfectly acceptable. Burn in is cumulative. This means that you can't burn in an image in hours or days. It takes months, but it can happen.
TV setup also plays a major role in Burn-in. Many TVs come shipped with the default picture mode being "Vivid" or "Dynamic" - see the Digital Home FAQ What you need to do to your new HDTV (http://www.hdtvoice.com/voice/showthread.php?t=1440)
This doesn't mean that you can't watch any 4:3 HD or 2.35:1 DVDs, but that you should keep any static image to less than 15-20% of your overall viewing on a "susceptible TV". Burn in is something you should be aware of, but not paranoid about. This post is not intended to "frighten" but educate.
The order of susceptibility to burn in, from most likely to least likely, is as follows:
Plasma
CRT-based RPTVs
CRT-based Direct View TVs
LCD-based TVs (not susceptible)
LCoS-based TVs (not susceptible at all)
DLP-based TVs (not susceptible at all)
(For LCD-based RPTVs it's possible to encounter greyscale degredation under severe service - as in commercial service where the TV is on all day, on the same channel, but it's not a concern under normal home use, where the TV is not on the same channel 24/7)
Although grey bars mimic the phosphor wear of colour images, you cannot be assured that you will not see burn in, especially at the interface of the 4:3 image and the "bars". I know this from experience, on a calibrated CRT-based RPTV, after watching 4:3 almost exclusively for only 6 months. Luckily I noticed when the lines were very faint and they are now gone after several years of appropriate viewing.
Sometimes people will notice "short term image retention", especially on plasmas. This may come from watching the same channel for hours, or perhaps days. This is not burn in and should go away if you watch something different and look for it again in a day or so.
Plasmas:
Recently there has been a lot of discussion about the fact that burn in is no longer a concern on newer plasmas. This is simply not true since the phosphors do age with time and therefore, will age differently depending on what's displayed on screen. A black bar will not age phosphors at all. Therefore, if you accept that phosphors age, you must accept the possibility of burn in on new plasmas, even if the likelihood has been decreased from older plasmas since they age less rapidly. As stated above, burn in takes a long time to see - many months or a couple of years for example. Varying the programming you watch and not watching too much 4:3 programming should be fine.
If you would like to make additional contributions to this post or have corrections/clarifications, please PM me.
