Store left my new t.v. running for 6-7 hrs at high contrast level - need I worry?

Discussion in 'Archived Threads 2001-2004' started by JasonRH, Jun 30, 2001.

  1. JasonRH

    JasonRH Second Unit

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    There was a direct view 32XBR-450 that I was going to purchase and I asked the store workers to set it up for me so I could try it out in-store before I bought it. They did this at closing one night and I went in the next day to try it out and found it had been on for several hours (7 or so) at the horrible factory setting with high contrast. Could this have caused any damage to the phosphors? I don't believe there was ever any static images or text on the screen so that's not an issue. What would be some of the noticeable effects if there was any damage? How long does it usually take for high contrast levels to show any effects on the picture, or is it just the life of the tube that is effected by high contrast levels? As you can see I don't know much about this issue. Any help would be appreciated.
    Please let me know if this is an actual concern I should have or if I'm totally off base.
    Thanks a lot.
     
  2. Ryan Pream

    Ryan Pream Stunt Coordinator

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    I wouldn't expect that to be a problem for a RPTV, so definantly not a problem for a direct view TV. It's almost impossible to burn a pattern on a direct view TV. Over the years it will dim but definantly not in 6 hours.
    Ryan
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  3. JasonRH

    JasonRH Second Unit

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    Thanks Ryan, that makes me feel a lot better. Some people seem really paranoid about possible burn-in and emphatically emphasize that you should turn contrast way down IMMEDIATELY apon turning your set on to avoid possible damage. I guess I got paranoid reading the posts of those people. Having the light output high for a handful of hours shouldn't be a problem in today's sets.
    Any other opinions are still welcome, as I don't understand the process behind possible high contrast level damage.
     
  4. Ryan Pream

    Ryan Pream Stunt Coordinator

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    My understanding of burn in:
    All of the CRT based displays are based on electrons hitting phoshpers and emmiting photons your eyes can see. Over time these phoshpers stop emmiting as many photons and thus look dimmer. The more the phosphers are used the faster they will grow dim.
    So if you have one area of the screen that constantly has brighter material, it will grow dimmer faster. Letterbox programs could burn a pattern in, since on part of the screen the phosphers are not being used. If you displayed solid white on a screen burned in by watching letterbox programming, the top and bottom sections would appear brighter.
    The 3 main types of CRT displays are Front Projection, Rear Projection, and Direct View. Front projection's phosphers have to be much brighter then rear projection so they are the most susceptible to burn in. Rear projections phosphers are much brighter then direct views so they are in the middle. Direct views have the phospers over the entire screen surface so the phosphers don't have to work very hard. Ever see a modern computer monitor with burn in? It doesn't happen.
    Unless you have a CRT projector I don't think burn in is much of an issue any more.
    Ryan
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  5. ThomasL

    ThomasL Supporting Actor

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    Ryan and Jason, burn in can happen...in fact, I just saw it on a modern computer monitor a few weeks ago. A dialog box had popped up and apparently been left on the screen for a loooong time at high contrast levels, since now, it's there permanently - faint but annoyingly noticeable by all who've looked. I don't know the exact physics behind burn in but what it seems to me that can happen is that the phosphors become permanently altered by the intense bombardment of electrons for a prolonged time - why or exactly what is occuring, I really don't know but it can happen apparently, even on modern day computer monitors and direct view tvs.
    Jason, if there were no static images left on the screen for 7 hours straight at max contrast, then you should have nothing to worry about, and running at max contrast for that long shouldn't lower the lifetime of the phosphors in any measureable way.
    hope this helps,
    --tom
     
  6. Jeff D.

    Jeff D. Supporting Actor

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    First off, burn-in can occur with ANY type of CRT device - its the nature of the beast. FPTV and RPTV units are more susceptible since their CRTs are driven a lot harder to provide adequate light output.
    Having said that, burn-in can occur on a direct view as well. The rules are the same: keep the Contrast set to an appropriate level and don't have static images on the screen for extended periods of time.
    Now, in regards to the specific question. Was this procedure good for the phosphours? Absolutely not. Will there be any visible damage? As long as there were no static images, I don't think so.
    Running phosphours at maximum Contrast levels is never good, for any length of time (Video Essentials even points out that a period as short as 30 seconds can cause permanent damage with some test patterns). Whether the effect will be visible or not is another question.
    ____
    Jeff
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    "They're coming to get you Barbara..."
     
  7. JasonRH

    JasonRH Second Unit

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    thanks all.
    I'm quite sure there were no static images so I'm feeling better about it. Thanks for all the info.
    If there were static images on screen, how soon could burn-in be expected?
     
  8. ThomasL

    ThomasL Supporting Actor

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    Jason, I'm not a burn in expert but I think you should see the effects of burn in rather immediately. Just turn on the tv and bring up a blank screen somehow. Any burned in image should be visible - perhaps faintly. I don't think you have anything to worry about though, given what you've said. I recommend getting the Avia dvd and calibrating your user settings. You should be able to properly set your white level (contrast) using the Avia test patterns.
    The level of contrast the set has will also determine the risk of burn in. My Toshiba 27A40 has its contrast set to 53 percent and it's not being driven hard at all. On the other hand, the Toshiba 20AF41 I have is really producing a high contrast picture. I have its contrast set to 23 percent (both calibrated with Avia). If all of the new line of Toshiba flat screens behave like this, then I'd say they're definitely at risk of burn in if you left it at the factory defaults with a test pattern on the screen for a long time (And what were they thinking putting a factory reset button on the remote? I wish I could physically remove it [​IMG] )
    cheers,
    --tom
     
  9. Ryan Pream

    Ryan Pream Stunt Coordinator

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    I think you guys are way over exagerating the burn in danger. If it was so easy everyone would have burn in from watching letterbox movies. How many computer monitors have a burnt in "Start" button? I've had my computer monitor for 5 years without a screensaver at 100% contrast and it has no burn in at all. I work in an IT department and none of our monitors have burn in. Most of these show the exact screen pattern every day and some of the monitors are 10 years old. I have a hard time believing a pop up menu could burn in over a period less then many months. Granted TV's may be more susceptible.
    Burn in was much more an issue in yesterday's CRT devices then todays. How many people on this forum have actually seen a burn in pattern on a modern direct view TV? The manufacturers aren't so stupid that they would give factory setting's that cause immediate damage.
    Ryan
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  10. JasonRH

    JasonRH Second Unit

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    Thomas L,
    I agree - remove that stupid reset button on the remote. I've calibrated my parents' tv set and constantly find it back to factory defaults at MAX contrast level. I refuse to keep pulling out the Avia disc! It too is a Toshiba, though an older model.
    Ryan,
    I tend to agree with you with the little that I know, just thought I'd get some feedback about the issue since I'm spending $3000 on a tv set that should not have been turned on until I got it home. Most replies on this topic seem to support your view that, in my case at least, there should be no problem with what was done. I feel better about that. I wasn't really worried about static image burn-in on the screen, I just thought maybe there were other effects on the phospors that could degrade the overall picture quality or performance of the set. Are the other possible effects on performance?
    Thanks again everyone.
     
  11. ThomasL

    ThomasL Supporting Actor

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    Jason, I don't think there is anything else you really need to worry about given the relatively short time we're talking about. The main goal with setting the contrast is just not to overdrive the internal electronics of the set. The Avia Contrast test pattern is a good way to make sure the contrast level is not causing "blooming" to occur. And as for the reset button, yeah, I really don't know who were sitting in the marketing research meeting going "consumers are demanding a reset button on their remotes" Perhaps they put it there so it would be easy for Best Buy employees to reset the picture back to factory defaults of max contrast, etc. at the end of each working day [​IMG]
    Ryan, I also manage an IT dept and while I pretty much agree with you, I have seen it with my own eyes, whether it's just defective monitors or monitors with extraordinarily high contrast levels, I don't know, but it has happened a few times over the past decade that I've been in the business. Of course, in my line of work, I've found that the users are capable of almost limitless destruction so nothing surprises me (whether it's burned in images on monitors or Diet Coke stained keyboards and disk drives). [​IMG]
    cheers,
    --tom
     
  12. Ryan Pream

    Ryan Pream Stunt Coordinator

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    quote: I've found that the users are capable of almost limitless destruction so nothing surprises me [/quote]
    I definantly agree with you there! The only time I remember seeing burn in is on the old dumb terminal displays. It's pretty common to see those with the login screened burned in. It's definantly better to be safe then sorry though. Lowering the contrast also makes the picture look MUCH better.
    Ryan
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