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25ms vs 18ms

Discussion in 'LCD & LED LCD TVs' started by deadpcagain, Mar 29, 2005.

  1. deadpcagain

    deadpcagain
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    Hi all,

    Theres a lot of talk about the difference between 25ms response time and 18ms response time, im using a 25ms 17" lcd tft and have never noticed any problems when playing high speed games etc and im currently looking at a 32" lcd with 25ms.

    My question is this, can the human eye really see the difference of 7ms between 2 screens, and is the difference magnified greatly when its on a much larger screen ?

    Cheers

    Mick
     
  2. VurtHed

    VurtHed
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    From what I've read, I think that it depends on the screen and the person viewing it. Different screens with the same officially quoted response time can have varying levels of display artifacts with games. I don't know if this is due to inaccuracies in measuring the response times, or that some screens have other technology that minimises the effect. I have also read that some people's eyes pick up the artifacts easier than others.
     
  3. ianh64

    ianh64
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    A European signal is 50 frames/fields per second (progressive/interlaced). That equates to 20ms. NTSC is 60Hz, which is approx 16ms.

    So if you have a response rate > 20ms, you will definately have an image that is present across 2 frames/fields. How visible this will depend on alot of things.

    This is not saying that 18ms, 16ms, 14ms, 12ms, 8ms etc etc is much better. The ideal is 0ms. But at least the display electronics have a fighting chance to avoid the image lagging between frames.

    -Ian
     
  4. deadpcagain

    deadpcagain
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    Actually, I thought European PAL was 25 fps for realtime ?
     
  5. ianh64

    ianh64
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    Interlaced PAL is 25 full frames per second, 50 fields per second
    Progressive is 50 full frames per second

    LCD displays are progressive scan, irrespective of what you feed them. They will internally deinterlace to 50 or 60 frames per second.
     
  6. jimsan

    jimsan
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    Just thought I'd pop this in here.......

    Viewsonic have produced a monitor with 4ms PR......That'll just about do it!

    Jimmy
     
  7. loz

    loz
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    theres also the issue of lack of consistency in how response times are measured or reported.
    One vendors 25ms is another vendors 18ms.
     
  8. garrad

    garrad
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    The responce time has nothing to do with frame rate of playback. The responce is the time to go from a white pixel to a black pixel and back to a white pixel. (or maybe the other way around) It's the full responce. You have an up time and a down time.

    Usually only in fast changes will this cause a problem, lots of changes in brightness and large colour differences. This is why the responce time of an LCD TV is far more important for computer games than it is for movies.
     
  9. MattTheCat

    MattTheCat
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    The response times are almost meaningless. You need to see the graph for the colour spectrum to get a better idea of how well it will perform in that respect. www.tomshardware.com has very good reviews for computer LCD screens

    As a rule, I'd recommend going for a low brightness level (white level for LCDs), and a very high contrast ratio level (difference between the blackest and the whitest the display can produce). This will yield good blacks. The white level for LCDs is already far beyond what any CRT can do, and isn't needed.
     

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