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Disadvatages of LCD?

Discussion in 'LCD & LED LCD TVs' started by yan, Oct 4, 2005.

  1. yan

    yan
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    I would like to hear from all the LCD owners particulalry those who have larger screens.

    I have the Pioneer 503HDE and am considering changing it having seen some new LCD models with which I was very impressed. How relevant are the issues below to todays LCDs?

    Delay problem. I have been told this is something that cannot be overcome as it is inherent to the technology. I know there are newer LCD panels that have lower m/s times but there still is a delay? I have heard this is particularly noticeable on models above 35 inches.

    I guess the delay issue is a problem which will never be solved as it the nature of the beast. I have seen a thread in the forum asking about delay times so this is obvioulsy still an issue?

    Black levels: Most , if not all, LCD tv's tend to have difficulty going fully "black" due to the backlight which shines through the lcd panels. Blacks tend to have a very very dark grey. Is this still an issue?

    Field Of Vision: When you look straight on the picture it looks great, as you move to either side the picture quality diminishes and eventually disappears. Some LCD tv makers claim up to 170 degrees field of view. I have been told this is a a complete lie.

    Digital looking picture: Many LCD screens tend to have a "digital look " to the image and therefore don't seem to reproduce colors naturally. I saw this on the latest 42 inch Phillips when I was viewing them, it had almost a blue tint to the picture.

    So what I would like to know is have these problems been solved or to what extent do they still exist?

    Yan
     
  2. alefsin

    alefsin
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    I'm not an expert in LCD technology so I just try to tell you what I know:

    1- Delay: There are two things here. One problem is the delay caused by the digital video processing/enhancement circuits that would make a delay in the video pipeline and make the picture and audio out of sync. This, of course, has nothing to do with LCD technology as even some CRTs have this problem (look at some older Philips TVs). You can always fix this in a good A/V receiver by inserting a delay in the audio. The other "delay" that may interest you is what is actually called the "Response time" and that is the time it takes for the panel to change intensity of light for each pixel. This time is in the order of milliseconds and depends on the LCD technology used. However, for TV applications (which is relatively slow refreshing) and today's technology, the top of the line LCDs have such a low response time that are virtually non-visible even for the fastest moving scenes.

    2- Black level: This the main thing you should consider when comparing top of the line LCDs as this is the key issue that has not yet been fully addressed. Black level on the top of the line, big LCDs is yet a problem as it tends to be higher than the CRT or Plasma displays. For the smaller LCDs, however, there are already panels that even outshine CRTs. Personally, I don't watch TV in a completely dark room anyway and find current black level of the better, big LCD panel quite good (my LCD is surely better than my old 28" CRT!).

    3- Field of Vision: It depends on the LCD technology (TN, MVA, IPS, etc.). With some technologies, 170 degrees is quite possible. Take a look at Hitachi 32LD7200. It is uses an IPS panel and gives you 170 degrees field of view.

    4- Digital looking picture: Well, I don't know exactly what you mean by this one. The fact is that some panels can produce colors in just 6 bits per RGB channel while some others can do 8 bits per RGB channel. With 6 bits per RGB, you'll have "only" a 18 bits color space or nearly 262,000 colors while with a full 24 bits color space, you can have up to 16 million colors. With lower number of the colors, you may some banding effect on smooth color transitions. Other than that, there is possibility of noise and/or digital process artifacts that depends on the quality of the DSP technology used by the panel and can vary a lot between different ranges of the displays.

    My conclusion is that, today, good LCD TVs are at least as good as any other technologies regarding point 1, 3 and 4 and only at the point 2, the black level they need more improvements. However, for many users (including myself) black levels are already good enough...
     
  3. MADMAND

    MADMAND
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  4. yan

    yan
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    Thanks for that guys, that was helpful. I appreciate that most 32in or smaller LCDs have addressed most of the issues I outlined, however I want a big screen and the black levels are an issue for me. I have to say I am now disappointed with the black levels of my 503 (although when I purchased it they were considered to be good). I recently saw the the Panny TH42PA50e, I thought it was amazing in terms of colours, black levels and brightness.

    The other worry is repsonse times, I am an avid football fan and dont really want to see 2 balls flying around the screen or a ghost second ball.

    Also the viewing angle is an issue as my room is wider than it is long so there will be people sitting at an angle (naturally I will have the straight-on seat :D)

    I have just bought a few magazines to do some further reading, this is what "What Home Cinema" had to say:

    Plasma
    Plasma screens are generally larger than LCDs and offer superior contrast viewing angle, response time and colour saturation to LCD screen. However the downside is that plasmas tend to suffer from screenburn from onscreen logos.

    LCD TV
    One of the most immediate advantages of LCD over plasma is the slimmer and lighter chasis. LCD panels are also reputed to last as long as plasmas and dont suffer from screenburn. Pictures are brighter and use less power, although contrast levels are't quite as good as those found on plasma's.

    The way I see it is that the slimmer lighter chasis of the LCD is not an issue as I wont be carrying it on my back :D it will be on the wall or the cabinet so this is a non-issue for me. They both appear to last as long as each other, which is good, but the the plasma is superior in contrast levels, viewing angle, response time and colour saturation. I have had my plasma for 2 years now and there are no issues with screenburn, I think you need to be extremely lax with your plasma to suffer screenburn with the new models. Therefore it leaves the issue of brightness which the LCD is superior, the issue of electricity consumption is hardly going to bust my bank balance despite a differnce being obvious.

    Im sure people will dispute this but as long as they do it like for like then thats fine by me. What I dont want is to start comparing 32in LCDs with 42in and 50inch plasma. Please bear in mind I am refering to larger LCD panels as I think its pretty much accepted that the smaller LCDs have solved the issues outlined in my original posting.

    What Im trying to find out is which technology is best for my viewing habits as oppossed to which technology is better.

    Yan
     
  5. yan

    yan
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    Am I to assume no-one has an LCD above 32in or is it people are not willing to comment on the aspects of their 42in LCDs thast they are not happy with.
     
  6. Nick_UK

    Nick_UK
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    I have a 42" plasma in the lounge, and a 26" LCD in the dining room. I would say, without any doubt, that the plasma gives better pictures. On the LCD, colours change with the viewing angle. There is motion blur on the LCD. Most worryingly, I have two insects that have crawled in behind the screen and died, and now I have 4 "pseudo" dead pixels ! I will stick to plasma screens in the future.
     
  7. Jakus

    Jakus
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    Let's be perfectly honest, If You are comming from a top CRT which myself and a couple of Friends belive as a 32" being optimum for current TV and media, The only real downside is very Dark Films and Scenes Look Poor and if You up the brightness to regain detail it all goes Grey !
    I don't care what anyone says they are all the same (I have a £1200 21" LCD pc monitor it's the same also!)
    Back to size, as before if a 32" crt had nicely saturated images You need to be looking at around 26" LCD to look about the same with current definition TV above that it's all getting a bit diluted !

    My take on it is with my 37" LCD
    SD tv = Just about watchable
    DVD = some movies are really quite good
    HD = spectacular
    PC (dvi ) = fantastic perfect geometry and detail easily as good as a Monitor

    My advice Buy a Cheap but reasonable LCD so in a couple of Years You can upgrade when technology has advanced.. ;)
     

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