Purchasing an HDTV When LCDs Give Me Headaches

Discussion in 'Science and Technology' started by Spot's Meow, Nov 13, 2011.

  1. Ar-Pharazon

    Ar-Pharazon Admiral Premium Member

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    Is that Organic LED?
     
  2. Psion

    Psion Rear Admiral Rear Admiral

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    Aside from the use of organic compounds for luminescence, I'm not sure why. Certainly they're a closer match than LCDs which are an entirely different technology.

    Now if you really want amazing colors, wait for QLEDs. Better colors than OLED, but just as thin and much brighter for the same power use.
     
  3. sojourner

    sojourner Admiral In Memoriam

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    Not true when talking about display technology.

    There is OLED, LCD, and LCD using LED backlights which have been short named as LED.
     
  4. belikej

    belikej Cadet Newbie

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    Its very annoying that just because people don't have an answer for you they decide it must be psycological :rolleyes:

    I have the same problem myself and the cause of LCD induced eye strain actually has been identified. It is because the the light coming out of the screen is polarized. Polarization of the light is required to get it concentrated enough to pass through the crystal display.

    For any who don't know, polarization is when all of the light rays become aligned so that they are all in synch and going in the same direction at the same time, which is an abnormal condition for light, and only occurs in nature when light gets reflected off a surface like mirror and causes that bright, painful sheen.

    It is the very same principal used to create lasers, only the light in your television is not quite as potent. LCD eye strain is not uncommon but unfortunately, isn't common enough to slow the tidal wave of lcd's flooding the market and washing away CRT's.

    I do not know if plasma screens cause the same issue, and was searching for the answer to that question myself when I came across this post. If I could I would just buy another CRT but they haven't been sold in stores anywhere near me for several years now.
     
  5. RobertVA

    RobertVA Fleet Captain Fleet Captain

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    The very principle LCDs use to turn pixels on and off depends on polarized light. Imagine someone throwing Frisbies (TM) at an old fashion iron bar fence. A flat Frisbe stops when it hits the bars. A Frisbe on edge goes through. Depending upon their being electrically activated or not, the liquid crystals rotate the polarized light so that it can go through a second filter. The displays on most wristwatches and battery powered calculators use the same phenomina.

    I'm still thinking flicker or the color spectrum of the back light is a more probable cause of any headache problems some people have. A lot of people prefer to watch TV in a dimly lit room, but the low light levels might make their pupils dilate, which might expose the retina to stronger light levels from the display. With some people there might even be an element of eye fatigue after a day at school or work using computer terminals.
     
  6. belikej

    belikej Cadet Newbie

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    I've read a number of theories online including flicker from the florescent back light to a post saying faster refresh rates on a LCD would be beneficial because....well it would be easier to quote it than explain, and I'm not sure how to evaluate it for merit so here it is:

    /quote
    "LCD's shutter horribly when scrolling text, or in video games, or watching movies because of the draw-and-hold technology they implement. Without hashing through the gory details, your brain gets a little messed up interpreting the motion of an image that is produced through this method. Basically your eye sees an infinite number of 'fps' but you are looking at 60 still images a second held for 16 ms each. This is opposed to say 60 'instantaneous' flashes that a CRT might generate, which mimics how our eyes actually look around and how our brains perceive motion.

    Originally LCD's were crap because of ghosting, which was a refresh rate thing. Now we are down to the several ms grey-to-grey flip rate for pixels on your screen, so this is not a problem anymore. A 5 ms event will happen 200 times a second, or 200Hz, if you will. What this does allow us to do is allow us to effectively increase the refresh rate of the draw-hold technology we are dealing with until a point where it no longer appears to be draw-hold to our brains and things can operate smoothly.

    This is why we need refresh rates that don't suck! There is lots written about this... feel free to look it up.

    If you don't believe me just grab your scroll bar and start scrolling while trying to read this. It shutters to the point you can't read it comfortably. Also, the wheel mouse/down arrow keys don't count cause they aren't continuously scrolling. "

    /endquote

    There is an article out there where a guy replaced the back light to his LCD with incandescent lighting and claims all his problems went away. Obviously he believes the problem is florescent flicker.

    All I do know for sure is that I can stare at a CRT for 12 hours continuously, even during lunch, 5 days a week, and walk away with no eye strain, but I cannot even look at an LCD for 10 minutes without feeling a distinct pain in my eyes that is accompanied by a headache and nausea if I persist any longer than 10 minutes. I've tried all the little tricks from sitting farther away, adjusting brightness and contrast, different sizes and resolutions, etc.

    I've decided to buy a plasma tomorrow and see if it helps.
     
  7. John O.

    John O. Rear Admiral Rear Admiral

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    I would imagine that a 240 hz LCD would resolve your eye issues.
     
  8. YellowSubmarine

    YellowSubmarine Vice Admiral Admiral

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    That's a seriously confused statement, and I'm not sure how should I interpret it, but the way CRTs generate images has nothing to do with the way the brain perceives motion, and watching a 60 Hz CRT is anything but pleasant and tolerable. I didn't go on reading the explanation, fearing that I might get the same anxiety and headaches...
     
  9. Haggis and tatties

    Haggis and tatties Vice Admiral Admiral

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    It's possible that the smaller yet more detailed area if a LCD and a high resolution are straining your eyes.....next time you use the monitor make the resolution lower, say 1024(assuming its not already), also make the font's bigger......see if that stop's the headaches.
     
  10. MacLeod

    MacLeod Admiral Admiral

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    Aren't LED backlight considered to be the best. Higher contrast ratos etc...
     
  11. Sean Aaron

    Sean Aaron Rear Admiral Rear Admiral

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    For this reason I was going to suggest glasses, even if only reading ones for extended screen time. In my job I need to use them all the time. Now that I'm officially in my forties I have noticed a slight inability to focus on distant objects, but I find this exacerbated by extended screen use as my eyes get overused to looking at something close-up and make it difficult to refocus on far away things when I leave the office.

    I have 20/40 vision so normally I don't use glasses, but I always use them for driving and looking at flat panels like my office displays and my plasma screen at home.

    I went for plasma mainly because I didn't want to put a lot of research into which LCD TVs have better image processors, etc. to compensate for the inherently inferior method of producing blacks: i.e. screening out part of the illuminated screen rather than lighting individual pixels. I suppose that might also be of benefit for anyone affected by the backlighting, but I won't claim any special knowledge in that area.

    I will say generally that researching the headaches I was experiencing every few years and identifying them as cluster migraine was a great help. Oliver Sacks' book "Migraine" was an interesting (if clinical) read and a great resource in this regard.
     
  12. Saturn0660

    Saturn0660 Rear Admiral Rear Admiral

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    LED's are getting close. But they still don't have the black levels of Plasma's nor the smoothness.
    Plus like has been said.. LED's are still LCD tv's. Just the light source is LED. In most cases it's not back lit it's edge lit.

    As far as Full LED tv i'd like to see a link as i'm not aware of any sold in the US.. I don't count the shitty sony x-1 11" job. That thing wasn't even HD.

    Last Note. Don't worry about contrast ratios. Dynamic ratio doesn't mean anything as there is no standard.
     
  13. Saturn0660

    Saturn0660 Rear Admiral Rear Admiral

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    Not really.. Most HDTV just stick black frames in there to give you the 240Hz. Plus as always, the channel is still in 60Hz.
     
  14. backstept

    backstept Rear Admiral Rear Admiral

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    it might also be a color temperature issue . . . if the screen displays 'white' and you hold up a white piece of paper next to it and either paper or screen appears slightly more blue or red than the other, then you should adjust the color temperature to match the light in the room
    for instance, incandescent lighting is quite warm (red), while fluorescent light is quite cool (blue), and sunlight is in between
    basically, you want to white-balance the display :D
     
  15. Saturn0660

    Saturn0660 Rear Admiral Rear Admiral

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    True dat. Get your set ISF calibrated. See HD as it was meant to be.
     
  16. belikej

    belikej Cadet Newbie

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    backstept thats an interesting idea.

    Anyway I ended up calling a tv repair tech to fix my old CRT Television and when he told me it wasn't worth the money to repair, I explained the problem. To my great surprise, and without skipping a beat, he told me I wouldn't have that problem if I buy a plasma. I did, and he was right! No more eye and head pain!

    I did ask him if he knew what the deal was, and he said that he has gotten numerous complaints about headaches with the LCD televisions, he said it had to do with the backlight as well as "other technical factors come into play" but did not elaborate. I didnt push him for more because I couldn't be sure he actually knew the cause or if he was repeating the same stuff I've read online.

    What I do know is that I tested my new plasma with a star wars marathon, all 6 movies back to back and no problems.

    Today my girlfriend had trouble with her laptop and I went to help her out with it......5 minutes later I've got pain in both eyes and head.
     
  17. EricF

    EricF  ̄ ̄ ̄ Chief Engineer

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    You'll find a plasma a much closer experience to a conventional CRT. In both cases you've got an electrical charge exciting a phosphor layer that produces the light through a shadowmask. The CRT uses electron guns to scan across a screen of phosphors, the plasma uses what essentially amount to lots os small pixel like cells with a phosphor coatings, the gas in those cells is excited by a small electrical charge causing them to glow (like neon lights).

    I wonder if it's the better contrast ratio that you get with both CRTs and Plasmas that helps avoid the headaches, whilst LCD based TVs and screens are getting better (LED driven ones are a good example) they still lag behind, you end up with much blacker blacks on a plasma because black is actually an absence of light as opposed to an LCD where it's the liquid crystal blocking the backlight (which gives you a dull grey rather than black). You may also find that plasmas and CRTs are a bit softer, since often the resolutions are much closer to broadcast resolutions (assuming we're in the land of standard definition signals since we're talking CRTs (you do of course get HD CRTs)) and avoid the upscaling in inherent with most LCDs along with a bit of bleed on the shadowmask, which I personally find nicer for SD pictures. Otherwise it will no doubt be down to refresh rates and the motion blur produced, but modern LCDs super-sample the signal up to 100Hz (120Hz in US) and employ some other trickery which improves things somewhat, but still even the best LCD crystals take about 2 milli seconds to switch states, which compares to plasma cell switching of 1 micro second. So it's hard to beat the switching capacity in a plasma.

    Out of curiosity I wonder if a proper OLED screen where each pixel is an OLED array would avoid the headaches, since again you've got a strong contrast ratio, who knows, it's not like they are massively common.

    Anyhow glad you've found a solution that works.