Thread: LCD FAQs

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  1. #1
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    LCD FAQs

    LCD FAQs - Guides u will like to know!

    Type of different panels
    TN (Twisted Nematic) - 6+2 bit dithering panel 16.2mil
    Fastest respone for gaming
    Picture viewing normal
    DVD playback normal
    Limited viewing angle

    MVA/PVA (Multi-Domain/Patterned Vertical Alignment) - 8 bit panel 16.7mil
    Good respone
    Picture viewing good
    DVD playback good
    Good viewing angle

    IPS (In-Plane Switching) - 8 bit panel 16.7mil
    Intermediate respone
    Picture viewing good.
    DVD playback good
    Best viewing angle



    Desktop LCD "native resolution"
    You'll notice almost all 17" & 19" monitors have 5:4 aspect ratio, unlike 1600x1200 which is 4:3. Unlike CRTs, LCDs have square pixels so 1280x1024 are set somewhat of a funny resolution due to its 5:4 aspect. If you look at 21" LCD monitors you will notice that their aspect ratio is wider, since they use the standard 4:3 ratio.

    As you may know, all LCD monitors have a "native resolution", as they have a set number of pixels. You can't go higher, and going lower forces the monitor to stretch the image out amongst the pixels, which will obviously cost you some image quality. Now, if you're quite the gamer, then you'll know that a handful of old games use a resolution of 1280x960 as opposed to 1280x1024. Why? Good question. In fact, the question should be, "Why isn't 1280x960 the standard resolution?" It should be.

    If you go by the 4:3 ratio that almost every other resolution follows (like 640x480, 800x600, 1024x768, etc.), 1280x960 should be the standard, not 1280x1024. Well, regardless of who's to blame for this odd conflict, it ends up robbing LCD owners of happiness in the end which means you have to make a sacrifice when using such LCDs: either accept 'non-round circles', bar/window screens or operate the LCD at a non-native resolution.

    Aspect Ratio
    {4:3} 10" 640x480 - VGA
    {4:3} 12" 800x600 - SVGA
    {4:3} 15" 1024x768 - XGA [PS=0.297]

    {4:3} 17" 1152x864 - Not used in LCD!
    {5:4} 17" 1280x1024 - SXGA [PS=0.264]

    {4:3} 19" 1280x960 - Not used in LCD!
    {5:4} 19" 1280x1024 - SXGA [PS=0.294]

    {4:3} 20" 1400x1050 - SXGA+ Used mainly in notebook 15" LCD!
    {4:3} 21" 1600x1200 - UXGA [PS=0.270] The display really feels like a wide screen!



    LCD Refresh rate
    LCD digital wave make it sharp texture, but some like CRT sine wave which make a smooth texture, DVI make text looked nicer, with less smearing & waving and looked better than CRT color in term of sharpness especially helpful for 19" & above. But sometime really depend on a good DVI graphics card & DVI-D shielded cable.

    8-bit DVI LCD - 1280x1024 color improvement over VGA approx 30% (6-bit approx 10%)
    8-bit DVI LCD - 1600x1200 color improvement over VGA approx 60%

    LCD & CRT Refresh rate
    Ms - Hertz are inversely proportional
    25 - 40
    20 - 50
    18 - 56
    16 - 62.5
    12 - 83.3
    8 - 125
    4 - 250

    LCD technology latest now had 2ms (gray-to-gray)
    CRT technology already had approx 0.1ms (gray-to-gray) to 0.5ms in relative response.
    Technically a 16ms LCD would be enough, & virtually no ghosting for human eye at 60Hz.

    Pixel refresh rate for LCD are measured when image needs updating only when changes. No matter how fast your LCD, there still some minor choppiness/artifact during gaming FPS due to current limitations of LCD at maximum 75Hz.
    LCD @ 60Hz with V-Sync ON: noticeable choppiness, but with consistent image & less artifacts
    LCD @ 60Hz with V-Sync OFF: smooth & fluid motion, but minor inconsistent image & noticeable artifacts (tearing)

    If you are looking for a frame rate advantage in your 3D game or video benchmark, and not overly concerned about image quality, try disabling the VSYNC or 'wait for vertical synchronization' setting in your direct3D and OPENGL settings. The VSYNC setting basically forces the video card to conform to the screen refresh rate of the monitor, meaning that the card will not send new display data to the monitor until the previous data has been fully displayed.

    This has the effect of capping the maximum frames per second displayed at the refresh rate of the monitor. Newer video cards especially may well be able to render considerably more frames per second than this, and disabling VSYNC will allow them to. The penalty for this varies. In some games, image quality loss will be imperceptible. Try disabling VSYNC and observing the results, especially if you are trying to boost benchmark scores.

    To disable VSYNC on ATI cards: From advanced display settings, go to the '3D' tab and check the 'use custom settings' box for both direct3D and OpenGL. Press the 'custom...' button to access the controls for both modes. Turn the 'wait for vertical sync' slider all the way to the left.

    To disable VSYNC on Nvidia cards: From advanced display settings, go to the tab that identifies your video card model. The VSYNC settings are located in 'more direct3D settings' and 'OpenGL settings.'

    Of course setting higher refresh rate are better for LCD gaming or video, but is also depend on your graphics card quality & LCD panel which commonly are optimized for 60Hz which are more suitable for text and image viewing. As it is expensive to increase higher hertz due to cost & standard and single frequency transmission are more than enough for normal LCD users. Furthermore CRT are still the best for DVD/Video viewing & 3D gaming.



    LCD color setting
    Try to manual set colors to 40-50%
    Set brightness to 0 & contrast around 20-40% to suit your taste.

    Flourscent lights are constant pulsing rate, when LCD contrast are set to low setting, flickering may occur due to insufficient light source passing through the pixels. This are more obvious for green (eye-sensitive) color grid pattern.


    Graphics card for LCD
    There are minor difference in ATI & Nvidia - 2D color image & text viewing, ATI graphics card tend to produce sharper image/text whereas Nvidia tend to produce more accurate image color at the expense of sharper image/text & vice versa, hence this are a trade-off between this two graphics card makers.

    But many people switch from Nvidia to ATI will find sharper image, hence overall quality increase, but for photography image, some budget people may switch to Nvidia less matrox card for more color accuracy over ATI. But modern Graphics cards will not have much difference now.

    For 3D gaming, most people will prefer higher fps than image quality, either one are fine.



    DVI cable
    For those who have problem with DVI-D to DVI-D, no signal during bios or desktop, do contact your display device manufacturer and obtain an updated firmware that addresses the EDID problems. Those using DVI-I/Convertor to VGA cable would not be affected due to data being transmitted by the 4 extra VGA pins.

    What is DVI? - A Guide to the Digital World
    How to Choose the Digital Video Interface / DVI - Digital Video Interface-Best Computer Online Store Houston Buy Discount Prices Texas-Directron.com

    Digital Visual Interface - Wikipedia, the free encyclopedia
    All About DVI

    DVI-D Single - SGD$20/25 (1.8/3.0)m


    DVI-D Dual - SGD$30/35 (1.8/3.0)m





    Backlight Issue
    When buying LCD, beside checking pixel problems, must check for blacklight bleeding at max setting with black color; tone down contrast to 40% check brightness uniform & viewing angle whether u like it or not...

    One example of backlight bleeding, it usually occur around the screen edge when in black color background. Minor bleeding & screen uniformity are usually not covered under warranty.



    Panel Grading
    LCD panels are very complex things, and some will have defects such as dead pixels, which occur when a transistor fails. The LCD panel manufacturers test the panels, grade them accordingly, and then sell them on to monitor manufacturers.

    Many manufacturers use a third party firm to provide the panels. Panels are rated as A, B or C grades. Less grade mean higher chance of pixel problem during the warranty period.

    Grading dp/bp/(sum of dp+bp)
    Grade A : 0/0/1 (100% without dead pixel problem, at the max 1 semi/bright pixel problem)
    Grade B : 3/3/5
    Grade C : 5/5/8

    TN panel production are quite stable (Higher yield) for now.
    Those having laptop & zero pixel warranty should be Grade A panel.
    The rest TN panel should be either Grade A or B panel depend on different LCD models & batches.

    MVA, PVA, IPS panel are more expensive as yield are lower.
    In future those having MVA, PVA & IPS panel should insisted on testing on spot before paying.



    LCD Lifespan
    The lifespan of an LCD is typically 50,000hrs, Lamp life 30,000hrs, based on 24x7, LCD panel is about 5.7yr & Lamp life is about 3.4yr. But more concern would be the LCD powerful always-on backlight lamps which will show some "wear" like any lighting appliance, to be dimed over time usage. The first to fail will always be the lamp light except for pixel related problem.

    As LCD consist of an array of millions of transistors in a grid pattern, knocking or pressing too hard can likely to destroy a patch of transistors or entire display. But if allow 1 to 1 exchange, they can also give u a reconditioned or 3rd graded LCD meaning 1 to 2 pixel problems within warranty specification/period.



    LCD syndrome
    All LCDs had anti-glare/scratch coating, a screen filter are usually not needed as heat disspate may affect your pixels performance. 1st timer user may take sometime to get used to the lamp light. I rather u take more extra care on your anti-glare glasses from scratches.

    Some users have negative effect on flourscent light from LCDs, some are due non-native resolution setting, other are having room lighting having incorrect position, or can't get used to sharp text/image from LCD but windows users may download customized smooth font-type.



    More informations here
    X-bit’s Guide: LCD Monitor
    X-bit’s Guide: Contemporary LCD Monitor Parameters and Characteristics - X-bit labs

    What is TFT LCD
    http://www.netbored.com/classroom/what_is_tft_lcd.htm

    TFT / LCD FAQ
    http://www.zone365.com/content/tft-lcd-faq/1

    CIFI.COM - LCD Buying Guide Part 1
    CIFI.COM - LCD Buying Guide Part 1

    LCD: everything, you’d like to know...
    [url=http://www.nvworld.ru/docs/lcd_e.html]
    Last edited by elladan; Apr 25th, 09 at 02:32 AM.

  2. #2
    Master of past & present Shamino's Avatar
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    Powerful info there!!
    thx for spendin the time to typ ethis!
    possible to include examples of each panel?

  3. #3
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    WOW NICE ! i vote for STICKY !!!!!
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  4. #4
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    This is a darn good read!!!!
    "Now, now, my good man, this is no time for making enemies." -- Voltaire His last words on his death bed when asked by a priest to renounce Satan.

  5. #5
    Wouldnt it be nice.... feitz's Avatar
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    very very useful!!... now i know how to explain why the black on my 710N doesnt look good. good some bleeding problem though i dont really mind it that much.

  6. #6
    good one, thanks~!
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  7. #7
    Best In All The Forums I Read...

  8. #8
    evolutionX
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    that's really a good one!!!will spend my time reading that when free...

    thanks!!!


  9. #9
    nice very nice so any recommendations for good 19" this coming PC show? planning to get one but not sure which one... Samsung 930BF 4ms gd or not? $499 now at SLS for 4ms, looks good and cheap to me

  10. #10
    Just some comments and corrections.

    Quote Originally Posted by Spirax
    TN (Twisted Nematic) - 6+2 bit dithering panel 16.2mil
    There are 8 bit TN panels. The Benq widescreen is one example.

    On response times, the published ms ratings make no sense, because you must view the response times against different states of switching. You'll find that many of the "4ms" numbers are taken at the most optimum settings, and that they can stretch to as high as 24ms in other states of switching!

    Also not mentioned is how the transition looks. IPS traditionally looks smoother, so at 16ms it's less objectionable than a VA at 16ms.

    Well, regardless of who's to blame for this odd conflict, it ends up robbing LCD owners of happiness in the end which means you have to make a sacrifice when using such LCDs: either accept 'non-round circles', bar/window screens or operate the LCD at a non-native resolution.
    It will be a perfect circle as long as the OS is sending a native 1280x1024 signal. In fact it's when you force the LCD into a non-native resolution that's when trouble starts, though modern nVidia and ATi drivers can compensate for that nowadays.

    LCD color setting
    Try to manual set colors to 40-50%
    Not advisable unless you have a hardware calibrator on hand.

    Flourscent lights are constant pulsing rate, when LCD contrast are set to low setting, flickering may occur due to insufficient light source passing through the pixels. This are more obvious for green (eye-sensitive) color grid pattern.
    Last I checked the CCFL tubes in LCDs are not meant to flicker. If they flicker the panel is not manufactured properly!

    [quote]There are minor difference in ATI & Nvidia - 2D color image & text viewing, ATI graphics card tend to produce sharper image/text whereas Nvidia tend to produce more accurate image color at the expense of sharper image/text & vice versa, hence this are a trade-off between this two graphics card makers.
    [quote]

    That shouldn't be the case now with DVI connections.

    6-bit LCD may want to use ATI for sharper image/text.
    8-bit LCD may want to use Nvidia card for more color accuracy.
    Not quite getting your rationale here.

    can't get used to sharp text/image from LCD but windows users may download customized smooth font-type.
    If you're using XP just enable Cleartype and download the Cleartype Tuner Powertoy.

    Mandatory reading.

    The best place to get information on LCD monitors is http://www.prad.de/en (helps if you know German so you can ask questions in the more active German forums).

  11. #11
    woot elu's Avatar
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    I'll want to add http://www.tftcentral.co.uk/articles.htm too. Times have changed much since the threadstarter posted his guide.

  12. #12
    so does it mean that normal usage of 5 hours daily, my LCD monitor can easily last for 5 years?

  13. #13
    hahaah where u get all these info one??

    ur info is correct though not complete, there is far more defects in LCD than wat u mention.

    I noe becos i work in a LCD making com

  14. #14
    pilot wannabe who cant be TheHypez's Avatar
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    hmm the lower the ms or the higher the ms is better? keep getting confuse or forget after a short while after asking people

  15. #15
    nice...

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