TFT, LCD which one

Discussion in 'other software & services' started by dober, Oct 21, 2004.

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  1. dober

    dober Guest

    Planning to buy one of these flat monitors (not flat CRT) they look nice BUT
    I wonder between the terms TFT and LCD are they different, if so, which one. Thanks
  2. nadirah

    nadirah Registered Member

    Oct 14, 2003
    You could try a 17-inch LCD monitor.
  3. Sweetie(*)(*)

    Sweetie(*)(*) Registered Member

    Aug 10, 2004
    Try and get 1 with a good warranty, sometimes you get problems with dead pixels.
  4. dober

    dober Guest

    Thank you both
    BUT my question:
    is there a difference between a TFT minitor and an LCD one
  5. ronjor

    ronjor Global Moderator

    Jul 21, 2003

    As far as I know, LCD monitors are allowed a cetain number of "dead pixels".
    It can be annoying if you use your computer a lot. At least, it was for me.

    I find the old crt still renders faster than lcd. The downside of a crt is heat and energy usage.

    What are LCD monitors?

    LCD stands for "Liquid Crystal Display". The basic components of LCD monitors are two sheets of specially treated glass with a liquid crystal solution sandwiched between them. The monitor works by sending electricity through the glass to change the color of the liquid crystal. The design attributes of LCD monitors enable them to be extremely thin (nearly flat), which means they take up much less desktop room than conventional (CRT) monitors. This space-saving feature is one of the biggest reasons for the growing popularity of LCD monitors.

    Is it true that LCD monitors are easier on your eyes?

    Yes. Unlike CRT monitors, the images on LCD monitors refresh a pixel, rather than an entire line, at a time. The images on CRT monitors (as well as televisions) are redrawn at a rapid rate not usually discernable to the eye. This is why photographs of television and CRT screens don't turn out (and why when you look into a dark room brightened only by a television there seems to be mild strobe effect on the walls of the room). This refreshing of CRT screens (measured as frequency) can cause eyestrain for some people. LCDs do not flicker and often cause less eyestrain.

    TFT standard LCDs (TFT stands for "Thin Film Transistor") are also easier on your eyes because they do not emit low levels of electromagnetic radiation, a field released in very small amounts by CRT screens and non-TFT LCDs. The long-term effects of exposure to electromagnetic radiation is unknown and still being studied, though one expert has advised that sitting more than 28 inches away from the monitor will greatly reduce your exposure.

    Do LCD monitors consume less energy than conventional monitors?

    Yes. In fact, they typically consume 70% less energy than a CRT. The amount of electricity required to animate the liquid crystal in LCDs is simply less than the amount needed to power a CRT.

    Is LCD resolution inferior to the standard (CRT) style of monitor?

    No, not necessarily. The resolution of LCD monitors has greatly improved in the past year, and now the image quality on LCDs can be just as clear and clean as a conventional CRT. It's true that older LCDs don't match CRT monitors in resolution, but new LCDs are top-notch. LCD monitors, in fact, can have a brightness rating (of 300 nits or more) that can make LCDs easier to view in direct or indirect sunlight than CRTs.

    If, however, you want to play action games and high-end gaming software on your computer, you may want to opt for a CRT. The depiction of fast-moving graphics on CRTs is still slightly better.

    CRTs will often offer better resolution if you're looking to distinguish subtle shades between similar colors. These differences are more noticeable on CRT monitors because CRTs still typically have a larger contrast ratio than LCDs. Contrast ratio describes the ratio between black and white on the screen — and the larger the contrast ratio, the better subtle color differences will be displayed on the screen.

    How is LCD resolution measured?

    There are four important determinants in LCD resolution:

    · Number of pixels, or dots of color. A monitor with a resolution of 1024 x 768 pixels, for instance, displays a total of 786,432 pixels on the screen. The more pixels, the sharper the screen images. (1024x768 is a solid resolution for LCDs.)

    · Contrast ratio describes the ratio between black and white on the screen. The larger the contrast ratio, the better subtle color differences will be displayed on the screen. Contrast ratios start at 200:1 and 250:1, while the best models are as high as 400:1 or 500:1.

    · The video graphics card on your computer has a lot to do with how well colors will be displayed on your LCD screen. If you're using a computer that's over two years old, there's a good chance that the video graphics card is not large enough. You should have at least a 32MB, and preferably a 64MB, video graphics card to go with your LCD monitor.

    · The brightness of the display is measured in nits, which describes the intensity, or luminescence, of visible light. The more nits, the brighter the display. LCDs commonly range between 75 and 300 nits.

    How can I optimize the resolution on my LCD?

    Your LCD will operate at an ideal resolution (setting the resolution too high or too low for your monitor will yield an imperfect image). If your resolution setting gets thrown off for some reason (such as being manually adjusted by another user), you can re-set the resolution by using the diskette that comes with your LCD monitor. Start by inserting the diskette and choosing the "auto.exe" program. Next, press the i-key on your keyboard to enact an automatic adjustment.2 An important tip to remember: don't clean the display screen of your LCD monitor with glass cleaner. Screen covers on LCDs are made of plastic, which is degraded by glass cleaner. Instead, use a clean cloth barely dampened with a mixture of vinegar and water, or with a mixture of water and tiny amount of soap.

    How should I position my LCD monitor to avoid or reduce eye and neck strain?

    Place the monitor 18 to 30 inches away from the front edge of your desk. Make sure you're not craning your neck up or down to view the monitor. If you are, adjust either the monitor's tilt or the height of your chair. (To adjust the height of the montior, use either a monitor riser or a swivel arm. Click to see monitor risers. Click to see monitor swivel arms.) If after adjusting your chair your feet no longer touch flat to the floor, consider using a foot rest. (Click to see foot rests.)

    When should I choose a traditional CRT monitor instead of an LCD?

    This question refers back to the previous one about the image-quality of LCDs. If you want to play action games and high-end gaming software on your computer, you may want to opt for a CRT instead. The depiction of fast-moving graphics on CRTs is slightly better. Also, the contrast ratio on CRTs is usually better, so subtle shades of gray and of color in the graphics or text will be displayed "more true" on CRTs. If you're concerned about image-distortion on a CRT (caused by the curvature of the monitor glass), you can opt for a flat screen CRT.
  6. dober

    dober Guest

    much appreciated
  7. Devinco

    Devinco Registered Member

    Jul 2, 2004
    Excellent post Ronjor!

    I recently bought one and would like to share the info I learned in the process.
    Anyone considering a new monitor for their main computing screen should really get an LCD. It will save your eyes! A 17" LCD is about equivalent actual viewable screen size to a 19" CRT. The screen is truly flat with no glare.
    Most of the Consumer models will be TFT. The older DSTN was used mostly in lower end laptops had lower contrast and limited viewing angles. Plasma displays are mostly in the larger flat panel TVs. Organic LCD have better color but they are having production issues. If you can hold off buying till next year, current over production surpluses will drive down the average cost about $100 in 2005.

    Current LCDs have gotten much better with the dead pixel/stuck on sub-pixel.
    It is still annoying to spend a decent chunk of change on a monitor and find out it is defective (stuck on red sub-pixel). It is even worse when the manufacturer says it is not defective enough to replace it!! :rolleyes:
    A dead pixel is when all three sub-pixels (red, green, blue) won't turn on.
    A stuck on sub-pixel is when one of the three colors is continuously lit.
    A stuck on red sub-pixel will show up as a tiny red dot. It will be most visible on black or dark blue backgrounds but practically invisible on white or lighter backgrounds. It is also harder to see on heavily textured background. Different manufacturers have different allowable dead pixel/stuck on sub-pixel policies. Some even say the defective sub-pixels have to be clustered a certain distance from each other before they call the monitor defective.

    When I bought one from a major retailer, I thought I was being smart. I paid for it then hooked it up right there in the store to check it out. Unfortunately, I did not attach the stand, so I had to balance it and did not give it as thorough a test as I should have. It looked good on the cursory inspection, but once I took it home, it had a stuck on red pixel. Here is what I will do next time.

    Attach the stand (bring a small stubby screw driver just in case) and hook it up to a computer right there in the store. Spend some quality time with it and let the monitor warm up. Next time I will make sure I spend about 30 minutes to make sure it has reached its normal operating temperature. Ask the clerk how to exit the store/demo/screensaver to get to the desktop. Send the clerk away so you don't feel pressured to hurry up. Change the resolution to the LCDs "native" resolution. On a 17" LCD, this should be 1280x1024 (remember the original res so you can switch it back). Change the desktop background from the shaded/textured to a solid black color (remember what desktop background they used so you can switch it back). Now look at every square inch of it very carefully. If you see a tiny red dot, that is a stuck on red sub-pixel. You can also change the desktop to white, red, blue, and green, but black will show you the most annoying defect, the stuck on red pixels. If it is very near the edge, then I would let it go, but if it was in normal working view, I would box it up and try another. Just say you don't like this one and want a different one. You don't have to say why, it just doesn't look right. If they give you trouble then get a refund and walk away.

    These are just my opinions, but I don't think they should allow these defective pixels/sub-pixels in a display. Sure it is difficult to make the displays perfect, but then they should sell them accordingly: Grade A, B, C and price them accordingly. Instead they try to hide the defects from consumers and have ridiculous warranty policies. I know some people won't notice the defects and some won't care, but I do. This is the biggest problem with LCDs and even with it, they are still much better than a CRT when you take it all into account.
  8. Pilli

    Pilli Registered Member

    Feb 13, 2002
    Hampshire UK
    Hi Dobar, IIyama is the one recommended in the PC Pro magazine in particular this one Same model number everywhere I believe.
    It has a fast response time and is very bright with good colour depth and is reasonably priced.

    Now would appear to be a good time to buy if you live in Europe as the EEC taxmen have deemed TFT monitors subject to import tax as they are now classed the same as TV's - This tax is 15% which willbe passed on to users. There is still a very slight chance that this may only effect 19" monitors due to pressure from the producers.

    Many of the larger manufacturers are rushing to set up production the the old Eastern European countries to get over this Tax hurdle.

    Cheers. Pilli
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