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Some information you need to understand about LCD and TFT monitors
Introduction
Often, during the course of our IT support work we find users with incorrectly set-up TFT or LCD monitors, resulting in a very poor, blurred or fuzzy display.
The users are often unaware that the poor display is something easily resolved, let alone know where to start - so, here's our quick guide to what you should know about LCD or TFT screen - but were never told!
Background - the CRT Monitor
Before LCD screens were common, we were all used to CRT (Cathode Ray Tube) based monitors. These were generally large, heavy items and had gradually gone from 14", 15" to 17" display sizes and above, typically for specialist CAD users.
Users were generally familiar with the ability to change the Screen Resolution/ to suit their needs, regarding the size of displayed text - or preferences, depending on the screen size.
It should be noted that the Screen Size for a CRT monitor is the actual size of the display tube, measured diagonally - NOT the display size. This is why a 17" CRT monitor typically has a Display size of around 15.5"
Also, it should be remembered that a CRT monitor Projects the picture from the back of the tube, onto the inside of the screen, where three different types of Phosphor glow to produce Red, Green and Blue light, to make up the image.
It is this method of projecting the image that results in a picture that can Never be perfectly sharp on a CRT monitor - and this is why some users are willing to accept a fuzzy or blurred picture on a LCD or TFT monitor - when it should be perfectly sharp.
The Difference with LCD and TFT Technology
With an LCD or TFT screen, there is NO projected image. Instead, the screen is made up of many sets of three tiny light sources, Red Green and Blue, one for each and every Pixel on the screen. A 15" screen would normally have a resolution of 1024 pixels horizontally by 768 pixels vertically, giving 786,432 pixels with three light sources each, making 2,359,296 tiny light sources in all.
This resolution, i.e. 1024 x 768 pixels is called the Native Resolution of the display.
Important fact No. 1 - The Importance of Native Resolution:
This native resolution IS THE ONLY correct resolution for the display to work as designed. If a lower resolution is configured on the PC, for example 800 x 600 pixels, and this fills the whole screen, then 800 dots are displayed stretched across 1024 actual pixels horizontally and 600 dots across 768 vertically which cannot fit without each dot overlapping two actual pixels, which results on a very blurred display.
It is for this reason that screens MUST be configured in their Native Resolution. Even though this results in a smaller text size, the text is (or should be) very clearly displayed. This results in much reduced eye-strain compared to the larger, but blurred image obtained by using the wrong screen resolution.
Important fact No. 2 - Bigger screen DOESN'T mean Bigger Text - but it CAN mean SMALLER!
So, from the above you can see that it is no longer possible to simply adjust the display resolution to effect a simple change to the size of the text on-screen. This causes a second 'Nobody told me' issue as users are frequently sold a 17" LCD/TFT screen as an upgrade from a 15" screen.
Bear in mind that a 15" TFT / LCD Screen has a display size almost the same as a 17" CRT monitor - but a perfectly sharp picture when correctly configured, so a 15" TFT/LCD monitor is the correct replacement for a 17" CRT monitor.