CRT screens are fast moving towards obsolescence and are now almost the preserve of Graphic designers, gamers and photographic professionals. In effect their large, bulky size has resulted in them being consigned forever to the recycling bin. Even so, their abilities far outstrip even the most modestly priced LCD or flat panel display. Why? Well, the refresh rate, color saturation, even-ness of brightness and ability to multi-sync (have more than one native resolution) means that they can still meet the requirements of high end digital users. Only a LCD displays offer true multisync and these are significantly more expensive than any CRT screen, either new or refurbished. So where do LCD displays beat the traditional CRT? I've already noted than they take up less desk space, but they don't flicker either and the glare is much less. As a result of this, eye strain is reduced significantly.

Liquid crystals were discovered in 1971 and comprise a liquid chemical compound that can be aligned precisely when subjected to an electric field. By placing rows of liquid crystals in between 2 polarizing filters (the same filters used in sun glasses) no light can pass through. Upon applying a charge to the liquid crystals, they are excited which causes them to align with the polarizing filter. If a light is shone through the layers, only those crystals that have been excited will allow the photons to pass through and align then up with the second filter. This is in effect how a monochrome screen was produced (basically black and white or on and off). Backlights, that produce the light source are cold sodium cathode tubes similar to ceiling strip lights.

In a color LCD screen, three liquid crystal cells make up each pixel. Each of those three cells has in front of it either a red, green, or blue filter. Light passing through the filtered cells creates the colors you see on the LCD. Nearly all modern color LCDs use a thin-film transistor (TFT), also known as an active matrix, to activate each cell. The process of manufacturing a TFT is similar to the process used to manufacture a silicon integrated circuit or silicon chip. Extremely thin insulators, conductors and transistors must be laid into a glass substrate, which becomes the lower glass of the LCD. TFT LCDs create sharp, bright images. Previous LCD technologies were slower, less efficient, and provided lower contrast. The oldest of the matrix technologies, passive-matrix, offers sharp text but leaves ghost images on the screen. This is because the electric field was not delivered directly to the liquid crystal because the TFT layer was not present.

Because LCDs address each pixel individually, they can create sharper text than CRTs, which, when badly focused, blur the distinct pixels that make up the screen image. But the high contrast of LCDs can cause problems when you want to display graphics. CRTs soften the edges of graphics as well as text, and while this can make it hard to read text at very small resolutions, it also means CRTs can blend and convey subtleties in photographs better than LCDs. Also, LCDs have only one "native" resolution, limited by the number of pixels physically built into the display. If you buy a modern 15 inch TFT, it's native resolution will be 1024x768. Emulating 800 x 600 on this screen will cause it to produce a picture where everything displayed looks to have fuzzy edges. A further note is that Many people claim that TFTs are crisper, but at close working distances the pixel structure is visible on a TFT. This is not the case on modern CRT screens, where the dot pitch is at or below 0.25mm.