How Video Works - pág.49

These monitors are good for most general television production applications. They may be stand-alone single displays, or they may be multi-image processors that can display several small images on a single large monitor. This type of display is often seen in control rooms where many images must be viewable at the same time.

Finally, there are top quality monitors used for critical color judgments. These are often found in finishing editing suites and in color correction applications. Called "Grade 1" or "Reference" monitors, it is not uncommon to see these units costing thousands of dollars each. If you are making the final color judgments on high-end or broadcast productions, these are the units to seek.

Video Displays

The original method of displaying video was through the use of the cathode ray tube (CRT). This type of display is called direct view, with the receiver or monitor being rack-mounted or placed on a stand. The screen size ranges from a few inches up to a fifty-inch picture tube. CRT´s are no longer manufactured, replaced by several different flat screen technologies described below.

LCD

The LCD (liquid crystal display) uses a fluorescent backlight or, in newer versions, LEDs (light-emitting diodes) to send light through liquid crystal molecules. On the display screen there are red, green and blue pixels that are connected by an array of wires. By applying voltage to the pixels, backlight can either be allowed or prevented passage, thereby illuminating the screen. As most of the light generated by the backlights is blocked at any given time, these displays draw quite a bit of power. LCDs are not perfect in blocking all the light when they should be black, which makes getting truly deep black images a challenge.