The image you see on a monitor is made up of tiny dots of light called "pixels," short for "picture elements." The distance between these pixels is called the dot pitch. The closer together the pixels are, the clearer the picture on the monitor, just as dots in a magazine picture being smaller and closer together result in a clearer image than the pictures formed by the larger and more spread-out dots in the Sunday comic pages. As a result, the lower the number given in the specifications of a monitor for dot pitch, the clearer the picture it can produce. For example, a monitor with .28 dot pitch, which is measured in millimeters, will produce a higher quality image than a monitor with a .39 dot pitch, since the dots are closer together.
Other terms encountered when evaluating monitor quality are "interlaced" and "non-interlaced." Today’s monitors, just like TVs, produce a picture by sweeping an electron beam across the inside of a picture tube coated with a material that glows when energized by the electrons hitting it. To form a rock-steady picture, the electron "gun" shoots the energizing beam in one direction, say left to right, then turns off on the return trip from right to left, only to turn on again on the next left-to-right sweep to form the next line of the image. However, in order to produce more lines with which to form an image, some monitors cheat and leave the electron gun on all the time, on both the left-to-right and right-to-left sweeps. This results in a slight flickering of the image, which doesn’t bother some people but drives other people crazy. This is called "interlacing" the image. It’s a cost-cutting way to produce a higher-resolution image, albeit with the side effect of a slightly flickering picture. A higher-quality monitor will produce more lines of resolution, but scan them from left-to-right only, resulting in a steadier picture. This is called a "non-interlaced" image. Thus, when it comes to evaluating monitor quality, a "non-interlaced" monitor is better than an "interlaced" one.
Another term I just used is "resolution." This is the actual number of dots forming the monitor’s image. Obviously, the more dots, the clearer the image. In days gone by, various computer video technologies produced images made up of 720 dots across by 350 dots down (720 x 350 pixel resolution), but in one color only (Monochrome Display Adapter, or MDA). Then came monitors with 4 colors, but with only 640 x 200 resolution (Color Graphics Adapter, or CGA), followed by 16 colors with 640 x 350 resolution (Enhanced Graphics Adapter, or EGA).
But enough of this history lesson. Modern monitors and video circuit boards incorporate the VGA, or Video Graphics Array, standard established by IBM when they released their PS/2 line of personal computers in the late 1980s. When first introduced, VGA produced a minimum of 16 colors at a resolution of 640 x 480. Almost immediately, IBM’s competitors developed a so-called "Super VGA" standard of 256 colors at up to 800 x 600 resolution. Today, the VGA standard is sometimes a combination of the two. The most common configuration is 256 colors at 640 x 480 resolution. This number of colors is sometimes called "8-bit," referring to the fact that 2 to the 8th power, or 2 times itself 8 times, equals 256. The next step is 16-bit color, which equals 65,536 colors.
The ultimate configuration today, sometimes referred to as "photo-realistic," is 24-bit color, which equals about 16.8 million colors! Keep in mind that this kind of performance is not only a function of the monitor, but also the video circuit board, or video card, inside your computer’s case producing the image signal. With regard to maximum resolution, it is not uncommon for today’s video card/monitor combinations to be capable of 1024 x 768 resolution or more, resulting in a very clear picture, but with elements such as Windows icons and software pushbuttons being very small.
Needless to say, this type of high-end video capability can be expensive, and probably is only justified if you are a graphics professional dealing with photographic manipulation such as retouching, color correcting, or digital imaging.
What will the future hold with regard to resolution and number of colors? Your guess is as good as mine. I suppose we’ll just have to monitor the situation very closely.
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