THE MONITOR

When you think about it, you will realize that you spend most of your time looking at the video monitor when working at your computer. Again, inexpensive monitors accompany inexpensive computer systems. A good monitor yields a crystal clear image and is flicker-free. Often you won't notice any inherent flicker from the monitor when glancing at it for a short period of time. However, after hours of work, the subconscious mind processes this subliminal flicker and translates it into eye strain or a major headache!
Better monitors can be set with higher refresh rates to eliminate flicker. A slow refresh rate of less than 60 Hz can be irritating. Your eyes will thank you if your monitor has a refresh rate of 70 Hz-100 Hz. Of course, your video graphics card must also have the capability of supporting higher refresh rates.
A good video card and a good monitor constitutes a good video subsystem. Inexpensive computers have video subsystems that are plagued by slow performance, unsharp displays with inherent flicker, and poor convergence of colors that creates a halo around text and graphics. Skimping on this aspect of your computer purchase will take its toll on you, especially if you use the computer for extended periods.
Bargain computers usually come with 14" monitors. A 15" monitor is far superior. You may find it hard to understand how 1" can make such a big difference. The only way to answer this is, "seeing is believing". Check out two identical computers hooked up to 14" and 15" monitors. You'll only want to buy the 15".
Monitors display images by way of tiny dots on the screen, much as newspaper images consist of tiny dots. The finer the dots, the better the image looks. A monitor with a dot pitch of 0.35 mm will look coarse and grainy compared to a monitor with 0.28 mm dots. These dots are called picture elements or pixels for short.
Better video subsystems let you vary the number of pixels on the screen. The standard number of pixels or dots is 640 across the screen and 480 from top to bottom. Therefore, a standard screen will display 640 x 480 or 307,200 pixels.
If you purchase a larger monitor, say a 17" size, a resolution of 640 x 480 may appear a little too coarse. Most people like a resolution of 800 x 600 pixels on a 17" screen. This is 480,000 pixels and it gives the video display a pleasing look.
For specialized publishing and drawing applications, many businesses use a much larger 21" monitor. With such a large monitor, 800 x 600 pixels looks rather coarse. Therefore, 21" screens are typically set for 1,024 x 768 or 786,432 pixels. Some are set even finer, to 1,280 x 1,024 or 1,310,720 pixels.
Please remember that these variable settings are only possible if the monitor and video display card allow them. The greater the number of pixels, the higher the resolution. You could purchase a good video display card and high quality 15" monitor and set your screen to display 1,280 x 1,024 pixels. However, if you did this, the text on the screen would be so small that you would need a magnifying glass to read it. Clearly there are optimal settings for every size of monitor.
There is another important consideration when dealing with video displays. It is the number of colors on the screen a one time. Early computers could display only 16 different colors at one time. Later, the industry standard became 256 simultaneous colors. Today, the standard is 16,777,216 simultaneous colors! With over 16 million colors to choose from, the screen can display photo-realistic images that are every bit as good as what you are accustomed to viewing on TV.
We refer to the 16 million colors as a true color palette. Video monitors never use all 16 million colors at once. Think about it. If the monitor is set for 640 x 480 or 307,200 pixels and every single pixel is a different color, the video display would only be using about 2% of the 16 million possible colors! Even if the screen resolution was set for 1,280 x 1,024 or 1,310,720 pixels and every pixel was a different color, the video display would still only be using about 8% of the total true color palette.
You may have heard that video images are only made up of three primary colors, Red, Green, and Blue (referred to as RGB). In every pixel, each of these colors is stored in 1 BYTE. So the color of a single pixel requires 1 Red BYTE, 1 Green BYTE and 1 Blue BYTE. Remember, a single BYTE can represent any of 256 possible conditions. So there are 256 possible shades of red, 256 possible shades of green, and 256 possible shades of blue. The total number of possible combinations is therefore 256 x 256 x 256 or 16,777,216 colors!
To summarize, it takes 3 BYTES to store a true color in any pixel.
For a 640 x 480 true color screen, you need video memory of 640 x 480 x 3 BYTES = 921,600 BYTES
For an 800 x 600 true color screen, you need video memory of 800 x 600 x 3 BYTES = 1,440,000 BYTES
For a 1,024 x 768 true color screen, you need video memory of 1,024 x 768 x 3 BYTES = 2,359,296 BYTES
For a 1,280 x 1,024 true color screen, you need video memory of 1,280 x 1,024 x 3 BYTES = 3,932,160 BYTES
It was mentioned earlier that inexpensive computers today typically come with 1 MB video display cards. A 1 MB card is only sufficient for displaying a 640 x 480 true color screen. It would not be capable of displaying an 800 x 600 true color screen because this requires more than 1.4 MB of video RAM. To display this, you would need a 2 MB video card. You can see why the bargain computer has limited display options. The better computer comes with 4 MB of video RAM on the video card which easily allows a true color display at the higher 800 x 600 resolution.
So what happens if you attempt to change the screen resolution to 800 x 600 and you only have a 1 MB video card? This can be done, however, you cannot access a true color palette of 16,777,216 colors. Instead, the video card sets a new color depth - a reduced palette of only 65,536 colors. These images still look quite good, however subtle tonal gradations will be poorer. If you try for higher resolutions like 1,024 x 768, the color depth will be reduced even further, to only 256 colors. Surprisingly, 256 color images can still look quite good. Of course, they don't always have the photo-realistic look of true color images.
We have spent a lot of time discussing video imagery here. It's very important to purchase a video card with expandable video RAM, highly accelerated performance, and the ability to adjust screen resolution and color depth. Likewise, your monitor should be capable of working at a variety of resolutions. It must support refresh rates that eliminate flicker at all the resolutions you choose to use.
A final note on monitors. Because monitors emit electromagnetic radiation, it's better to pay a little more and get one that's properly shielded. Today's monitors should be ENERGY STAR compliant. This means they have built-in circuitry to automatically shut down when the computer is not being used for an extended time (say 10 minutes). As soon as you touch the keyboard or mouse, the monitor turns itself on automatically.