Save wear and tear on your eyes: Buy the right video display

Personel computers

April 27, 1992|By Michael J. Himowitz | Michael J. Himowitz,Staff Writer

The most important part of your computer system is the part you stare at.

A fast processor, lots of memory and a huge hard disk won't

make you happy if you have to spend hours staring at a monitor that's fuzzy, badly aligned or not matched to your eyes or the work you do.

Some buyers spend hundreds of dollars extra for video capacity they don't need. Others look for bargains that turn out to be very expensive in terms of wear and tear on their eyes.

Unfortunately, ads for computer systems, monitors and video boards are shrouded in technobabble. But it's not too hard to understand the basics, ask the right questions and buy a video display that's right for you and your pocketbook.

First things first. The image displayed on your screen is the product of four things: your monitor, the video circuitry board inside your PC, the software you're using and your brain. You can mix and match all but the last to get the combination you need.

Most IBM-compatible computers on the market today come with some type of VGA monitor and video board. VGA is an acronym for IBM's Video Graphics Array, the circuitry that first appeared in the company's PS/2 systems four years ago.

Standard VGA circuit boards and and monitors produce an image with a maximum resolution of 640 by 480 pixels, with 16 colors. That means the system divides the screen into a grid 640 dots across by 480 dots down. Each pixel can be one of 16 colors.

In some graphic and game modes, VGA cards can also produce a resolution of 320 by 200 pixels with 256 colors. Although the image isn't technically as sharp as 640 by 480, the additional colors can fool the brain into thinking it's seeing a near-photographic reproduction.

The VGA combination produces well-formed, readable text in normal DOS applications, and it's acceptable for basic graphics applications, including the Microsoft Windows graphic environment. In addition to the standard 80-character by 24-line display, VGA boards can produce normal text in 43 or 50 line modes (with correspondingly squished looking characters).

If all you're doing is running Word Perfect or Lotus 1-2-3 under DOS, a standard VGA setup will probably do just fine. The important thing is the quality of the monitor (more about that later).

For those who need higher resolution -- including folks who do extensive desktop publishing, photo scanning or other high-end imaging -- there are a variety of Super VGA (SVGA) monitors and video boards available. These often come as standard equipment on new systems today.

The most common SVGA monitors and video boards offer resolutions of 800 by 600 or 1,024 by 768 pixels, with 256 colors, although exotic and expensive combinations of boards and monitors can produce higher resolutions with as many as 16,000,000 colors.

The problem is that IBM never set a standard for Super VGA, so most makers of VGA circuit boards have to provide special software programs, called drivers, to let programs such as Windows, WordPerfect or Lotus take advantage of the additional resolution. If your software doesn't support SVGA, you won't get additional benefits from it.

Also, not all SVGA monitors are equally capable of delivering resolutions higher than 800 by 600 pixels. The important thing here is the refresh rate, the number of times per second the circuitry redraws the screen.

Less expensive monitors with slower refresh rates use a device called interlacing -- drawing every other line with each pass of the electron gun -- to produce higher resolutions. This produces annoying flicker. A non-interlaced monitor is more expensive, but a must if you spend a lot of time at higher resolutions.

Unfortunately, many people buy high-resolution monitors thinking they'll actually get a sharper, more realistic display using Microsoft Windows, desktop publishing or other graphics programs. They're inevitably disappointed.

"All I get is a smaller image. I can barely read it," is a typical complaint.

Here's the reason: When a program such as Microsoft Windows draws its windows or text on a screen, the lines and characters are defined as a certain number of pixels. If a box is 640 pixels wide, it will occupy all of a standard VGA screen, but only 80 percent of an 800 by 600 SVGA screen and only 60 percent of a 1,024 by 768 screen.

This makes reading text at higher resolutions an iffy proposition on standard 14-inch monitors. A character that's a comfortable size in standard VGA mode will be only 80 or 60 percent as large in higher-resolution modes. My forty-something eyes call it quits after 800 by 600.

So what good is higher resolution? It has some advantages. For example, desktop publishing programs will show you a larger portion of a page without distorting text when you use higher resolution, and you can enlarge the image for normal editing.

But if you really want to take advantage of SVGA modes and be able to read documents without straining or playing software tricks, you'll need a monitor with a larger screen -- a 16- or 19-inch model.

Unfortunately, these are break-the-bank propositions. While you can get a decent 14-inch monitor for $300 to $500, larger 16-inch monitors start at close to $1,000, and 19-inch models, used primarily by graphic artists, run anywhere between $1,500 and $4,000.

No matter what kind of monitor you settle on, make sure the image is sharp and crisp at the resolution you'll be using. The best measurement of this is the monitor's dot pitch -- the distance between the center of adjacent pixels. If the dot pitch is too coarse, you'll get fuzzy text and graphics.

Buy a monitor with a .31 millimeter or .28 mm dot pitch. Many bar gain basement clone makers cut corners by providing coarse, .42 or even .51 mm models. If it costs more to trade up to a better monitor, it's the best money you'll spend.

Most important, don't buy a monitor or system you haven't tried out. In the end, no matter what the price tag or monitor specifications say, your eyes are the ultimate judge.

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