Number 239 - April 2003

Buying a Monitor?
by Charlie Semple and Herb Van Brink, LACS
Prepare yourself. There's such a wide variety that arming yourself with knowledge will help avoid costly errors and save you time.    Decisions, decisions. How large a unit can your space accommodate? Should you get a conventional CRT (like TV) or should you get one of the new LCD (liquid crystal display) types? First be sure you understand the terminology. There are some other considerations but let's keep it simple. CRT Monitors - (Cathode Ray Tubes)    CRT monitors (or "displays", as they are technically called) can be bulky and heavy, use significant electric power and produce noticeable heat. CRT monitors today commonly use 0.25 or 0.26 mm. dot pitch (the spacing between the centers of the dots on the screen). Inexpensive CRT monitors may use 0.29 mm. dot pitch and the image is not as clear as monitors with a smaller d.p. The smaller the number, the closer together the dots (pixels) are, thereby providing better definition of an image on your screen.    LCD Displays - (Liquid Crystal Displays)    LCD displays are usually thin (front to back) and only moderately heavy , compared to CRT displays -a consideration when moving stuff around, and they don't produce much heat.    LCD displays today are mostly TFT (thin film transistor) (otheIWise known as "an active screen ") type instead of the older passive displays. Producing LCD displays with small dot pitch is more costly than with larger d.p. You will find that most of the inexpensive LCD units use d.p. 0.28 or larger. Interestingly, in most cases these are very adequate for general use. LCD's with smaller d.p. can be helpful when doing a lot of detailed graphic work or CAD (computer aided design) such as architectural or technical drawings.    LCD Brightness is a consideration. Many of the inexpensive LCD's have a brightness (average) of 200 cd./sq. meter. That is 200 Candelas. As the unit ages, this number decreases and the screen becomes increasingly difficult to see in a lighted room. 250 cd./sq. meter is probably a good minimum to start with. More are better (and more expensive). Digital Vs. Analog:    Usual LCD displays are analog and most people find them quite satisfactory. Digital displays are less prone to "shimmering" or flicker, which is noticed by some people but not others. If you choose a digital display usually a special video card must be installed in your computer.    FLAT SCREEN - CRT monitors may be "flat screen " or not. Remember that it is a large vacuum tube and a "bulbous" screen is the conventional technology .LCD displays are inherently "flat screen". Other Considerations    Here are some of those "other considerations" that you may also find helpful: What do you do most? (If mostly e-mail or plain text documents, who cares? Almost any monitor will do.) If lots of detailed image processing, you'll want a monitor with high resolution capability -working on pictures at 800x600 is an exercise in futility -for the higher resolutions, bigger monitors are better -You'd hate to look at a 1600x1200 display on a 14" monitor. (Because a lot of windows simply counts pixels instead of adjusting for actual size -so with higher resolutions, your icons and other images get smaller)    Screen Resolution    Some Commonly used Screen Resolutions: VGA 640 pixels x 480 pixels, SVGA 800 x 600, XGA 1024 x 768 and SXGA 1280 x 01024"	Don't just look at the monitor demos in the store. Look at something that's like what YOU use it for. You might bring along one or two of your own files on a floppy and run them on the demo monitors. ALL monitors look good when showing movies of bright yellow flowers with red centers against a navy blue sky with brilliant white clouds. Controls    How adjustable is it? Can you easily change the contrast, brightness, centering, screen coverage? On-screen adjustments by using buttons on the monitor are more common now than the row of adjustment knobs we used to see under the front edge of earlier monitors.    If you have vision problems, some monitors have special features like push-button magnification or high-contrast, but this can also be done -easier and cheaper -with software. Sound    Some monitors have built-in speakers. While the sound is not as good as from separate speakers, it could free up some space on or under your desk.    Some monitors have USB ports in front or at the side. The wires might get in your way, but that could be easier than connecting things in back of the computer. Quality    How GOOD is it as a monitor? This is hard to describe, but it includes things like pincushioning and barreling, consistent clarity in all portions of the screen, etc.). These factors can be very important in architectural work or engineering drawings etc. Refresh Rates    Faster refresh rates reduce the probability of noticeable flicker and put images on your screen faster. You may or may not notice the difference.    For LCD's, how wide is the easily readable viewing angle? A wide angle of view is important if more than one person is often looking at the screen at the same time very often. (Tell me that you don't say "Come over here and look at this!") Or if you move around a lot while working at the computer -leaning over to peck a few keys now and then. Video Card    Does your video card (or onboard video circuitry) support the monitor you're looking at? Adding a new top-of-the-line monitor doesn't help if you've got a 1989 graphics video card and you are not be able to update it.. Digital vs. Analog Control    In addition to digital vs. analog LCD's, there's a digital control vs. analog control applicable to all monitors. Analog control monitors need to be manually readjusted whenever you change modes. Digital ones remember the settings for each mode. On the other hand, how many people change their resolution frequently? (Some of us do it a lot more than most, and it's probably once or twice a month). The cheapest monitors are analog only. Flat Vs. Conventional Screen    Choosing a flat Screen monitor instead of a conventional screen seems mostly to be a matter of preference. Some people contend that flat screen images are less distorted. Others prefer the better ability to manage reflections by using a flat screen.    Good luck. We hope that this information helps you make a good choice.
Number 239 - April 2003