Article: Improve Your Image: 13 Simple LCD Graphics Tweaks

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http://www.pcworld.com/howto/article/0,aid,124858,pg,1,00.asp

Kirk Steers
From the May 2006 issue of PC World magazine
Posted Friday, March 17, 2006

Improve Your Image: 13 Simple Graphics Tweaks

Some small adjustments to your LCD monitor can make a big difference in picture quality.

Think about this: You spend almost as much time in front of a computer monitor as you do sleeping. Shouldn't you do everything you can to make your viewing as comfortable and trouble-free as possible? If you've recently upgraded to an LCD monitor, you should know that tuning one of these devices is not the same as tweaking a CRT display's settings. Although the following tips focus primarily on LCDs, many of the settings and steps apply equally to CRTs.

No matter what type of monitor you're using, much of the quality of the image it shows depends on your computer's graphics card or chip set. Start by making sure you have the latest version of the driver for your graphics adapter; this is one of the easiest and most effective ways to optimize your graphics and avoid hardware hassles.

Don't bother using Device Manager's Update Driver option, which works fine for other drivers but is useless for updating your video card's software. Instead, browse to your graphics card vendor's Web site, look for a "Downloads" or "Support" link, and find the driver for your card's make and model. Stay away from beta versions of drivers that may be listed on the manufacturer's Web site. These are works in progress that are an invitation to troublesome PC behavior.

You configure your graphics card or chip set through Windows' Display Properties: Right-click the desktop and choose Properties to open this dialog box. The settings that you'll see vary from system to system and are determined by the installed driver, but all graphics adapters offer several important settings:

Screen resolution: On CRT monitors, the screen resolution--the number of dots, or pixels, that run vertically and horizontally across your screen--is scalable; you can raise or lower resolution settings without affecting image quality, so you can pick any supported resolution that pleases you. The same isn't true for LCDs, however, as they have a fixed number of pixels that define the display's native resolution. You'll see the monitor's best-looking, full-screen images only when it is set to that resolution.

Most 15-inch LCDs have a native resolution of 1024 by 768 pixels, while 17- and 19-inch LCDs usually are 1280 by 1024. Any setting lower than the native resolution results either in letterboxing, which maintains image quality by shrinking the image to a compatible size, or interpolation, which keeps a full-screen image but adjusts for missing pixels, often sacrificing image quality as a result. The exception is when the lower resolution is half the native resolution, such as 800 by 600 pixels for a native resolution of 1600 by 1200; in this case, the resulting image is neither letterboxed nor interpolated.

Even though some LCDs have scaling algorithms that do a good job of smoothing images displayed at nonnative resolutions, you should always set the monitor to its native resolution. To do so, click the Settings tab in the Display Properties dialog box and adjust the slider under 'Screen resolution' (see Figure 1). Assuming Windows has properly detected your monitor, the native resolution will be the highest resolution available to you.

Color quality: The more colors your monitor shows, the more realistic its images. Most PCs have the power required to support the highest setting, usually labeled 32-bit. But if you're experiencing sluggish graphics performance (especially if your PC uses system RAM for both graphics and standard computing duties, as many low-cost machines do), reduce the color setting to speed things up.

Refresh rate: The annoying screen flicker of many CRTs is due to a refresh rate that's set too low. (Images on a CRT are constantly redrawn, or "refreshed," by an electron beam that zigzags across the screen.) Conventional wisdom says a CRT needs to be refreshed more than 72 times per second, or 72 Hz, to avoid causing eyestrain. Experiment to determine the setting that works best for you and your eyes; this may not be the highest setting the monitor supports.

With LCDs, screen flicker isn't an issue because the devices don't refresh the entire screen, just the pixels that change. A refresh rate of 40 to 60 Hz should be fine for an LCD, unless its manufacturer says otherwise. What may be an issue to some LCD users, and especially gamers, is the pixel response time of the display, which is the time a single pixel requires to change from black to white and then back to black. Older LCDs have pixel response times slower than 20 milliseconds, which leads to ghosting of rapidly moving images. Most LCDs sold today are said to be faster, but before you buy an LCD for gaming, read Laura Blackwell's "LCD Specs: Not So Swift."

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Monitor Makeover

Whether your monitor's an LCD or a CRT, don't be afraid to experiment with its controls. The right settings are the ones that look best to you, not the vendor's (or anybody else's) recommendation. You'll usually access the settings via buttons or knobs on the monitor bezel.

LCDs tend to be easier to tune than CRTs. You rarely need to adjust an LCD screen up, down, left, or right to fit it edge to edge, as you often must with a CRT. Also, many LCDs have a single button or setting that automatically tunes and positions the on-screen image. And finally, LCD monitors usually require few color or contrast adjustments when they're set at their native resolution.

Here are the settings you'll find on most LCDs, and how to adjust them. Note that the names of settings vary from one make and model to another.

Brightness and contrast: The brightness setting controls the intensity of the backlights on the display. LCDs tend to be much brighter than CRTs, so increasing the brightness may not be necessary or desirable. Adjust the contrast using a grayscale chart such as the one in the free DisplayMate program to maximize the number of viewable shades of gray. LCDs often lose detail at the dark end of the scale.

Color tone or color temperature: Different light sources emit slightly different tints of "white" light, from a cool bluish-white to a warm reddish-white. Most monitors offer at least three tones, or temperatures, to accommodate various lighting conditions. These settings may be labeled Mode 1, Mode 2, and Mode 3, or High, Medium, and Low. They may also use scientific labels that refer to the temperature in degrees Kelvin (K) at which superheated objects emit that color of white light. Common settings include a bluish 9300 K, a more neutral 6500 K, and a reddish 5000 K. Many monitors let you manually select the balance of red, blue, and green in your white light. Tweak the settings to see what temperature suits you.

Information: This setting is included on some LCDs to tell you the current screen resolution, as well as the number of hours the display has been in operation and the number of hours that the backlight has been burning--nice statistics to know if you're buying a used LCD.

Horizontal and vertical positions: These settings allow you to center the screen image manually; however, most LCDs come with either an auto-tune button or other automatic position adjustments that should obviate using these manual controls.

Pixel clock and phase clock: These two settings appear under a number of names (including "coarse"/"fine-tune"), but they're usually listed with the image or picture controls. If you're stuck with an analog VGA connection that's acting up, tweak these settings manually rather than relying on the auto-conversion to correct so-called swimming pixels.

A few last points: Windows XP's ClearType font-smoothing technology will sharpen the text on an LCD. Click the Appearance tab in the Display Properties dialog box, select Effects, check Use the following method to smooth screen fonts, and click ClearType from the drop-down menu (see Figure 2). For more ClearType controls, try Microsoft's ClearType Tuner PowerToy.)

DirectX is a Windows technology that enhances graphics and sound. Learn whether you have the latest version (currently 9.0c) via the DirectX Diagnostic Tool. Click Start, Run, type dxdiag, press , and look under the System tab for the version (see Figure 3). You can download the latest DirectX version from Microsoft.

If possible, use DVI to connect your LCD to your computer. Such digital connections produce better images than a CRT's analog VGA link. If your LCD supports DVI but your PC's graphics adapter has only VGA ports, consider an upgrade; DVI-equipped graphics cards cost less than $50 online. If your images are too dark even at your monitor's highest brightness, experiment with the gamma setting in Windows' Display Properties. (Check the ATI or nVidia tab under Display Properties, Settings, Advanced.)

First Aid for Your LCD

LCDs are easier to maintain than CRTs, but they still break on occasion. Here are two common problems related to LCDs, and how to fix them.

Blank screen: If the Power On light is illuminated but there's no picture, check the connection between the device and your PC to make sure it's receiving a video signal. If the cable is snug at both ends, connect a different monitor to your PC to ensure that both the cable and the PC's graphics card are good. If the second monitor shows an image, the backlight in your LCD may be dead (this is the most common cause of failure). A local computer shop can replace your backlight--or, if you're savvy, you can replace it yourself, although finding the right backlight and doing the actual replacement can be difficult. Before you go this route, research prices to determine whether buying a new display wouldn't be more cost effective.

Permanently pesky pixels: Most LCD manufacturers expect some bad pixels in their products and require a certain number of bad pixels--typically between three and ten--before they even consider the display defective. Check your LCD for bad pixels immediately after you connect the display for the first time. If you don't like what you see, try to exchange the monitor for a new one--in some cases, though, you may not be able to do so.