The appearance of the image on your monitor's screen is controlled by the Windows Display Settings dialog box, the configuration program supplied with your graphics card, and also by the settings on the monitor itself. There's no standard location for the monitor's controls, but they're usually on the bottom of the frame that surrounds the display screen or along the edge of the frame. The specific set of controls changes from one make or model of monitor to another, so the best source of information about your own monitor is the instruction manual supplied with it (it you don't have one, look for a copy on the manufacturer's Web site).
Most monitors include controls that use on-screen menus and pushbuttons to change settings. Others can use software that allows a user to adjust the monitor with the computer's keyboard and mouse. Many of these controls are often awkward and somewhat confusing to use, but fortunately, most people don't have to change the monitor settings very often.
The most important monitor controls include:
Brightness: The brightness control on an LCD sets the overall intensity of the monitor's backlight. The monitor's brightness is set correctly when black parts of an image appear as a true black.
Contrast: Contrast is the difference between foreground and background items, or the difference between pure white and pure black. It's best to set the brightness first, and then adjust contrast, because you can produce a greater range of contrast on a brighter screen.
Horizontal position: The horizontal position control moves the overall image to the left or right. Use this control if the image extends beyond the edge of the screen, or if there's a black line between the image and the screen's edge.
Vertical position: The vertical position control moves the image up or down.
Horizontal size: The horizontal size control increases or decreases the width of the image on a CRT screen. Use this control and the horizontal position control to center the image and fill the screen all the way to the right and left edges of the screen.
Vertical size: The vertical size control increases or decreases the height of the image on a CRT screen. Use this control with the vertical position control to center the image vertically.
Color temperature: The color temperature of your monitor specifies the relative warm (red) or cool (blue) level of the monitor's color balance. It has nothing to do with the thermal temperature of the monitor. The correct setting for your monitor depends on the spectral balance (the relative amounts of red, green, and blue light) of the other light sources in the room and your own personal preference. Most monitors offer two or more preset color temperature settings, either from the on-screen controls on in software. To set the color temperature, open the Windows Notepad program to display a window with a white background (Start Programs All Programs Accessories Notepad), try each of the monitor's preset values, and choose the one that produces the best-looking white background in the Notepad window.
Geometry: The shape of the image on a CRT monitor screen can become distorted over time, so the monitor's controls offer settings that can correct the most common problems. When all of the geometry controls are set correctly, the lines on a grid should all be parallel, and the horizontal and vertical lines should be at right angles to one another.
The most common geometry settings are
Pincushion: The pincushion control compensates for an image that is wider or narrower in the middle of the screen than at the top and bottom, like the shape of a pincushion.
Trapezoid: The trapezoid control fixes images in which the top of the image is wider or narrower than the bottom.
Parallelogram: The parallelogram adjustment corrects images in which the top of the image is shifted to the left or right of the bottom.
Rotate: The rotate control shifts the image when the whole image is not absolutely vertical.
Figure 11.3 shows the shapes that each geometry setting corrects.
Figure 11.3: The geometry controls correct distorted shapes on monitor screens.