Video Modes, Colors and Resolution

Most video cards have several different operating modes. Each mode has a different resolution and different number of colors. For example, the most basic mode in Windows is mode called "VGA" which has a resolution of 640 by 480 and 16 colors. This means that the display has 640 pixels horizontally, 480 pixels vertically and can display no more than 16 colors at one time. Other common resolutions include 800x600, 1024x768 and 1280x1024. Other common color modes include 256 colors, 65,536 colors and 16 million colors.

Effects Of Video Modes. Higher resolution and more colors give better-looking images. However, different resolutions can have other effects.

1. Speed. Some video cards run slower when you run at higher resolution or use more colors. This is usually not a problem with the latest “hardware accelerated” cards, but it can be a problem with older display adapters.

2. Image Size. Using higher resolutions cause various objects on the Windows screen to appears smaller. In the case of the Viewer, the resolution will effect the size of Scale Bar in the Legend. For these reasons, the video resolution is usually tied to the size of the monitor. For example, 640x480 resolution is usually used on 15-inch monitors, while 800x600 is usually used on 17 inch monitors.

Setting Video Modes. You can change your video mode by going to "My Computer" and opening the "Control Panel." Select the "Display" option and the "Settings" page. Some video cards also provide special tools that reside in the System Tray and make it easier to change video modes.