显示器的图像复制能力主要取决于亮度（luminance)和色域范围(color gamut)。

A display that can combine both high luminance and a high-percentage color gamut should provide the best image-reproduction capability.

Considering the big difference among the built quality among the different monitors, they are not always reproduce image faintfully. Calibration is primarily used to fix problem on professional equipments.

Most standalone LCD monitor already has high enough luminance. However, some middle to low end laptop has limited luminance for their LCD screen. This will be worse when its running on battery, because manufacture tried to lower brightness so the battery life span can match that as they claimed. Lucky, most time you can override the brightness in BIOS or somewhere; but don\'t expect to be as good as standalone\'s.

Color space is usually referred as the percentage of NTSC color gamut(101% of aRGB and 139% of sRGB). CRT and most LCD has about 72% of NTSC color gamust. Some new model (e.g. Dellxxxx WFP-HC and some Apple monitor) is claiming 92%, which definitely shows more color on your screen.

Ref:
http://www.ipctechnology.com/support/techinfo/color_gamut.htm