Backlighting and spill

[hassen1]

Notebook screens have adjustable brightness, mainly to conserve power, but the brightness adjustment actually adjusts the intensity of the backlight - a light inside the panel that illuminates the screen. The screen consumes a substantial amount of your notebook's power, so adjusting the brightness to a lower setting can save a lot of battery life.

However, backlighting isn't always even and sometimes the source of the light can be seen (usually on the bottom). This is called spill. Some less expensive notebooks (and even some more expensive ones, like Dell's Inspiron 9300 line) have some problems with spill, where a portion of the screen might be noticeably brighter than the rest (though never by too much). Spill is most noticeable when the screen is black.

[mini_0]

Color spill typically happens near the edges of object silhouettes because the Fresnel effect increases the secularity of materials near grazing angles. With a single color active backlight, spill is particularly prominent for highly specular surfaces, such as shiny metals or ceramics.Nevertheless, it is still possible to observed spill errors for highly specular objects.