Black Levels (black level)

Describes the presence of dark portions in a video image. The black is the absence of light, then to create the black portions of an image display should be capable of extinguishing as much light as possible. The screens with high capacity level of blacks not only produce deeper blacks, but also reveal further details of shadow in dark scenes. The CRT (tube) of high quality have generally improved level of black screen digital plasma, LCD, LCOS DLPy.

In CRT projectors, the light source (electron beam) is turned completely off. In solid-state projectors, the light source (mercury or xenon lamp) is always on. Setting black level correctly is critical to overall picture quality, particularly the ability to see detail in dimly lit scenes of a movie. The term also refers to the ability of a display to produce an inky, deep black, which is often a problem in fixed-pixel displays.

The LCD panels in LCD projectors modulate the light using cross polarizing panels. The panels are not capable of completely extinguishing the light transmission in the off condition. At best, approximately 0.1% of the light is passed thru the panels and projected on to the screen (1000:1 contrast ratio).

Today's high contrast gray screens help to hold black levels solid when there is some ambient or reflected light bouncing from light colored surfaces in the room back onto the screen. But for the best possible image quality for any home theater, take whatever steps you can to eliminate ambient light and reduce the reflectivity of the room's walls and ceiling.