Dynamic Contrast (DC)
A notable recent development in the LCD technology is "dynamic contrast" (DC), also called "advanced contrast ratio" (ACR) and various other designations. When there is a need to display a dark image, a display that supports dynamic contrast underpowers the backlight lamp (or decreases the aperture of the projector's lens using an iris), but proportionately amplifies the transmission through the LCD panel; this gives the benefit of realizing the potential static contrast ratio of the LCD panel in dark scenes when the image is watched in a dark room. The drawback is that if a dark scene contains small areas of superbright light, the resulting image may be over exposed.
The trick for the display is to determine how much of the highlights may be unnoticeably blown out in a given image under the given ambient lighting conditions.
Brightness, as it is most often used in marketing literature, refers to the emitted luminous intensity on screen, measured in candela per square metre (cd/m2). The higher the number, the brighter the screen.
It is also common to market only the dynamic contrast ratio capability of a display (when it is better than its static contrast ratio only on paper), which should not be directly compared to the static contrast ratio. A plasma display with a 2,000,000:1 static contrast ratio will show superior contrast to an LCD (with LED or CCFL backlight) with 30,000,000:1 dynamic and 10,000:1 static contrast ratio when the input signal contains a full range of brightnesses from 0 to 100% simultaneously. They will, however, be on-par when input signal ranges only from 0 to 20% brightness.
Read more about this topic: Contrast Ratio
Famous quotes containing the words dynamic and/or contrast:
“We Americans have the chance to become someday a nation in which all radical stocks and classes can exist in their own selfhoods, but meet on a basis of respect and equality and live together, socially, economically, and politically. We can become a dynamic equilibrium, a harmony of many different elements, in which the whole will be greater than all its parts and greater than any society the world has seen before. It can still happen.”
—Shirley Chisholm (b. 1924)
“Unlike Boswell, whose Journals record a long and unrewarded search for a self, Johnson possessed a formidable one. His life in London—he arrived twenty-five years earlier than Boswell—turned out to be a long defense of the values of Augustan humanism against the pressures of other possibilities. In contrast to Boswell, Johnson possesses an identity not because he has gone in search of one, but because of his allegiance to a set of assumptions that he regards as objectively true.”
—Jeffrey Hart (b. 1930)