Contrast ratio should be black and white. Taken at face value, it's the ratio of the light level (luminance) the display produces when fed a white signal to the luminance when it's fed a black signal. Unfortunately, it's probably the most misused, inflated, and ultimately misleading specification used to describe HDTVs today.
At the 2009 Consumer Electronics Show, manufacturers quoted contrast ratio specs of 1,000,000:1 or 2,000,000:1 for upcoming LED-based LCD displays (Vizio and LG, respectively), which are similar to the specs quoted by Samsung and Sony for their current LED models. Those numbers sure do sound impressive, but what do they mean in the real world?
Very little. It's true that in general, a higher contrast ratio can indicate that the display produces a deeper level of black, with all of the picture-quality benefits that brings--but then again it might not. Despite the million-to-one contrast ratios of the Samsung and Sony LED sets we reviewed, we observed better black-level performance in the Pioneer PRO-111FD. Pioneer doesn't publish a contrast ratio spec for that television, but has claimed that its black levels are so deep as to be "immeasurable." … Read more