What is contrast ratio?
Contrast is the ratio between the black and white parts within an image. The larger the contrast ratio of an HDTV (or any TV), the greater the difference between the brightest whites and the deepest blacks that TV can display. Therefore, a contrast ratio of 100,000:1 suggests that the black levels are 100,000 times darker than the white levels. But that’s where it should end for most of us–unless you watch everything in the dark, don’t get too caught up in big contrast numbers. They are largely there for show. The way your eye responds to contrast is really the important factor. The presence of even tiny amounts of ambient light in a room can make an HDTV display with a very high contrast ratio look similar to one with a much lower rating.
Dynamic contrast ratio
A notable recent development in the LCD technology is the so-called “dynamic contrast” (DC). When there is a need to display a dark image, the display would underpower the backlight lamp , but will proportionately amplify 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 does contain small areas of superbright light, image quality may be over exposed.
Contrast ratio is of interest in two situations:
1. Cameras: When recording an image (video, film, photography)
2. TVs, Monitors, etc. When choosing or setting up a playback device (TV, computer monitor, etc)
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.
Many industry experts believe static to be the more accurate or trustworthy of numbers since its measurement technique yields more “real world” results than dynamic contrast ratio.
