Dynamic contrast ratio is a rating used to measure television image quality. The standard or static contrast ratio of a TV indicates the luminance of the brightest possible white colors on the screen versus the deepness and darkness of black shades. In effect, contrast ratio informs buyers of the range between dark and light colors, which can help buyers to compare picture quality between different units.
Newer televisions often feature a second type of contrast rating, known as dynamic contrast ratio. This ratio measures the maximum possible color range between white and black shades. It requires a special feature within the TV that adjusts the brightness of the display to maximize the picture quality. For example, if viewers are watching a movie with lots of shadows and dark, a processor within the unit increases the brightness to improve contrast. Televisions with this feature can theoretically provide a much higher contrast ratio than standard television models.
Both dynamic contrast ratio and static contrast ratio are expressed using a series of numbers, for example, 500:1 or 1000:1. The larger the difference between these two numbers, the better the picture quality should be. In general, light emitting diode (LED) televisions can provide the highest dynamic contrast ratio because LED's are capable of very bright lighting levels. Many liquid-crystal display (LCD) and plasma televisions also provide dynamic contrast options, though this feature in not available in all models.
Buyers often rely on manufacturer's listings to compare dynamic contrast ratios between different models. Because of variations in measuring contrast, this is not often an effective way to compare different brands, or even models within the same brand. Some manufacturers test dynamic contrast in a controlled laboratory setting, while others test this ratio in a setting that resembles a typical living room. Contrast ratios will always be higher in a controlled setting than they will in uncontrolled environments, making it difficult to compare TV units based on this feature.
In general, televisions with dynamic contrast adjustment produce a better viewing experience. Viewers will notice fewer shadows and better color contrast. As brightness levels adjust, it is also easier to see all of the action on the screen, even in areas of deep shadow. At the same time, some viewers may not like this feature, believing that it brightens or darkens the picture too much. For buyers shopping for a new TV, it's often better to visit stores and compare picture quality instead of relying on contrast ratios and other ratings provided by the manufacturers.