LCD TV Specification Fact 1 – Dynamic Contrast Ratio & Response Time
Contrast Ratio Comparison Between LCD TV
Many LCD specifications are prone to inflation by the manufacturers or have become largely meaningless. Take contrast ratio for example. That’s the white level divided by the black level, and if you could actually get pure black on any LCD contrast ratio would be “infinity”. In practice, anything over 500:1 is sufficient, and 1000:1 is about the best you can see before the manufacturers start playing tricks. What sort of tricks? How about dynamic contrast ratio, where the backlight intensity changes according to the content currently being shown on the display.
Comparison of Contrast Ratio
Now you can take the maximum white level at maximum brightness and divide it by the minimum black level at minimum brightness, which results in substantially higher contrast ratios. Unfortunately, in practice the varying intensity of the backlight can be distracting to say the least, and color accuracy greatly suffers because of the constantly shifting brightness levels. Our advice: ignore dynamic contrast ratios, and if your display supports the feature we recommend disabling it.
Pixel response times are another area that has been inflated — or deflated in this case. We have looked at various LCDs boasting anywhere from a 2ms to 16ms response time; honestly, we would be hard-pressed to tell the difference between most of them. All of the comparison images we’ve captured show similar best/worst case scenarios for pixel response latency, with one or two afterimages present. A bigger problem these days is processing lag (aka “input lag”), which is the delay between the time a signal is sent to your LCD and the time the internal circuitry finishes processing it and actually shows it on the LCD panel. We have measured lag as high as 50ms, which makes gaming very frustrating and is even noticeable/irritating during general Windows usage.
