The Truth About Contrast Ratios

What is contrast ratio? It is the ratio of the bright level to the black level. Pretty simple. But it really isn’t. Wikipedia defines contrast ratio as: “the ratio of the luminance of the brightest color (white) to that of the darkest color (black) that the system is capable of producing.” According to an article by David Katzmaier at crave, the contrast ratio specification is “probably the most misused, inflated, and ultimately misleading specification used to describe HDTVs today.” Let’s see what’s up.

In general, a higher contrast ratio means better quality images on your TV. A higher contrast ratio can be achieved by doing one of three things: make blacks darker, make whites brighter, or do both. For years and prior to Pioneer‘s KURO technology, FPD (flat panel display) manufacturers have tried to improve contrast ratio by making it brighter. This is pretty easy to do: shove in more CCFLs and you get brigther screens. What Pioneer did with its KURO technology was to make blacks really dark. Tests, testimonials, reviews, previews, etc. have all shown that the KURO technology is the one to beat. Pioneer doesn’t even state a contrast ratio specification because the company says it is impossible to measure.

Speaking of measuring contrast ratio there is no standard method. Companies are left to their own devices to measure contrast ratio:

  • Full-white screen versus a full-black screen.
  • Focus all wattage to a single pixel to measure white.
  • Turn the display completely off to measure black.
  • Pull something out of your butt.

But there is one method that could become the standard way of measuring contrast ratio: ANSI contrast ratio measurement. The ANSI method uses a checkerboard of eight white and eight black rectangles and averages the brightness of the white and black rectangles. The ratio between the two averages become the contrast ratio: nice and simple. So why don’t the TV folks use the ANSI method of determining contrast ratio? Probably because the numbers will be so miniscule. Miniscule = Not good for marketing. Marketing wants MILLION to one or TWO million to one. Not small; BIG.

ansi_checkerboard

I say TV manufacturers be strongly urged by the US government to use a standard method of measuring contrast ratio (e.g. ANSI). Consumers are confused by these numbers and are in some cases duped into thinking that one TV is better than another because of the specification. Although I will continue to put contrast ratio specifications make sure to remember that those numbers don’t mean as much as you think.

There are many articles on contrast ratio and here are some that you might enjoy:

Source: crave

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