contrast ratio

(redirected from contrast range)
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contrast ratio

[′kän‚trast ‚rā·shō]
(electronics)
The ratio of the maximum to the minimum luminance values in a television picture.

contrast ratio

The ratio of the reflectance of a dry paint film over a black substrate having 5 percent reflectance or less, to the reflectance of the same paint equivalently applied over a substrate having an 80 percent reflectance.

contrast ratio

The ratio of the brightest white to the darkest black on a TV or computer monitor. The larger the number, the greater the extremes; for example, car headlights can appear brilliant next to the pitch black of the night sky. Contrast ratio is an important criterion in screen quality.

White Divided by Black
The ratio is derived by the brightest luminance divided by the darkest luminance in candelas per square meter (cd/m2). For example, if white is 98 cd/m2 and black is 0.02, the ratio is 4900:1. In the 2013-2014 time frame, and using the same testing method, LED TVs have been measured with contrast ratios from 700:1 to 7500:1.

Following are two of many measurement methods; however, contrast ratios are known to be "invented" because vendors can apply a technique in different ways to come up with higher numbers. One bogus approach is to adjust the TV white level to settings the viewer would never really use.

ANSI Contrast and Full On/Off
ANSI Contrast uses a checkerboard of alternating black and white squares, and the average white output is divided by the average black output. The test may be done by calibrating the white to 100 cd/m2 and then measuring the black.

Full On/Off measures an all-white screen with an all-black screen and always produces a higher ratio than the ANSI Contrast. See LED TV, Dolby HDR and dynamic contrast.
References in periodicals archive ?
The Advanced SF filter not only maintains the highlights and shadowed areas of the image, but also opens up the overall contrast range so that a greater degree of tonal values can be rendered in the final image.
Analyzing the lightest and darkest areas on the screen and extending the dynamic range without loss of detail in bright or dark areas, High Dynamic Range creates a contrast range with true-to-life intensity, more accurately reproducing the nuances of the picture and revealing fine details found in real scenes.
The Enhanced position expands the overall contrast range in the picture, resulting in richer, deeper blacks, finer tonal gradation and gray scale reproduction.
As soon as I did testing of the F65, I was immensely impressed by the amount of detail it captures, by its incredible flexibility, from low lights to high lights, and its great contrast range.
We had to adjust the contrast range of our lighting to that of the camera, which was a bit more limited than the dynamic range of film, but once done, all went quite well.
Now that we've increased the number of our panel's displayable colors from eight billion to nearly 29 billion with 3072 shades of gradation and upped our maximum contrast range from 3,000:1 to 10,000:1 to achieve the blackest blacks and whitest whites in the industry, we feel very confident of retaining our top ranking with both HDTV plasma buyers and the consumer electronics media.