contrast ratio


Also found in: Dictionary, Thesaurus, Medical, Wikipedia.

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 contrast ratio of the color filter can be measured using various RGB color resists.
Dependence of contrast ratio on Pockel's cell crystal surface position
(a) Two horizontal sine-wave gratings with equal and opposite phase-shifts of 22.5[degrees] (relative to the center of the screen) were dichoptically presented to observers through polarized glasses; the perceived phase of the cyclopean percept was measured as a function of the interocular contrast ratio; we derived a balance point when the perceive phase was 0[degrees], which represents the interocular contrast ratio at which the contributions of each eye are equal.
Boasting 33mn subA[degrees]pixA[degrees] els, the advanced display produces an infinite contrast ratio and lifelike perfect colours that are virtually indiscernible from those found in nature.
The 20' diagonal HP W2071d and 23" diagonal HP W2371d LED Backlit LCD monitors offer 1,600 x 900 and 1,920 x 1,080 resolution, respectively, 3m-to-1 and 8m-to-1 dynamic contrast ratios, respectively, and a 5ms on/off response time.
Packed with features like Super fast 2 millisecond response time, Mega Contrast Ratio and easy-to-use controls, this light weight piano-finish body makes it a premium monitor line for customers.
PLC-XK3010 has XGA resolution, a 2,000:1 contrast ratio and 3,000 Lumens brightness
The result is panels that offer a device-level contrast ratio of 100,000:1 or higher.
The screens feature a 12M:1 dynamic contrast ratio and have a 16:9 aspect ratio.
Hitachi's new 3LCD projector has a brightness of 3,000 lumens with a contrast ratio of 2,000:1.
In addition, excellent contrast levels deliver an 80,000:1 dynamic contrast ratio and a Perfect Natural Motion ensures moving objects glide naturally on-screen, eliminating the judder associated with other LCD TVs.
Its 1000:1 contrast ratio and fast 5ms response time help prevent smearing when using the display for fast motion video, while its high brightness (300 cd/[m.sup.2]) provides excellent performance while viewing motion video at high luminance.