Smearing

Smearing is an effect which appears if the form of 'tails' at motion pictures. This effect arises mostly at passive LCDs (STN, DSTN) because of the low action of the Liquid Crystals. When using fast motion pictures with high differences in contrast, it is possible the Liquid Crystals cannot accept the new condition in a sufficient quickly manner. Similar effects can only be noticed  at a low rate in TFT-Displays and CRT-Monitors (CRTs are always
searching a compromise for the phosphors used, i. e. between the fast time of reaction and the suppression of
flicker by sufficient persistence of the phosphors. The test patterns represent an extreme situation for a display, a fast motion picture with high contrast on a black background. First the display has to make a fast change from 0% contrast to 100% contrast, and in the following from 100% contrast to 0% contrast.