Display screen image luminances that are supposed to be the same at different locations on the screen should appear the same.
Additional Information: In normal ambient illumination, for an intended uniform display luminance, the luminance nonuniformity, either stepwise or smooth, should not exceed the threshold for reduced visual performance. Luminance nonuniformity, the variation from the center to the edge of the display, should be a maximum 50 percent of the center luminance. Unintended luminance variations, within half a degree of arc, calculated from the design viewing distance anywhere on the display, should be a maximum of
50 percent. These measurements should be made in a dark room. See IDMS (2012) for measurement information.11 5908, 0700, 9241-303
© ISO. This material is excerpted from ISO 9241-303: 2011 with permission of ANSI on behalf of ISO. All rights reserved.