Technological innovations over the last decade resulted in significant improvements in the LCD's viewing angle performance. Consequently, the current method to define the viewing cone, with a fixed contrast ratio, does not represent perceived performance differences between displays. Our previous study, with two LCDs and a plasma display, revealed that changes in image quality with viewing angle are predicted by combining luminance variations and white-point shifts for an intermediate grey level. In this paper, we show that, for viewers comparing the viewing angle dependent quality between displays, that same relation holds. If the calculated viewing angle is larger than the measured acceptability threshold, the remaining quality at the threshold angle serves as a viewing angle performance indicator. © 2008 Elsevier B.V. All rights reserved.