Alexey Blinov wrote: > I measured color on different places on a fully white screen. When visualized > on the CIE 1931 > x,y plane, I got an area of size around 0.01. The distance between two > closest shades of white > (255,255,255 and 254,255,255) is around 8e-4. Accuracy of the colorimeter, > i.e. the diameter of > the smallest circle enclosing many measurements of same color at same place, > is around 4e-4. > > So, variations of color on the screen is around 10 times more than the > variation due to limited > (8-bit per channel) digital representation. Who measured such unevenness of > professional > monitors, could you post your results? Hi, spatial color unevenness in screens is a quite well known display defect. One of the specifications of higher quality screens is improved spatial screen uniformity, and many of these displays take technical measures to ensure uniformity, such as spatial calibration systems. (I'm not sure x,y values are a good way of evaluating non-uniformity, since they do not correlate to visual differences. Delta E is a better measure in this regard.) There are various industry standard methods and thresholds for display uniformity measurement, such as VESA and ISO standards. Graeme Gill.