Brightness, Contrast, Uniformity, And Gamma
Out of the box, Lenovo’s 27” touchscreen offers a native white point of 7900 K. Both the color temperature and contrast ratio of the screen also remain consistent across most brightness levels. A white point of 6500 K is considered neutral and close to the color of midday sun. If a screen measures below 6500 K, it takes on a warmer appearance that leans towards reds and oranges. If a screen measures above 6500 K, it is said to have a cooler appearance that favors the color blue. Cooler color temperatures are common in a retail environment because they make screens stand out next to other displays.
The IdeaCentre Horizon display produces moderately good brightness uniformity with a maximum deviation of 10%. Maximum brightness is less impressive at 225 cd/m2.
Color uniformity is even less impressive than maximum brightness, with a Delta E of 5.0 between alternate corners. Many people consider a Delta E of 1 to be a noticeable variation, depending on the color.
The IdeaCentre Horizon’s measured gamma response is very close to the standard 2.2 curve used by most Windows systems. A gamma response curve corrects for how the human eye is able to see light and dark colors, and large gamma errors may cause issues with editing or viewing photos. There are no gamma issues present here.