What is the difference between an on-screen measurement and a distance measurement?


This article applies to the following products:

There are two documented ways of measuring display luminance:

  • On-screen: The sensor is placed on the display surface. No ambient light influence will be measured. This is the most reliable method for measuring. When performing this measurement, the reflected ambient light will need to be added to all your measurements in order to have an accurate measurement. Find out in the following KB article where you can find the calculated reflected ambient light in QAWeb: [KB7941]
  • Distance: The sensor is held at a distance (typically 50cm). Any ambient light which reflects on the screen will be measured by the sensor as well. Here, the measurement can be heavily influenced by changing ambient light or for instance moving the sensor during the measurement.



Last updated Oct 31 2018

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