Measuring PWM Flicker

Overview

This doc describes how I test for PWM flicker in a display. To learn more about what PWM flicker is go here: PWM flicker.

Process for measuring

  • Get a smartphone

  • Set the photo mode to "pro"

  • Set shutter speed to the fastest possible. For example 1/12000s

  • Point the smartphone camera at a display to test for PWM flicker

  • Set the display brightness to the lowest setting (0%)

  • Now steadily increase the display brightness from 0% to max brightness (100%) and look at the phone's camera preview

  • If there is PWM flicker

    • you will see it as horizontal black bars that move up and down the display

    • The black bars will be thicker when the brightness is lower

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