photon78s How do you define "reasonably low flicker" in your oscilloscope measurements? I have been using 20dB gain on the detector but have tried higher gain settings but that makes it even harder to find a device with a "flat" waveform.
Before I answer that, let me refer to this chart. I pulled these numbers from the Thorlabs site:
10dB = 3.3x
20dB = 10x
30dB = 33x
40dB = 100x
Here's my favorite (now dead...) laptop. Barely any flicker at 40dB/100x magnification:
![](https://i.imgur.com/unDNuSj.png)
Here's the same model, but with a different panel. This is unusable for me. I assume the flicker is what makes it unusable, but I can't say that for 100% certainty - maybe something else that can't be picked up by the photodetector (like FRC or pixel inversion) is causing the problem.
![](https://i.imgur.com/xNYfGzL.png)
Here's the LG 27MQ450-B at 100x magnification:
![](https://i.imgur.com/JGKFO2H.png)
I have the waveforms for all the monitors in the table a few posts above in case you want me to post a few of the waveforms. I'm too lazy to post all 20 of them though. :-)
If you want more details, you might be interested in this thread:
https://ledstrain.org/d/2598-help-wanted-to-measure-flicker-andor-test-a-flicker-free-monitor