degen Might have mentioned this elsewhere, but someone investigating the "variable refresh rate" with the display of the Pixel 6 Pro used a Radex Lupen flicker meter but used an FFT chart, which is a plot of amplitude over frequency (frequency spectrum), whereas the traditional oscilloscope measurements are voltage over time (frequency).
You can see how individual frequencies have a higher amplitude so it is measuring more than a single frequency.
On a sidenote. I vaguely recall the laptop Intel sent to the "lab" with alleged differences in visual quality between two driver versions used some hardware that might have conducted a similar measurement and that was inconclusive so it might not catch all the "boogeyman" that we're interested in, but I think it would be a mistake to ignore this.
