[pedrocr]

What that whitepaper is saying is that "if you only sample 2xMaxFreq and then connect the dots with straight lines it doesn't really look like a sine wave so buy 5x as much instrument from us". That's a total cheat as that sawtooth graph they show is only possible if you allow higher frequencies. If the signal is bandwidth limited at the frequency of the sinewave the points you sample at 2xFreq only have one possible solution for the graph (the sinewave again). There are some great videos about this recently by xiph's monty:

https://www.xiph.org/video/

So if you sample 2xMaxFreq you have samples that describe the full signal and can reconstruct it exactly. So if our eyes really are 100Hz we can't see anything above 50Hz. That seems to align well with the ~50/60Hz threshold for flicker free viewing. Apparently higher framerates are only useful for when we have fast movement across the field of view which would be the case for FPS:

https://en.wikipedia.org/wiki/Flicker_fusion_threshold#Visua...

[hackinthebochs]

I just finished going through a Fourier Transform course. The technical answer is that you don't interpolate the samples with lines, but with the sinc function. The sinc function is sinusoidal and so it more naturally approximates waves. In this case 2xMaxFreq is enough to reproduce it exactly. Using linear interpolation in the whitepaper is a blatant lie.

>So if our eyes really are 100Hz we can't see anything above 50Hz.

I'm not sure this follows as we're not perceiving waveforms when light hits our eyes, but we're perceiving intensity of energy hitting our receptors.