> If you watch a video like [0], the squiggles aren't real, they're an artifact of a rolling shutter camera.
...is this correct? You can say this about any oscillating phenomenon - that doesn't mean it's not 'real'. The "squiggles" are an artifact of the frequency of the string and the scan rate of the rolling shutter. You'll also see artifacting from a global shutter camera, where the "squiggles" will be an artifact of the string frequency and the frame (rather than scan) rate.
Or do I misunderstand?
I've been playing guitar for 25 years, and it seems to me that I can look at the "squiggles" from a rolling shutter capture of a string and tell you which string it is (and possibly, if I'm having a particularly sharp day, whether it's E or drop-D). I've never tested myself this way - am I certain to fail? :-)
Every pixel of every frame was really captured by the camera from the source, but it’s being played back to you very differently than how the source actually looked.
The most obvious example of this would be the wagon-wheel effect, where a spoked wheel can appear to rotate at a different speed and direction than its true rotation when captured by a camera under certain conditions.
How could you tell the note by looking at a string? Unless you’re talking by about marking timestamps and measuring the time between peaks. A 42 gauge string tuned to E or D or any other note are going to look basically the same.
GP is talking about seeing the string oscillations alias against the 30 Hz camera frame rate.
I've never tried it.