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Vibrating surfacess when recording with high speed cameras using certain patterns is an interesting observation. Let me take a stab at explaining what might be going on in kinda layman's terms.

So from what I understand, you're recording either sinusoidal or binary patterns on something using a FASTCAM Mini, right? And with the sinusoidal patterns specifically, the surface in the footage seems to be vibrating or moving in a weird way. But it doesn't do that for the binary patterns.

My best guess is it has something to do with how those different patterns are constructed wavelength-wise, if that makes sense. Sinusoidal patterns are basically a continuous sine wave - so they vary smoothly and gradually through shades of gray as it cycles through bright and dark.

Compared to a simple on-off binary pattern, where there's just two distinct brightness levels switching between each other very abruptly. The transition between values isn't as smooth.

Capturing super high speeds like your FASTCAM can, even tiny fluctuations in brightness or shading could end up looking amplified and like motion on the surface. But binary jumps between levels so fast and starkly that it may not have the same "blurring" effect, if you follow me.

Kinda like how a movie at 24fps can look smooth to our eyes normally, but speed it up insanely and suddenly it looks jittery as hell! Let me know if any part of that is unclear or if you have any other thoughts on why it might be happening!