Notice that they are similar to other cases of surfaces (in the simulation and videos above) but because of the shape of the guitar and irregular thickness of the surface, the nodal patterns are not e...Notice that they are similar to other cases of surfaces (in the simulation and videos above) but because of the shape of the guitar and irregular thickness of the surface, the nodal patterns are not exactly symmetric. If the reflected beam comes off a surface that has moved half a wavelength (at the instance the camera shutter opens) the two beams will be out of phase and not expose the film.
