The orange colours are from hard surfaces, like plastic and wood, while the yellow colours are from even harder surfaces, like the metallic frets and the microphones. The blue grey colours are from the guitar strap, which is fabric. So the colours show surface textures, with their sound absorption properties.
Sound gets reflected and casts shadows, like light. The cameras objective is one meter across, so it is quite big, which is necessary for making pictures from sound, because sound waves are much larger than light waves. The lens is fish-eye, and the numerical aperture is almost one. I plan on removing distortion from the lens, and use bluer sound, when I get the time.
In use it is somewhat like a macro lens, or a microscope, giving a thin plane of focus. Here is a video of focusing:
The wave field can be seen in this video.
By Kim Øyhus (C) 2013-11-11