Sound Camera v.2
Imaging with sound instead of light.

I invented and made this camera, which focuses sound into images, instead of light. It is a sound wave field camera. It was difficult to make, and took many months of hard work, but it seems to be the highest resolution acoustic camera on the net.

The colours are real, as represented by different pitches of sound, in the same way the human eye sees colours, which are different frequencies of light.

Sound waves from loudspeaker

These are real sound waves, made up of travelling pressure differences in air. The tweeter makes the sharp rings at the top, while the woofer makes the blobbish pressures below.

Loudspeaker by reflected sound

Loudspeaker by emitted sound

The tweeter at the top looks similar to what it looks like in light. The dot in its middle is the dome.

The woofer at the bottom however is shimmering or something. Its membrane do strange things with sound.

The tweeter dome looks like a light bulb, shining on its base with a little lens flare and putting the woofer in shadows.

The grey bluish mist in the woofer is there because of the audio crossover filter, which lets a little sound through. It is bluish because it passes higher frequencies more.

Electric guitar

Clothes hanger

Keyboards

Potted plant

My fender telecaster. It is my favourite object for testing my sound cameras, and therefore the first one imaged. It is a hard object, so it is quite shiny when looked upon with sound.

The yellow green stripes are standing soundwaves. I removed those for later pictures.

The clothes hanger is shiny in sound, while clothes are not.

Thin membraneous things often behave strangely when seen in sound. They can become transparent, or shimmering, like oil on water.

This imaging is by hearable sound, not by ultrasound, so the smallest features which can be discerned are about the size of a key. The keys can be clearly distinguished on the first keyboard, but not on the second one, which is slightly smaller. Leaves are fairly transparent in sound.

The white blob at the bottom is a reflection in the pot.

Specifications.

Objective diameter: 50cm.
The objectives imaging properties are very good, and remaining distortions are due to noise, uneven "illumination" by sound, and physics.

In use it is somewhat like a macro lens, or a microscope, giving a thin plane of focus.

By Kim Øyhus (C) 2014-7-7

kim.oyhus@gmail.com