I'm wondering if any of you have heard of schlieren photography? I've been following it for a few years now, and would love to investigate the possibility of making a portable unit for use in paranormal investigation.

Just a bit of background for those who are not aware of what it is. Its a way of photographing or filming the tiny disturbances in the air. Even the tiny air turbulence caused by moving your hand shows up as a Hurricane-like wind storm within such a photograph.

The theory is that if there is some form of entity, it may be visible in terms of air disturbances or currents.

Anyone played with this, or looked into this?

Here is an article which explains what itis.

Schlieren Photography - How Does It Work?