An Inexpensive Schlieren Video Technique

The video shows hot air around a soldering iron.

Download Video: MP4: OpturaSchlieren.mp4

"Inexpensive schlieren video technique using sensor dead space as a grid,"
Robert B. Teese and Matthew M. Waters,
Optical Engineering, Volume 43, Issue 11, pp. 2501-2502, November 2004.

Matt Waters published a short book about the method.

Links for more information about schlieren photography: