High-speed videography of transparent media using illumination-based multiplexed schlieren.Schlieren photography is widely used for visualizing phenomena within transparent media. 
schlieren photography
To date, high-speed schlieren videography can only be achieved using high-speed cameras, thus limiting the frame rate of such configurations to the capabilities of the camera. 
high-speed cameras
The presented results demonstrate the ability to acquire a series of images of flame structures at frame rates up to 1 Mfps using a standard 50 fps sCMOS camera.
sCMOS camera