If you're looking for a fun and educational project to try this weekend, Israeli DIY-er Elad Orbach has come up with the cheapest, most simple Schlieren photography setup we've ever seen. Unlike more expensive setups, his creation will let you photograph heat and sound waves using just a smartphone, a mirror, and a selfie stick.
Advanced imaging company LaVision has released a new video that shows just how effective a face mask can be at preventing the spread of infections like COVID-19. The video lends visual support to the CDC's recent recommendation that everyone wear a mask in any situation where it is difficult to maintain social distance.
Schlieren imaging is a fairly standard optical technique for visualizing heat, sound, or pressure differences in air. Technically, a schlieren system is able to see clear disturbances in air due to slight differences in the speed of light in the air. The technique can be sensitive enough to see the heat rising off a human hand at room temperature.
Standard schlieren imaging techniques use a large mirror to be able to visualize heat or pressure differences in air. The problem with these techniques is that they require large precision telescope mirrors that are very expensive. My lab is fortunate to have a 13-inch diameter telescope mirror; but what happens when I need to photograph a larger subject?
Have you ever wondered what a gale-force sneeze would look like if you could see air currents, temperature gradients, and differences in pressure and composition of the air? Or, less disgustingly, the strike of a match? This fascinating 6-minute video demonstrates Schlieren photography, which makes the invisible visible.
Capturing the supersonic shockwaves of a fighter jet going faster than the speed of sound might seem like science fiction, but NASA actually captured this phenomenon on camera. Not only that, they did it by using a 150-year-old German photography technique.