How to Photograph Heat Waves Using a Phone, a Selfie Stick, and a Mirror

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.

For those of you who haven’t read some of our previous coverage of Schlieren photography, this technique typically uses a special lens or a curved mirror combined with a knife edge to distort the incoming light just enough so that you can literally visualize sound and heat waves. The technique is often used in aerodynamic testing, but it’s a favorite of homebrew photography hackers as well.

We’ve featured a few more advanced setups in the past, and even some affordable DIY versions, but Orbach’s creation is definitely the simplest we’ve ever seen. All you need to replicate his results is a smartphone, a selfie stick, and a parabolic mirror. The phone is mounted on the handle-end of the selfie stick, the mirror is glued to other, and a light source is placed near the mirror.

Using a selfie stick allows you to “dial in” the correct distance between your phone’s camera lens and the parabolic mirror using an LED point source. Once that’s all set, you have the perfect “Schlieren on a Stick” setup to play with!

You can see the setup in action in the videos below:

For a detailed step-by-step breakdown explaining how to build this yourself—including a few behind-the-scenes photos—head over to Elan’s blog. He also mentions a couple of helpful hints for those of you who want to give this a shot, namely: find a very rigid selfie stick, and pick a video app that allows you to turn off auto-exposure, or else you’ll find yourself constantly re-focusing.

(via Hackaday)