Search Results for: schlieren

A Simple and Inexpensive Schlieren Optical System Using a Fresnel Lens

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.

Schlieren Photography Lets Us See an Invisible World

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.

See Airflow on Camera in This Awesome Harvard Demonstration of Schlieren Optics

Schlieren flow visualization and photography is one of those things that is just too cool. Using an optical trick, it allows a camera to capture, "small changes in the index of refraction in air." In other words, it can see anything that affects airflow: heat, sound waves, or just plain old air currents themselves.

And the video above, uploaded at the beginning of this year by the Harvard Natural Sciences Lecture Demonstrations YouTube channel, is one of the most fascinating demonstrations of Schlieren optics we've ever seen.

Photograph Sound & Heat Waves with this $9 DIY Schlieren Flow Visualization Setup

Schlieren Flow Visualization is a rather fascinating technique by which you can see and capture the differences in air pressure caused by various forces such as sound or heat.

And if the video we shared recently explaining/showing off this photographic trick had you yearning to try it for yourself, you're in luck, because there's a way you can create your own DIY Schlieren Flow setup for only $9.

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.

Lasers Reveal How Well Different Types of Facemasks Work

With a supply crunch in medical-grade facemasks, the general public has been turning to homemade masks in order to slow the spread of COVID-19. Now researchers are using lasers to reveal how effective different kinds of DIY masks are at blocking tiny droplets from coughs and sneezes.

This Old Photo Technique Shows How Masks Help Prevent the Spread of COVID-19

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.

How to Capture Heat on Camera Without Expensive Optics

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?