To visually illustrate the risk of airborne transmission in real time, The Washington Post used a military-grade infrared camera capable of detecting exhaled breath. Numerous experts — epidemiologists, virologists and engineers — supported the notion of using exhalation as a conservative proxy to show potential transmission risk in various settings.

“The images are very, very telling,” said Rajat Mittal, a professor of mechanical engineering in Johns Hopkins University’s medical and engineering schools and an expert on virus transmission. “Getting two people and actually visualizing what’s happening between them, that’s very invaluable.”…

According to experts, the footage underrepresents the potential risk of exposure from airborne particles. Those particles may spread farther or linger longer than the visible exhalation plume, which dissipates quickly to a level of concentration the camera can no longer detect.