News | July 7, 2016

High Speed Cameras: Fast As Lightning

Source: Vision Research, Inc.
High Speed Cameras: Fast As Lightning

As those familiar with the photography industry know, the name "high speed cameras" is a bit ironic when you consider they actually slow things down. Technically, "slow motion cameras" would be a more apt title. Regardless of what you call them, 1000 FPS cameras are an integral part of modern research and scientific studies. One recent fascinating example of just how shocking (and cool!) the results of high speed cameras can be comes from researchers at the Florida Institute of Technology.

According to The Huffington Post, the researchers recently completed a project in which they used a high-speed camera to capture lightning strikes. The occurrence, origin, and phenomenon of lightning is still not entirely understood or agreed upon by the scientific community, and so the researchers from FIT wanted to shed some more light onto the matter by enlisting the help of high speed cameras to witness exactly where and how lightning forms and strikes.

“We know lightning exists, but it seems that the electric field is not large enough for lightning to get initiated,” according to physicist and principal investigator Ningyu Liu, of FIT’s Geospace Physics Laboratory in Melbourne, Florida. “Lightning is an electrical discharge process and we know, to start lightning, we need a very large electric field, which can accelerate free electrons inside the cloud. But so far, from measurements, it seems the electric field inside the thunder clouds is actually not that large. Certainly it doesn’t exceed the threshold value to start electrical breakdown.”

The shutter speeds of high speed cameras helped researchers take some amazing shots of one of nature's mysteries. While regular photography taken in sunlight might work with shutter speeds that are 1/125th of a second, shutter speeds for high-speed photography are as fast as 1/8000th of a second. The shutter speed of a camera is usually measured in fractions of a second and typically ranges from one full second to 1/1000th of a second. The longer the shutter remains open, the more light is allowed onto the film.

Liu and his colleagues were able to capture instances of a phenomenon that challenges our very notion of lightning: strikes that move upward instead of down.

“Sometimes lightning can propagate upward from the thunder cloud tops," Liu explained.

The work done by the FIT researchers is a bit reminiscent of the first-ever practical application of high-speed photography. In 1878, Eadweard Muybridge used it to capture a sequence of a horse galloping, which settled a longstanding debate: whether horses' feet all come off the ground at once during a trot and a gallop. It turns out that they do, and that for a split second during each stride, the horse is actually airborne. Muybridge presented a single photographic negative depicting his own horse, Occident airborne at the trot; unfortunately, the negative no longer exists, although woodcuts depicting the photographic evidence do.


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