Matt Rece
1 HN recommender · recommended in 5 months, 2009–2023
10:00 · 16M views · Sep 29, 2009
Ten minutes of ultra-slow-motion footage of bullet impacts filmed at about one million frames per second by Werner Mehl of Kurzzeit. It includes hollow points in ballistics gel and impacts on glass.
Used as the go-to example of genuine one-million-fps footage and of bullet impact physics.
5 comments from Hacker News
Youtube video: direct link... this video The watermarked website is a wreck. More than just bullet impacts. At around 2:00 I think it is showing a BB sized object hitting a bullet from a perpendicular trajectory. At around 3:00 there is some nice bullet into bulletproof glass action. 5:50 has shockwave formation in liquids. Back of envelope calculations suggest that most of this is at less than 1,000,000 frames per second, but the slowest of the slow might be at a million.
True, but if you can do 1m fps on earth[1] and the MRO travels at a speed of 133,879.68 inches/second then you could take 7.4693934 pictures per inch even if you had a rolling "scanning" shutter. I know that would be way to much data for them to process, but for the 172 seconds from parachute deployment to touchdown you could have one amazing high speed film. I am sure NASA can fund a high speed camera for MRO... or do we need to crowdfund that one as well... [1] this video
The egg splattering on to the keyboard would not happen because there is not enough kinetic energy in that small bullet to make it splash back very far, the lightbulb though for sure put some fragments in to his keyboard because the shards bounce off each other and will cause some shards to go in the opposite direction of where the bullet came from. See here for some more 'bullet impact' video: this video
It sounds like they are taking different phases of the light spreading, and it just looks like the light is traveling. While cool, it's not a true 1 trillion fps camera. Here's true 1 million fps footage: this video
Also, depending on how the bullets get caught at the range (shredded tires vs sand vs steel backstops), they tend to produce a lots of fine lead dust[1]. [1] - this video