The first line of the articles says "seven-millionths of a second", which would be 1/7μs or 0,14μs. They also mention that the camera shot 16 frames in that period, so that would be once every 0,00875μs or once every 8,75ns
Youtubers are a couple of magnitudes away from that, AFAIK
I would say you described "one seven millionth" of a second (1/7,000,000 s)
"Seven millionths" would be 7/1,000,000 s (7μs). They take 20 to 40 images in that period using 7 cameras, so any given camera might be as low as 1.4μs per frame.
Yes, but they said seven-millionths of a second, not seven millionths of a second. Technically they're right that that's what it means, but I'd expect an editor to recommend against that phrasing in favor of the one you used to avoid confusion.
Well, it's true that the article says "seven-millionths".
I would guess it's a lot more likely that this is an editing failure, introducing a hyphen where no hyphen should be, than that they meant to divide a second into seven million equal parts.
For one thing, as SECProto alludes to, English would normally require you to say "less than a seven-millionth of a second" if that was what you meant. There's no such thing as saying "less than weeks". You have to specify less than how many weeks.
The slow mo guys did a video [1] at 10 trillion FPS. They also recently did another video [2] at 5,000,000 FPS. Their other videos vary between 50,000 FPS and 850,000 FPS.
Edit: They mention in [2] that the Phantom camera they have can go to a 95ns exposure up to 1,750,000 FPS.
The 10 trillion FPS number comes from the fact that they’re taking advantage of a strobing effect in the light they’re filming, such that if the strobe is happening at (for example) 1000Hz, they can get a frame at time T, then a frame at time T + 1.00000000001ms, then T + 2.00000000002ms, and so on. Then you stitch it together and it looks like they’re a 10-trillionth of a second apart.
No camera is taking in 10 trillion frames of data per second.
I've never heard of `{number} {plural magnitude}` meaning `mag / number`. I've only ever seen it mean `number * mag`. As in 3-thousandths == 3 * 0.001 not 0.001 / 3.
Youtubers are a couple of magnitudes away from that, AFAIK