[tngranados]

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

[SECProto]

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.

[alberth]

Saying ~140k photos per second would have been a more understanding stat if only the article framed it that way.

[thfuran]

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.

[thaumasiotes]

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.

    less than (seven) (millionths of a second)

ordinary grammar, ordinary unit choice

    less than (seven millionths of a second)

improper grammar, bizarre unit choice.

[thfuran]

I agree based on the whole sentence in the article that that was probably an editing error.

[rhdunn]

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.

[1] https://www.youtube.com/watch?v=7Ys_yKGNFRQ&pp=ygUMc2xvdyBtb...

[2] https://www.youtube.com/watch?v=BTkZ36g4GOs

[ninkendo]

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.

[kazinator]

"electron beam that can be broken down into customized pulses" also sounds superficially like strobing.

[ted_dunning]

Not with X-rays they aren't.

[montag]

I understood the article just fine, despite the spurious hyphen. The HN title could be improved immensely if it just said 7 microseconds.

[dbeardsl]

I think this is incorrect reading of the numbers

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.

7 * 0.001ms = 0.007ms or 7us or 7000ns.