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  • Hey, Vsauce. Michael here, and I just got back from

  • VidCon. The entire convention was incredible, but the whole time I was

  • there

  • I thought a lot about video. We all watch video

  • and many of us work with video, but what is it? I mean, what really

  • is video? Well, guess what, today we're gonna take a look.

  • To begin I think we should start all the way down at the bottom

  • with language. What does the word record mean?

  • The story behind the word 'record' is actually quite cool and makes me a little

  • sentimental.

  • The word 'record' comes from the Latin, where "re" means

  • again and "cor" means the heart or the soul.

  • So when you record something you are literally bringing it back

  • into your heart, bringing it back into your soul, remembering it.

  • Now, that sounds really nice and pretty, but it actually had more to do with the

  • fact that

  • ancient people thought that the heart was we were stored memories, not the brain.

  • The reason a sequence of still images can appear to be moving

  • is an effect known as "beta movement." If images move fast enough

  • our brain can't comprehend them as separate images and the illusion of

  • motion

  • is created. Now, for a very long time we recorded

  • moving images on photographic film, but later on

  • a new way of capturing moving images came about and it was called

  • "video." Video comes from the Latin for "I see"

  • and rather than preserving a moving image chemically on celluloid

  • photographic film stock, video is an electronic

  • representation of the moving image. Now in the real world stuff just

  • happens. The things just continuously happen. But in the world of a camera,

  • whether it's film

  • or video camera, it's almost always in the form of frame rates.

  • Pictures of the world taken at a certain speed that are then quickly gone

  • through

  • producing, through beta movement, the illusion of movement.

  • When a camera records at a lower frame rate, playback often looks

  • jittery and skips like this. More frames per second means that more information

  • is taken every second

  • leading to more fluidity. But that leads to a whole can of worms,

  • which is a great transition to a conversation I had with Dylan from

  • HouseholdHacker at VidCon.

  • Roll the tape.

  • Hey, Vsauce. Michael here, and I am in the bathroom at VidCon and I've got a special guest. Right outside

  • it's Dylan from HouseholdHacker. Hey, what's going on everyone?

  • You know, I got a good question for you based on frame rates and what not. What would you

  • say

  • the human eye sees as a frame rate? Very good question. What frame rate do we see the world in with our

  • eyeballs? I mean,

  • how fast does information travel from our eye to our brain?

  • It obviously can't be too low, because fast objects don't look like they're

  • skipping,

  • they look pretty fluid. Well, it's a little bit of a trick question because our eyes

  • are not cameras. Instead, they track onto objects

  • and receive a continuous flow of photons onto the retina

  • sending information via a chemical reaction

  • to the brain. Now, here's what we do now. The visual cortex in our brain

  • usually holds that information from our retina for about a fifteenth

  • of a second. So if an animation moves fifteen frames a second

  • or faster, it's gonna look nice and fluid. But

  • if it's lower than fifteen frames a second, our brain's not fooled by the beta

  • movement

  • and it'll look like it's skipping. So, basically, the faster the frame rate, the better

  • everything's gonna look in the end. Here's the thing. If frame rates get higher and higher,

  • you wind up with an image that can actually cause headaches when people

  • watch it on the screen.

  • Uhm... Here, I'll explain why. Hold this camera for a second.

  • Oh yeah, no problem. So back to the point

  • about our eyes tracking onto objects. If I do this -

  • move my hand in front of my face and track it with my eyes -

  • I can see my hand, it makes sense. But at a certain point my hand will move so fast

  • that it's just a blur and the reason it's a blur is because my eye

  • can only track so fast. And when objects move faster than our eyeballs can track, your brain

  • adds in

  • motion blur. That way we get a sense of movement happening,

  • but we don't see something like a hand randomly

  • appearing all over the place. But this becomes a problem with new

  • high-definition programs on

  • big televisions, because some of those programs are brought to your TV

  • at frame rates as high as a 1000 frames a second.

  • And objects, like a tennis ball, that normally travels so fast

  • our eyes can't track them and they look blurry don't look blurry,

  • because the camera is able to see them clearly. And when you watch that program

  • on TV

  • you can actually get a headache or get dizzy, so they're having to find ways to

  • add blur

  • back into HD pictures. Pretty neat, right?

  • That's great information. How did you learn this? That's what I'm here for, man.

  • Thank you. See you. See you.

  • You know, the bathroom. You know. I heard you coming out. Did you wash your hands?

  • Uhm, yeah.

  • So there you go. Some cool facts about video that I learned while I was flying

  • to

  • and from VidCon from New York to LA. It was a long flight, but I learned a lot

  • and I wanna end with some numbers about YouTube specifically.

  • YouTube host videos from all over the world. Massive,

  • massive amounts. In fact, every minute of the day

  • people are uploading video to YouTube. And if you were to take all the video

  • uploaded to YouTube at any given minute, all together it would equal

  • 48 hours. That's right. Two full days of video

  • are uploaded to YouTube every single minute. You guys are part of something

  • gigantic. All right, now later this week I'll have a new episode of IMG.

  • And soon enough we'll have episodes of DONG, LÜt, it's gonna be super cool, so be

  • sure you're subscribed so you don't miss anything.

  • And as always,

  • thanks for watching.

  • They're not, they're not the same person.

Hey, Vsauce. Michael here, and I just got back from

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B1 中級

ビデオとは何ですか? (What Is Video ??)

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    林宜悉 に公開 2021 年 01 月 14 日
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