Name: How do 3D glasses work - Sixty Symbols
Uploaded: 2020-03-30T05:25:34.000Z
Duration: 10 min 26 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Adverbs of degree

but these are really amazing it I'm gonna do something that I've never done before.

I'm gonna invite you Brady to come to the toilet with me.

Do so we're gonna talk about three D movies.

And how do three D movies and three D glasses work?

What's the technology behind these things?

I want to see Hugo, which is a wonderful, wonderful film before Christmas with my daughters.

Well, it's based around what the first question go ask is, Well, why do we have depth perception?

We get some sense off Brady so far away from me?

I can sort of see that he's a solid object rather than a plan.

The key thing is, we've got a physical to ace, and they're separated by a certain distance.

So both of these I see a slightly different scene on your brain is unbelievably clever, taking those different scenes on bringing them together and giving you that depth perception.

So the question then is how do you get something that's flat on a screen in a cinema or on a television and give you that depth perception.

Well again, What you need to do is to have those.

You're playing different scenes to different eyes.

But what you do is you have two cameras when you're filming the movie.

One camera is filming workers to the left.

I want cameras filming what goes to the right.

Andi, You bring those together and you have a slight offset.

Which is why when you take your glasses off, everything looks quite blurred on the screen.

So the challenge that the cinema is well, how do you take something on a flat screen?

And how do you deliver those two separate scenes each toe?

One I How did you get the dirty trick the brain into thinking that scene is not really depth on dhe.

Remember, some of the slightly older viewers might remember that you used to have red and blue glasses.

You have these 10 2 things, and in the eighties I think it tickles all the way back to maybe the forties.

I could be wrong there, but I think that that sort of red and blue approach hards being around a long time.

What they do is they basically have red and blue filters.

They take the the film that one cameras shot on the Take, a film that the other cameras shot, one of which has a blue 10 theater, which is a red tint on.

Then they use blue and red filters to separate those out.

So the one that's got the red tent will come to the the red eye as it were, the ones with the blue team record of the Blue I Yeah, we've moved on, and the problem with red and blue offices that you're playing with the colors you're losing color definition.

The depth perception isn't as good, actually, with the colors on dhe.

It's very problematic in terms off getting a nice high definition movie.

Well, actually, what we do is we play with something called the Polarization of Light.

You've come across Polaroid before, and Polaroid is basically a thin film.

I've got some of it here and in that thin film are lots and lots off polymer molecule, long chain molecules that are stretched in a particular direction.

You take a piece of off Polaroid film, you match them up like that, you can roughly see tribute, I guess.

And then when you turn it together, turn it, turn it round 3 90 degrees.

I'm afraid to Undergraduate physics A level physics, high school physics.

This is gonna be tricky to explain at, ah, non scientific level.

But lights or wave, let's start without all the times that behaves like particles.

For the purposes of this, we're gonna take that lighters with so light is a wave.

Well, it's what it is is electromagnetic wave.

It's an electric field on a magnetic field.

We're gonna concentrate here only in the electric field, cause that's all really that matters.

So this thing lights propagating like that in that direction.

Now it's got we call it an electric field ve actor on what that basically is, is tells us which direction the electric fields pointing.

So in this case, it's propagating that when the electric fields pointing that where we turn it around like that, it's propagating now when the electric fields pointing that way turn around like that, the electric fields pointed that way.

Of course, this is going back and forth gazillions of times a second.

That's only really need to know you've got this this characteristic off the wave, which tells you basically in which planets vibrating.

So what the Polaroid does is when you've got, you know, the lights, you got all that that that the light that's in this room and that light is basically own polarized, right?

That means that that that it's it's got some light waves which are like that so much I like that so much.

All right, friends of different organizations.

So all the lightness one wasn't, uh or random, but it was actually going in one direction.

Then what you have is, if you're lying, you're Polaroid in the direction off the east off the electric field.

Um, Then what you find is that they're like and get through very simply.

However, if you rotate it round just like I did with the Polaroid before them, it doesn't get through.

And that's a very, very useful property of light of certain materials like Polaroid.

What happens is that you use these glasses.

So in one side, the simplest version of these is that on one side we have a Polaroid, basically, which is a line like this on the other side with a polarizer Polaroid film which is aligned like this.

So what happens is that you take those two, uh, different versions off the movie which are filled with different cameras, and you polarize.

You put a polarizer in for each one of those cameras as it where, and that means that the light coming from the screen associated with the left I see is polarized this way on the late coming from the screen associate with right, a is polarized this way.

You've got a way of differentiating distinguishing between what should be going to the left eight on what should be going to the right.

You're watching two moves and once with slightly different scenes, and then you are using the polarization of the light coming from the screen.

T trick your brain into thinking Well, okay, What I'm seeing here is real life, and therefore it must have a depth.

It isn't really linear polarization here.

What we actually have with these glasses and many of these glasses is something called circular polarization.

There, instead of this electric field being in the plan like this, it rotate around.

So it's rotating like this or in the other direction.