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公眾號後臺回覆：少兒科普紀錄片
第三季
了解身邊的知識！
BBC 出品
There are lots of
things all around us
Exciting things that surround us
But how does it work?
Do you know?
How is it made?
Do you know?
Things that go up
Things that go down
Things that go pop
Things that go round
With special cameras
to show you inside
It's going to be a big surprise
But how does it work?
Do you know?
How is it made?
Do you know?
Do you know?
Let's find out!
Hello, I'm Maddie,
and today, I'm
out and about taking photographs.
How about the bark on this tree?
Cameras are really useful because
they make pictures
of things all around us.
And my special cameras can do
really clever things.
This one lets us see
things in slow motion.
This one lets us see
really small things.
And I can squeeze this one
into tight places
that are difficult to see.
Hello!
But do you know how a camera works?
Let's find out.
To find out how a camera works,
I've come to a photography studio.
This is the set, and here is where
the person who's having their photo
taken will stand or sit.
This part of the camera
is called the lens,
and it's where light can
get into the camera
through the glass at the front.
And then this dial here...
..controls something called
the iris.
This changes the amount of light
allowed into the camera.
Then the bit that we look through to
take the picture is here.
It's called the viewfinder, but
sometimes we can see the picture
we want to take on the screen
that's on the back of the camera.
When we're ready to take a photo,
we press this button.
It's called the shutter release.
To show you how all these
parts work together,
I'm going to use...
..this cardboard box.
Can you see the hole?
It's called a pinhole,
and it's going to be our lens
to let light in.
And at the back, I've stuck a
sheet of tracing paper.
This is where our camera
will reveal the picture.
Let me show you how it works.
I've got
two colourful lights here -
a green flashing light
on the left
and an orange
flashing light on the right.
And they're both pointing
at my camera.
The bright light will pass
through this tiny lens hole,
travel through the box to the
tracing paper at the back,
where a picture will be revealed.
Wow!
We can see the flashing
lights on the tracing paper,
but something looks different.
Look. Can you see at the top
of the screen - the green light
is on the left and the orange
light is on the right?
But at the back of the
pinhole camera...
..now the green light
is on the right
and the orange light is on the left.
To find out how cameras work to turn
the picture the right way round,
I think we should take
a closer look.
When we point a camera
to take a picture,
rays of light go into the lens.
Light travels in a straight line.
When they go into the camera,
the rays of light swap sides.
Light rays from the top go to the
bottom and the bottom ones
go to the top, left to right
and right to left.
This makes the image turn upside
down and back to front.
To make sure there is enough
light coming in,
the photographer can open the
iris to let more light in
and close it if it's too bright.
They can also turn the
lens to focus,
which makes the picture
nice and clear.
When the shutter release
button is pressed,
a mirror lifts up really quickly.
The upside-down picture
hits the mirror,
which reflects the light upwards.
So, when we see the picture
in the viewfinder,
it's the right way up.
The picture is saved
on an electronic chip,
so that we can keep the picture,
share it and print it out.
Wasn't that amazing?
Shall we take a look at some
cameras in action for ourselves?
Cameras on your phones and cameras
like this one are automatic.
That means all you have to do
is press a button.
But I'm going to show you a digital
SLR camera,
and to see how it works,
I have to take the lens off.
But you should never look inside
or play with a camera
without a grown-up.
If you look inside the camera,
you can see the mirror that reflects
the picture to the viewfinder, so I
can see that everything looks OK.
I'm going to take some pictures
of my two friends Teddy and Bunny.
There we are.
Oh! That doesn't look quite
right, does it?
The shot is far too bright,
so I need to change the iris.
If I turn this, less light
goes into the camera.
But the picture still doesn't
look right, does it?
The picture is still
a little bit blurry.
We say that it's out of focus.
So, if I turn this
part of the lens...
..now the picture is nice
and crisp - it's IN focus.
Which means we're ready
to take a photo.
Teddy, Bunny, say, "Cheese!"
CLICK!
As I pressed the shutter release,
the mirror inside the camera lifted.
Did you hear it?
Let's listen again.
CLICK!
The mirror lifts, and that means
that light can hit the processor
at the back of the camera,
so it can save the picture
and we can see it.
CLICK!
Perfect.
I loved finding
out how a camera works.
What was your favourite bit?
Do you remember the name of the part
of the camera that
controls how much light goes in?
That's right, it's called the iris.
Do you remember the sound of the
camera when it took a picture?
CLICK!
And did you see how the green and
orange lights swapped sides
after they went inside
my special camera?
I think it's time
to have my photo taken,
but I need to get ready.
First, I need to give
my hair a brush.
There are lots of different types of
brushes for different types of hair
and they come in all sorts
of shapes and sizes.
Hairbrushes are really useful
because they help us keep
our hair tidy and healthy.
But do you know how
a hair brush is made?
Let's find out.
To find out how hair brushes are
made, I've come here,
to a hair brush factory!
This factory makes
thousands of brushes.
They've got brushes with handles,
brushes with no handles,
and even brushes with bristles
that go all the way round.
This factory makes hair brush
handles out of wood,
but these blocks of wood are far
too big to become hair brushes.
So, they're cut down
with a rotary saw.
WHIRRING
A rotary saw rotates - that
means it spins round and round.
And this saw is very noisy!
WHIRRING
It sounds like it's whining!
But how does this block
of wood with sharp edges
become a smooth rounded hair brush?
Well, it has to go through
this machine.
It's called a lathe.
Inside this incredible machine,
the blocks of wood are held in
place, spun and flipped around
as spinning parts carve them
into the right shape.
But it's quite tricky to see
what's happening,
so I'm going to use
my special cameras.
And I've been given special
permission...
..to put them on the lathe
so we can see things close up.
First, a big blade spins really fast
and cuts one side of the wood
into the right shape.
It's starting to look like a
hair brush handle already.
Then, another smaller
drill makes a hole.
Next, a circular blade
rounds the edges
so the hair brush feels
nice when you hold it...
..before the machine turns
the brush over
to do the same on the other side.
Isn't that amazing?
One machine turned the wood
from this to this!
So the finished hair brush can be
used over and over again,
the wooden handle needs a protective
coat, but to see this...
..I need a protective coat, too!
It's Peter's job to spray the
handles with a special type of paint
called lacquer, and this will
protect the wood. Here goes.
When the lacquer of goes on,
it's wet like water.
So, the handles are left to dry,
which makes the lacquer go hard.
Now the handle is nice and shiny,
but it doesn't look
like a hair brush yet.
What's missing?
To become a hair brush,
the handle needs bristles.
These bristles are made
from a fibre called nylon,
which is strong and bendy.
Perfect for brushing your hair.
But how do the bristles
get stuck to the brush?
Whoa! This machine
works really fast.
This is the drilling
and filling machine,
and its job is to drill holes
and fill them with bristles.
And it is happening so quickly!
I think we should take a look
with my special camera.
This camera films in slow motion,
which means we can film
things that happen quickly
and watch them back
much more slowly.
When we slow things right down, we
can see all the little bits of wood,
the sawdust, flying all over
the place like little fireworks.
FIREWORKS CRACKLE AND POP
The machine works so quickly,
it can drill nearly holes
in neat little rows
in just seconds.
The little bunches of bristles
are being pushed into
the tiny holes.
But, look, the bristles aren't
all the same length.
So, our hair brush needs to
go for a haircut.
BUZZING
That is the sound of a sharp
edge trimming the bristle
so everything is neat and tidy.
Ready to brush someone's hair.
I loved seeing how a
hair brush is made!
What was your favourite bit?
Do you remember the name of the
man-made material that
the bristles were made from?
That's right, it's nylon.
Do you remember the sound
of the rotary saw
cutting the big piece of wood?
WHIRRING
And did you see the drill
as it made nearly holes
in the top of the hair brush?
It's my turn to have
my photograph taken now.
So, the next time you're getting
ready to have a photograph taken,
you'll know how a hair brush is made
and how the camera works
that's taking your picture.
I think this one is my favourite.
I'll see you next time.
There are lots of
things all around us
Exciting things that surround us
But how does it work?
Do you know?
How is it made?
Do you know?
Do you know?Let's find out!