What’s up? I’m Destin.
This is smarter every day get your phone now.
You see that little camera assembly there.
Let’s take it out of the phone.
Yep, that’s what it looks like.
So here’s what we’re going to do.
The first thing we’re going to do is pop the lens off,
and there we go, that is called a CMOS sensor
that is the camera on yourphone.
So when you take a photo or a video with your phone,
you will think that it exposed that entire chip at one time
like snapping a photo.
That’s not heavy works.
It actually scans down the chip and
that’s how images are created.
This is called rolling shutter
and it’s the exact reason your cell phone
makes wired shapes out of fast-moving objects.
This is a flatbed scanner and
I have a circular patch right here.
If I were to take this patch and set it face down on the scanner,
and I were to start the scanner and move the patch
in the same direction as that moving row of pixels,
看看扫描结果 你可能想到了 它会是圆形的吗？
check out what happens, you are smart, is this going to look like a circle?
不 不是圆形的 而是被拉伸了
No, it’s not a circle, it stretched out.
And that makes sense right? You’re stretching
that image because you’re moving it along with the scanner.
Now, conversely what’s going to happen if
instead of moving it with the scanning row pixels we move opposite.
It’s not going to stretch it out is it what’s it going to do,
It’s going to compress that circle down
a rolling shutter on your cell phone camera is very much like this
is that it goes from the top of the image all the way.
All the way down to the bottom that means that
what you’re seeing is actually a lie,
it’s like a stack up of several different moments.
Okay now that we understand how this works,
it’s time to visualize in the most turbo awesome way possible.
Over the past three years, anytime I had
a phone and a high-speed camera at the same place at the same time.
I would be able to look out for rolling shutter events,
and I would video with the phone,
and then I would video with a high-speed camera,
so that I could go back and manually simulate rolling shutter
to let you understand exactly how the artifacts were created.
This is so stinkin cool.
Your brains going to get it instantly
we’ll start with iPhone video
and then we’ll go to the simulation “piu” result.
This is the first moment I realized I can fake rolling shutter.
I was in a terrible problem over the Australian outback
and I realized that the patterns would change as I rotated my phone.
I haven’t have a high-speed camera with me so I’ve gotten down
and I started collecting data.
This is what your camera does dozens of times per second.
I noticed that the patterns are very different depending on which way
the propeller rotating relative to the rolling shutter.
This is really beautiful, but I was kind of bummed that
I didn’t get to see the effect head on to the propeller.
Couple of years later though, when I was taking high altitude flight lessons
near Pikes Peak in Colorado.
I finally got my chance the video a propeller head-on on the tarmac.
The fidget spinner community has known for a while now
that when it’s really bright outside a cell phone camera videoing a fidget,
spinner will turn it into what they call the thing.
It’s just rolling shutter with a little bit of aliasing thrown in,
but it looks like some kind of ninja alien throwing star.
Anyway, when you slow it down with a high-speed camera,
you can really reveal the map that makes this look so weird.
My buddy been plays both the mandolin and the guitar,
and it took us a really long time to get the rolling
shutter effect to show itself.
But when we did, it was awesome.
– 哦 太牛了- 哦……快看啦
oh-hoooo, oh win, oh work will, oh.[ guitar music]
[ laughing][ guitar music]
Guitar strings are especially difficult because they vibrate so quickly
that a normal high speed camera isn’t fast enough.
We had to record them at 20,000 or 28,000 frames per second
to be able to run this simulation properly.
The last trick is something I had never seen before,
but somebody told me about.
If you video a coin spinning,
you can see a swirl pattern on the edge of the coin.
Yep, that’s also rolling shutter.
Obviously this took a really long time to make
and Henry from minutephysics made it possible.
He’s the guy that figured out exactly
how to make After Effects simulate rolling shutter.
All the behind the scenes video on the second channel Henry
and I talked about what we’re trying to accomplish.
Go check it out and moan will throw some love Henry’s way.
Also, once they thanks to the sponsor which is audible
before we talk about the book that I’m listening to an audible right now.
Let’s go goof around with rolling shutter and some chickens.
Okay, the book I’m currently listening to on audible
is called the devil in the white city.
it’s a really good book about the 1893 Chicago World’s fair,
a fair that I had no idea changed America, but it did.
Also America’s first serial killer, so there’s that.
It’s pretty crazy, I had no idea.
It’s a great story you should check it out.
Devil in the White City by Eric Larson.
If you will enjoy it,
you can get that by going to audible.com/smarter.
That is two things number one you get a free audiobook,
and number two I get secret internet points,
because audible knows you came from smarter every day
and they’re more likely to support smarter every day in the future
and that’s a big deal for me in the family.
I appreciate that.
Anyway, if you see anybody that talks about rolling shutter,
make sure they don’t get confused with aliasing, that’s the wagon wheel effect
a lot of people get those too confused.
I hope this video earned your subscription,
if it didn’t, no big deal.
I’m Destin, you’re getting smarter every day.
Have a good one, bye.
Last chicken, bright chicken.