CD / Frame Rate - YouTube

This is a still picture!

This is a slightly different still picture.

If we switch between them quickly, it kind of looks like I'm moving!

If we add more pictures, it starts to look like realistic motion.

That's how animation works! But it's also how anything moves on screen.

The pictures don't have to change that fast for us to perceive the illusion of motion.

But somewhere around 20 a second makes it feel less annoying when watching for long periods.

And the pace doesn't have to be perfectly even - but if we want the recorded movement to play back in its natural,

real world speed, and stay in sync with other things, like sound,

it helps to keep the frame rate constant throughout the process.

A long time ago, the entire world settled on

24 frames per second as the standard for motion pictures.

It wasn't too hard to control the speed of film cameras and projectors by governing their motors with crystals.

But the invention of television transformed moving images into electrical signals.

So electricity itself had to keep the frame rate steady.

This was done by distributing the frame information evenly into the cycles of alternating current.

In parts of the world where AC power modulates at 50Hz, the frame rate was adjusted to

25 frames per second, places where it modulates at 60 Hertz had to raise the frame rate up to 30.

Which looks like this!

And for one place, the introduction of color to video caused slight Interference with the audio signal,

which showed up as occasional dots for those few still watching on black-and-white TVs.

So of course the government slowed down the broadcast frame rate by 0.1 percent,

and keeps it that way to this day.

Which is weird, because the reasons for this awkwardness are long gone.

Wires and radio waves no longer carry raw analog signals, but packets of digital information.

Everything about the picture, including the frame rate at which it should be played is bundled along,

and decoded by the device showing the video.

It's a frame rate revolution! Want to film at 12 frames per second, but play back at 18? You can!

Want to film at 90 and play at 24? Go for it.

But it's also a frame rate catastrophe. As automatic video encoders convert files from one frame rate

to another without the users even thinking about it, the internet drowns in footage with stuttering motion,

messy interpolated frames, and interlacing artifacts.

Hey, what if we shoot at double the standard film frame rate, and then play back at that same rate too?

The motion would have twice the temporal resolution, and feel twice as smooth!

Some people are into high frame rates and see it as a logical upgrade

to the classic 24 frames per second of movies, which can seem a bit choppy by comparison.

Some even advocate a rate of 60 frames per second, which is as fast as most monitors can refresh.

They see it as the future, not realizing that most of us have been looking at

50 or 60 interlaced fields per second on TV screens for about 70 years.

A few people claim they're sensitive enough to spot the difference between 48 frames per second and 60,

but I'm not sure that's true. I mean, I've been switching between the two rates randomly

in the last few shots of this video and I doubt they noticed that.

Today, frame rates are an aesthetic choice.

And aesthetics differ between mediums and genres.

Most filmmakers continue to use 24 frames per second for movies and drama TV,

while news and reality shows broadcast at 25, or 30.

Sports, video games, and VR applications choose 60 or higher for a lifelike experience,

and on the Web, creators experiment with all sorts of presentation styles over time.

You don't have to pick and defend one frame rate. Just be aware of them.

Especially when you convert video files.

Seriously, they look so lame exported in the wrong way.

If I searched for a clip from The Adventures of Pete and Pete,

I expect it to be at 23.976 FPS, with the 3:2 pulldown removed on a shot-by-shot basis,

and cross cut half frame fields compensated for. And I'll tell you something else—