Hey guys, what up.
My name is Serge,
and welcome back to my channel.
Today, we’re going to take a look at video frame rates,
what the differences are,
and hopefully help you decide
what frame rate to choose when filming.
First, let’s take a look at what video frame rate is.
As many of you might already know,
all video is is just a bunch of still images
played back in sequence.
When you play back these still images fast enough,
the human eye interprets these images as motion,
or video.
The minimum number of images
you have to display in one second
to look like video is 24, or 24 frames per second.
Anything slower than that,
and it just looks like a bunch of still images
played back really fast.
So once again,
you have to play back at least 24 still images
per second for it to look like video.
Most movies are shot and played back at 24 fps.
This is what we’re used to seeing in the movie theatre,
so thats why you often hear
that 24 frame per second footage looks cinematic.
It’s not as smooth
or clear as some of the other frame rates,
but it’s what movies look like,
so it looks cinematic.
Most TV shows and online content
is shot and played back at 30 frames per second,
meaning 30 still images are recorded
and played back every second.
This is probably the most common frame rate there is,
and easiest to work with.
Especially in the early days of television,
and even today,
most displays have either 60 or 120 hertz refresh rates,
meaning the image on screen
refreshes either 60 or 120 times every second.
A video clip recorded at 30 frames per second is simple.
Each frame is displayed on screen for two cycles.
A 24 frame per second clip on the other hand,
when played back on a screen
with a 60 hertz refresh rate,
has to be modified to 30 frames per second,
and each frame is once again,
displayed on screen for two cycles.
This is called a 3:2 or a 2:3 pulldown.
I’m not going to go too deep into this,
but basically to match the screen refresh rate,
some frames have to be displayed for two cycles,
and some for three.
To make this less noticeable,
frames are blended, which could cause minor artifacts.
Most displays today
do this well enough where it’s not even noticeable,
but still, you can see why 30 frames per second is easiest,
and used for most often for TV and online content.
If you film something with lots of fast movement like sports,
filming at 24 or 30 frames per second
might give you too much motion blur,
making your entire image look blurry.
Thats why most of today’s cameras
give you the option of recording at 60 frames pre second.
Recording 60 still images every second
also increases your shutter speed,
in turn reducing motion blur.
Now, you can just increase your shutter speed
at 30 frames per second,
but it still won’t look as smooth
and clear as clips recorded at 60 frames per second.
This frame rate works really good for fast action,
but can also be used for normal footage
like what I’m recording right now.
Normal clips recorded
and played back at 60 frames per second,
tend to appear both smoother
and sharper than 24 or 30 frame per second clips.
The extra frames make the image appear more lifelike.
Some people like this look, some don’t.
Personally I hate this look,
but like I said, some people like it.
It’s a personal preference.
Another advantage of shooting higher frame rate
is slow motion.
If you slow down a 24 frame per second clip,
even to 80 percent,
the image looks choppy.
But if you take a clip recorded at 30 frames per second,
and slow it down to 80 percent,
which still gives us our minimum 24 frames every second,
the video still looks smooth.
A video recorded at 60 frames per second,
can be slowed down even more,
all the way down to 40 percent of the original speed,
and still look good.
The higher your recorded frame rate,
the more you can slow down your clips,
and still play back 24 frames every second.
Now that we have a basic understanding
of recording frame rates,
let’s take a look at project frame rates.
When you edit your video in Final Cut Pro,
or any other NLE,
when you first create your project,
you have to select a frame rate.
This will be the frame rate
at which your finished video will be exported.
If you choose the same frame rate as your clips,
things are simple.
All the frames from your clip are played back,
and your video looks just like what you recorded.
If you start mixing frame rates,
things get a little more complicated.
In my media browser,
I put together three clips for demo purposes,
each with a different frame rate.
Every frame has a number,
played back in sequence.
First, let’s take a 24 frame per second clip,
and drop it into a 24 fps timeline.
If I go through the clip one frame at a time,
you can see each number is displayed
for one frame of the video.
Now, look what happens
when we add a 30 frame per second clip
to this same timeline.
Because the timeline is only 24 frames for every second,
we start skipping frames.
In this example,
every fifth frame is skipped.
In a video clip,
this results in a slight jump every 5 frames,
so the video will be jittery.
This is exaggerated even more with 60 fps clips.
Final Cut Pro has to skip even more frames,
and the video ends up looking choppy.
Let’s do the same test in a 30 frame per second timeline.
If we add a 24 frame per second clip,
to make up the extra frames,
every fifth frame is duplicated.
Once again, in a video clip,
especially with a lot of motion,
these duplicated frames
will make the video appear jittery.
Using 30 or 60 frame per second clips
in a 30 fps project, look considerably better.
A 30 frame per second clip
will look just like it was recorded.
If we use a 60 frame per second clip
in a 30 fps timeline,
every second frame is skipped.
But, because the frames skipped are consistent,
the video still looks smooth.
Same thing happens if your timeline
is set to 60 frames per second.
Using a 24 fps clip will duplicate frames,
but because the math doesn’t add up,
the duplicated frames aren’t consistent,
so the video will appear jumpy.
Using a 30 frame per second clip,
duplicates every frame,
and since it’s consistent,
the video looks just like a normal
30 frame per second clip.
So, as you can see
mixing frame rates is not ideal.
Some frame rates work better with each other
and are less noticeable,
and some are more noticeable.
Ideally, you should pick one frame rate,
and use it for both filming,
and your project frame rate.
If you have to mix frame rates,
to get the best results,
make sure the math adds up.
If you want your finished video
to have the cinematic look,
use 24 frames per second.
If you have to use the odd clip
filmed at 30 frames per second,
when possible, slow it down to 80 percent.
This way, you’re not skipping any frames.
For most of my videos,
I use 30 frames per second.
It looks good,
and I can always film at 60 frames per second
if I need slow motion.
This gives me the most consistent look
across all devices.
Like I said before,
some people prefer the look
of 60 frame per second clips,
but personally I don’t.
The image looks almost too sharp,
and too realistic.
The only time I use 60 frames per second,
is if I’m filming fast action like sports,
or I know I need to slow it down.
I hope this video shed some light for you
on different frame rates,
and when you should use them.
If you found this video helpful,
let me know in the comments,
or by hitting the like button.
And if you’re new here,
make sure to check out the rest of my channel
for more videos like this one.
New videos uploaded every week,
so hit that subscribe button.
Thanks for watching,
and I’ll see you back here nest week.