Today's video is gonna look a little different
than my other ones, because I'm filming
and uploading it in 60fps.
I'm doing this so that I can provide samples
demonstrating the pros and cons
of mixed frame rate video projects,
which is today's topic.
Let's get Undone.
[offbeat music]
♪ Gerald Undone ♪
♪ He's crazy ♪
What is happening, everybody? I'm Gerald Undone,
and today we're talking about frame rates.
Now, this video isn't gonna be about
which frame rate is better,
or if we should still be using 24p.
In fact, Filmmaker IQ already covered
that topic brilliantly on their channel,
so I recommend you check that video out.
Instead, we're gonna be tackling a topic that is asked
over and over again in forums and comments:
what happens when I put X frame rate footage
into a Y frame rate timeline?
The format for this video is gonna be really simple.
I've got about a dozen video clips
showing various frame rate combinations.
They're all of the same panning shot
executed at the same speed,
and we're gonna be breaking down the pros and cons of each,
and debunking some of the more common myths about them.
So, let's get started with the first example,
which is how this video is recorded:
60p footage into a 60p timeline.
As you can see, this clip plays back rather nicely,
and I chose this one to start because it'll be our control.
And when I say "plays back nicely,"
I mean that the image doesn't stutter
when moving across the screen.
This judder is caused by a few factors,
including the refresh rate of the screen
you're viewing this video on
as well as the actual speed of the pan.
For each of these examples, one of the factors
we're gonna be discussing is the panning speed.
Now, I conducted the pan at the same speed
for all of these examples, which I based on the slowest
frame rate that we're gonna use, which is 24p.
The slower the frame rate you shoot in,
the slower you need to pan or move the camera
in order to prevent that stuttery look.
There's an old rule that suggests that you should pan
no faster than a screen width every seven seconds,
and that's a decent start, but it doesn't account
for the other factors that we just mentioned.
There's a good resource from RED,
if you didn't know already,
that calculates your ideal panning speed.
I'll put a link to this calculator
in the description, but it looks like this.
So, first, you choose your sensor size.
Now, this directly relates to the focal length
for determining your angle of view,
which is obviously important,
because your total angle of view will determine
how many objects are in the frame
and how far they're moving when you conduct your pan.
Now, I'm gonna put in 32mm for my focal length,
because I shot these clips on a 16mm Micro Four Thirds lens,
which is about the equivalent angle of view
of a 32mm full-frame lens,
and the RED Monstro is a full-frame sensor.
And then you put in your frame rate, which, like I said,
I based it on the slowest frame rate I'm gonna use,
which is 24p, that's how I timed all the shots.
And then you do your panning angle.
No, the panning angle is how far
you're gonna move across the frame.
So, if you went pole to pole like this,
that's gonna be 180°, and then half of that
would be 90, and so on.
So, for an arc about like this, that's about a 45° pan.
So, when we put that into the panning angle,
it will generate our panning duration over here,
which is 8.9 seconds.
That's how long you need to spend to get across.
So, if you count it in your head,
you'd want to count to at least nine,
going from the start of the pan to the completion
of the pan, if you're gonna cover 45°
with all these settings.
And that's exactly what I did when I conducted these tests.
Now, if you increase the frame rate,
the time required goes down,
because there's gonna be more frames to work with,
so you can do it faster
and the footage will still be less jerky
because it'll have more frames to fill those in.
So, if we bump it up to 60fps,
it'll have a suggested panning duration of 3.6 seconds.
Now this makes sense because 3.6 is 40% of 8.9 seconds,
and 24p is 40% of 60p.
Being able to pan faster can be advantageous
if you need to tightly control the duration of your project,
or if you need to follow fast action,
but things get a little bit different
when we drop that footage into a slower timeline.
So, let's jump back to the 60p footage
on the 60p timeline combination
in order to refresh your memory,
but I'll also be putting timestamps
to all these samples in the description below,
so after the video if you want to jump around
and re-watch some of them, you'll be able to do that.
So, this sample is smooth,
and we could even bump up the pan speed
to the fastest of the three of them if we wanted,
and it would still be smooth. The shot looks nice.
Overall, this is a good result.
Now, if we drop that same 60p clip into a 30p timeline
without slowing it down, it looks like this.
Still pretty decent, but it's slightly worse
because any shakes or jumps have the potential
to be worsened by frame dropping.
When you put 60p footage into a 30p timeline,
it just throws away half of the frames
in order to make it fit, and this mostly looks good,
but if you do happen to have any unwanted movement
followed by a dropped frame,
it can make the unwanted movement more obvious
and give it a more jarring effect.
But on a perfect pan, it'll be hard to tell
the difference between the two.
But another consideration to make is that
if you shoot a pan at 60p
but you intend to just drop frame it into a 30p timeline,
you have to pan at the speed required for 30p, not 60p.
So, if we jump back into the RED panning speed calculator
and we change the frame rate to 30fps
and hit "Calculate,"
we're gonna need 7.1 seconds in order to conduct that pan,
even though we're shooting at 60p
because we're gonna be throwing out half of those frames.
Despite that, though, I would still say
that 60p into a 30p timeline produces a good result.
Now, something we can do to prevent
those more stringent requirements
is to slow the footage down to half speed.
This will use all 60 frames rather than dropping
some of them, but it'll take twice as long to play back.
And this increased duration is the only con,
because it pretty much improves the footage
in every other way, if you're OK with the aesthetic.
Those shakes and bumps I was talking about
will actually be reduced
because it'll be in slow motion,
so they'll be less noticeable, and the pan speed
will go back to the normal 60p pan speed of 3.6 seconds,
because once it's slowed down,
the video clip will be 7.2 seconds,
so you'll be hitting the pan speed required for 30p.
So, you'll end up with similar smoothness
to 60p footage on a 60p timeline,
but with reduced camera shake impact,
but you'll have a dreamier slow motion effect.
But overall, I would say that this is a good result.
Now if we put that same 60p clip into a 24p timeline,
we'll really start to experience
that judder I've been talking about.
And not only that, but you also need to use
the steadiest and slowest pan speed of the three.
Now, the reason why the stuttering is increased
is because it doesn't divide evenly into the timeline.
When 60p went into 30p, you just dropped every other frame.
But to go into 24p, you have to drop every 2.5 frames.
And then to play it back on your standard
60 Hertz display, that footage has to then
be reorganized back into a base-30 configuration,
and this process is known as a 2:3 or a 3:2 pull down.
But regardless of that, generally, putting 60p
into a 24p timeline at 100% speed
does not produce a very good result.
Now, we can minimize some of the issue of displaying
24p content on a 60 Hertz display
by panning at the correct speed
and by using ideal frame rate combinations,
but we can't remove it completely.
The only way to remove the display base judder
is to actually show this on a projector
capable of flashing 24fps,
or by showing it on a display
that's capable of reversing the pull down smoothly internally.
Some higher frame rate displays,
like 120-Hertz models, do have some mechanisms
for dealing with 24p because it does divide evenly from 120.
However, when it comes to movies,
these modern displays using these techniques often
will kind of remove the aesthetic that the filmmakers
had in mind because that can only be achieved
when actually viewing it at 24fps.
So, in essence, we can do our best,
but when it comes to watching this on,
say, YouTube, you can never really get 24p content
to look quite good as it will on a 24p projector.
So, for the majority of users with typical 60-Hertz displays,
you'll need to combat that judder by avoiding
the bad frame rate combinations that we're about to cover.
But one of the ways that you can improve
the 60p on 24p combination is by slowing it down,
just like we did with the 30p timeline.
Now, I want to touch on something real quick
that I've read on a few forums
when it comes to interpreting footage.
Depending on the NLE used to edit video,
this may differ for you,
but when it comes to Premiere Pro,
there's basically two ways
to slow down a 60p clip into a 24p timeline,
or any timeline combination, for that matter.
You can right-click on the 60p clip and then choose "Modify,"
and then "Interpret,"
and then here you type in your timeline frame rate,
so in this case, "23.976 for 24p,"
and then you just drop it in the timeline.
However, you can also just drop it in your timeline
without interpreting the footage
and then change it afterwards using "Speed/Duration."
If we right-click on the imported clip
and then go to "Speed/Duration"
and then change the speed to 40%,
it'll produce the same result as interpreting it
as 24p, because 24p is 40% of 60p.
I've seen some debate in the forums about this,
but I'm here to settle the dispute and say:
they are the same thing. They produce the same result.
But I actually prefer the Speed/Duration method
because it allows me to fine-tune it by percentage,
and it allows me to do speed ramps and other fun tricks.
Anyway, so if we slow the clip down to 40%,
this will remove the majority of the stuttering
that we saw when it was at 100% speed.
It also once again reduces the impact of any camera shake,
because we're in slow motion, and you can also go back
to the panning speed of 60p instead of the slower 24p one.
Only do this, of course, if you know
that you're gonna be slowing it down for a 24p timeline.
And slowing it down like this will take it
from a bad result into a good result.
The other speed option you can choose is 80%.
80% will give you a usable frame rate of 48fps--
60 times 0.8 is 48--
and this is evenly divisible by 24,
much in the same way that 60p goes into 30p.
You just drop every other frame.
This means you'll have a pretty smooth shot,
and you'll be able to pan a little bit faster as well.
This will create a bit of a different look
than the 40% speed.
40% is more like real slow motion,
where 80% is just kind of dreamy,
not completely slowed down, but just a little bit calm
and relaxing like that, kind of like a music video.
And you will have a little bit of reduced
noticeability on camera shake.
Overall, I'd say this is another good result.
Now, the 80% trick can also be used for 30p footage
on a 24p timeline, because 80% of 30 is 24,
and it's the only way that I would ever insert
30p footage into a 24p timeline.
Because if you leave it on 100%, it looks like this.
There's terrible judder, and you still need to pan
at the 24p speed, and the camera shake
is worsened by dropped frames.
This is the worst combination of higher frame rates.
Terrible result. If you slow it down to 80%, though,
you can pan at a faster speed, you can pan at a 30p rate.
And again, it does reduce some of the noticeability
of camera shake, but you do have that dreamy,
music-video-like look that we were just talking about.
But overall, I would say that this is a good result.
Lastly, when it comes to 30p, you can obviously insert it
into a 30p timeline, which is a good result.
It's just not quite as smooth as 60p into a 60p timeline
because there are fewer frames,
so you're gonna have to pan at the regular 30p rate,
but it does produce a clean result
which works really well on standard 60-Hertz displays.
The same is mostly true for 24p footage in a 24p timeline.
This is the standard of the movie business,
and creates that film-like quality that people gush about.
This is how I shoot the majority of my videos,
mostly because I prefer the aesthetic,
and also because it's more efficient
for storage and exposure.
In fact, you might have noticed that
the image to this video is noisier than my regular videos
are because I had to compensate exposure-wise
for the increased frame rate and thus shutter speed.
So, that's definitely an advantage
to using a slower frame rate like 24fps.
However, 24p does suffer from two of the cons
that we've been mentioning:
one, it doesn't look as smooth on a standard 60-Hertz display
because of that repeating frames
and 3:2 pull-down thing we were talking about,
and two, it requires the slowest
and steadiest pans to look good.
And that's why in a lot of movies,
the establishing shots will be slow crawls
into the frame instead of pans.
Basically, 24p produces a great result if done correctly,
but not so great if done hastily.
Now, we're not going to be covering 120fps in depth
because basically everything I said before can be applied
to inserting 120p into slower timelines.
The only difference is that the speed adjustments
are gonna need to change.
You can obviously pan the fastest of the lot at 120p,
and when it comes to slowing it down,
you would use 50% speed for a 60p timeline,
25% for a 30p timeline,
and 20% for a 24p timeline.
And another advantage for 120p
is that it's divisible evenly by all three of those numbers.
Now, for the sake of being thorough,
let's cover the reverse.
What if you insert 24p footage
into a 30p or 60p timeline?
Well, the result is bad,
because the required frames just aren't there.
It doesn't matter how slow or fast you pan,
it will always jump and stutter.
The only way you can get away with it is
if there's very little motion in your scene,
but for almost every other purpose,
you're gonna want to avoid doing this.
So, that's pretty much it when it comes
to the functionality of these combinations.
But just because a combination produces
an acceptable result technically
doesn't mean that you're gonna want to use that
in all or any of your projects.
Just because 60p in a 24p timeline at 80% speed works,
doesn't mean it's gonna produce the look that you're going for.
And that's the part that
you're gonna have to decide on yourself,
and that's always been one of the biggest trade-offs.
Take viewing content on the web, for instance.
30p will definitely produce a smoother result
when it comes to playing back on standard devices,
but 24p has that aesthetic
that's mostly lost at higher frame rates.
So, my advice is to have a plan.
Use this video as a guide to know the limitations
of the different frame rate combinations,
but then plan out your shots accordingly.
You don't want to get stuck with mismatched footage
that you're gonna have to apply
unwanted speed adjustments to just to fit it in.
Like they say in carpentry: measure twice, cut once.
But that's gonna be it for me.
I hope you found this video helpful,
or at least entertaining.
And if you did, make sure you leave it the old thumbs-up
and consider subscribing if you haven't already.
But if you did not find this video helpful or entertaining,
feel free to hit the dislike button twice.
Alright... I'm done.