in this episode we talk about frames and frame rates again some pilasters
of filmmaking.
To explain these concepts I will take advantage of some visuals from a video
editing software, Premiere Pro. What you're seeing here below is called a
sequence; in video editing this is a container of your video and audio
material, the area where you actually cut and stitch the clips together to create
a video. Keep an eye on it as we carry on with the explanation. So what is a frame?
And here I would actually rephrase the question into "what is a video"?
A video is essentially a sequence of images photographs played one after the other
at a certain speed, a speed that gives the illusion of motion. Each of these
images is called frame; this is a frame, and another frame, and another, and so on,
you get idea. Now, the speed these images are recorded or played at is called
frame rate and it can be measured in FPS, which stands for frames per second. Let's
take this example: we have one man walking from point A to point B. To walk
this distance the man takes five seconds. If we film this action at one frame per
second, then we would only have five photos of the man during this period of
time, so one second, one photo. And now I want to show you an actual video at one
frame per second, check it out.
I wouldn't definitely win an Oscar for that film. Maybe I would. Let's go back to
our working man and this time let's say we want to record him at 8 frames per
second; that means that we're adding other seven images at our previous
example in the same amount of time of one second; let's now watch our motocross
video at 8 frames per second. As you can see we can still spot each individual
image in it. If we increase the frame rate to 12 frames per second then we're
going to reproduce that kind of Charlie Chaplin's
movies effect, where the character still didn't move as fluid and movements
don't look natural because still there are not enough frames per second to
reproduce a realistic motion. So here comes our bike rider again at 12 frames
per second.
After more or less 10-12 images per second the human visual system can
perceive each image individually while at higher rates then we can start seeing
those images as motion and that's when the standard 24 frames per second was
introduced. Let's check our video now again at 24 frames per second notice the
difference.
This is again more or less the lowest amount of images that to our eye and
brain reproduces a motion as we see it in real life and this frame rate has been
used in probably all the films you have ever watched in your life, apart from a
few of them. You're actually watching me too at 24 frames per second right now.
Apart from the 24 fps in the current days there are other two standard frame
rates used around the world which come from television and cinema: the 25 fps,
which is associated to the PAL system, which stands for phase alternating line;
this is the standard broadcast format in Europe, Oceania ,Africa South America, and
parts of Asia and that plays 25 frames per second or multiples of 25. The second
is the 30 fps, to be exact 29.97 frames per second and multiples of
30, which this time is associated to the NTSC system, which means national
television system committee; this is the standard broadcast format in North
America. There are cameras out there called high-speed cameras capable of
recording thousands of frames per second, like this video.
But most of the digital devices today, including smartphones, offer all those
frame rates we talk about it above and can record 48, 50, 60, 100, 120 frames per
second, which is very useful when you want to do something in slow motion, for
example. Check this video I filmed at 120 frames per second.
So, when you film at a high frame rate, basically you're filming a lot of images
in a tiny amount of time, a feature that allows you to stretch the time during
the video editing process, making it run slower than in real life.
The opposite effect of slow motion can be achieved with time lapses where,
instead, you're recording a tiny amount of frames during a long period of time
and in this case we're making the time go faster than its natural course.
in this example I filmed one frame every five seconds of actual time. Here's when
mathematics come in useful; basically to cover 10 seconds of actual video, in a
project at 24 frames per second, I had to leave my camera recording for 20 minutes.
Now, I'm sure you're gonna ask, "okay, that's all good but how do I actually
choose the frame rate for each project I'm working on?" Well, that depends on
different factors and we're going to talk about it in another episode.
More explanatory videos will also come related to motion blur, shutter speed and
slow motion, which are closely related to the frame rate. Well that's it for today,
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If you have one minute I would appreciate if you could leave a comment saying if
you have learned something new or if you enjoyed the video. I will see you next
week. Thanks for watching and God bless you.
Ciao