How to shoot SLOW MOTION
How to do proper slow motion
Today I’m talking about slow motion and how you do it right so you footage looks epic.
To understand slow motion you first need to understand how video works in general. When we talk about frame rate we’re talking about the number of frames per second. So when you hear 24p that means there are 24 images being taken every second by your camera. The standard for video is either 24p and 30p . 24p will give you the more cinematic look because this is the standard frame rate for Hollywood cinema.
To create slow motion footage what you're doing is adding more frames per second than what you’re playing back at.
For example if I shoot at 60 frames per second and play that back at 30 frames per second your footage will play back at half speed. This is happening because you shot 60 frames in 1 second but playing back at a rate of 30frames per second. This gives you 2 seconds of finished footage at 30 frames per second.
I’m going to show you two ways you’ll get slow motion in your camera.
First is with my Sony RX100v. If you go into the frame rates you’ll see, 60p, 30p 24p and 120p. So thats now many frames per second you’re going to record. We want the slowest at 120p which is 4x slower than 30p.
So now lets shoot a clip at 120fps and bring this into our editing software. I’m going to drop this on my timeline and play it back. Now wait a second, thats not slow-motion. And this is what happens with a lot of cameras. You are recording 120 frames per second but you’re making a 120fps file not a 30 frame per second file. So what you have to do is manually slow down your footage in your editing software so that it plays back at 30 frames per second.
For Final Cut X this is easy. First make sure your editing on a timeline that is 30fps or 24fps. Now bring in your shot and hit CMD + R. This will bring up your “retime editor” on the clip. Now you click on the custom tab and hit automatic. FCPX will now automatically stretch your 120p clip so that its timed perfectly for your 30fps timeline and now you have slow motion.
If you need to do this manually then take your shooting fps which in this case is 120 and divide that by your timeline frame rate in this case 30. So its 4 which means that you slow down the footage to 25% speed.
Now lets talk about the other way you’ll record slow motion. The Panasonic GH5 allows me to shoot 180 fps. However, when you go into the menu for frame rates you won’t see 180fps. It has a feature called variable frame rate and many cameras will have this option now. So for this I will select the frame rate that I want my footage to end up as. In this case HD 30fps. Now I’ll go into my menu and find my variable frame rate menu. Here I can turn on variable frame rate and select what FPS I want my footage to be shot at. The cool thing about this is that when you turn this on your footage will be shot at 180fps but it will be auto slowed down in camera so that it plays back at 30 fps. Now when you drag this clip into your timeline you don’t have to do anything to it to have slow motion.
One downside with Variable frame rate is that you are not going to record any audio. When I vlog sometimes I’ll forget to switch of the variable frame rate and I’ll shoot everything in slow motion which makes a whole sequence unusable. If I was shooting on the Sony at 120fps then I’d still be able to use it because its capturing audio. Just make sure you check your settings if you’re using Vaibable frame rates before you shoot because you don’t want your entire shoot in slow motion by acciedent. Imagine telling your client that the whole interview is unusable..
Some cameras only have 60p options which will give you a little slower than half speed when played back. However, there are cameras that go much higher. You’ll see some have 120, 240, 400, and specialized cameras will have frame rates in the 1000’s. Thats how you get a shot of a balloon popping or bullet firing in slow motion. Those cameras are made to do slow-motion at these high frame rates.
Lets chat about how you can do slow motion improperly. If you shoot in 30 fps and want to slow it down you’ll try to stretch the footage to play back slower but what will happen is you’ll get choppy looking footage. Its not slow motion when you stretch it. Basically your editing software has to fill in frames where there is gaps. So what it does is just multiply the frames that are there so a frame will be just be on screen longer which gives you a choppy look.
There is one piece of software called Twixtor that auto generates the missing files between frames when you slow down normal speed footage. This software looks at the two frames on either side of the missing frame and tries to create a frame to fill the void. This sometimes works amazing and you can get great looking slow motion however it also doesn’t work. It all depends on the footage that you shot. If this is something you’re interested in then I’ll put a link in the description below.
So that is my complete breakdown of slow motion. To get proper good looking slow motion you need to shoot at higher frame rates than the frame rate you are playing back at. This is limited by what frame rate you have in your camera.
Your homework right now is to go through your camera and find what frame rates your camera shoots at. Also find out if your camera has a variable frame rate or high frame rate additional setting. Play with all the frame rates available and see what you like working with best.
Let me know if you have any questions about shooting slow motion in the comments bellow. If you new to this channel make sure you hit the subscribe button. I’ve got a ton of filmmaking tutorials and camera reviews. I also create some fun vlogs from my travels. Also make sure you check out my Online Creator Film School. I’ve put together an entire course on how to make a career out of filmmaking. I teach you everything that I’ve learned from starting my own production company and making money doing it. Guys that is it. I will see you on the next one!