Table of Contents
- Shooting slow-motion footage and applying the effect on your editor
- How to shoot slow-motion footage
- How to post-process your slow-motion footage
- 1. Why did you choose slow-moving shots for this footage?
- 2. Do you have enough light?
- 3. Tripods are important
- 4. Focus manually
- 5. Avoid Lens Flare
- 6. Don’t overuse
Slow-motion footage and cinematic excellence are a match made in heaven. The reason for this is that nothing else brings movie magic like slow-motion.
Slow-moving shots are a trend that has been around for the longest time and its demand is not being dampened. It is one of the most used effects when it comes to video production.
They give the viewer a longer time of impact to process the emotion a clip is trying to convey. The slow-motion effect also gives attention to aspects of a video that may have otherwise been lost in translation.
Slow-motion videos also give a variety to your shots. They are normal footage shot at a higher frame rate and is played at a slower speed.
It is often thought that this effect is exclusive to fancy equipment and big screens. However, you can have the same cinematic effect on smaller devices as well.
New models of cell-phones are coming in with built-in high-resolution functions to execute a slow-moving-shots.
The question is how do you film slow motion on a DSLR. We have got you, here.
Shooting slow-motion footage and applying the effect on your editor
There is a stark difference between the two.
This difference between shooting slow-motion footage on your camera and just applying that effect on your editing software is what makes all the difference.
The former gives a genuinely smooth and slow effect while the later just renders a jittery, stutter-packed product.
In essence, applying the slow-motion effect in the post also gives you slow-motion footage.
However, it does not convey the same way as the gorgeous, believable and aesthetically charming clips with cinematic effects do. They are just not convincing enough.
There are a few things that you have to keep in mind in order to shoot cinema-quality slow-moving shots and to edit them properly using certain settings on your camera and editing software.
The reason for this is that they go hand-in-hand when you want to create some quality effect on your footage.
How to shoot slow-motion footage
Understanding the high frame rate in slow-motion footage
You have a number of frames per second that you shoot at when you are shooting video. With a still image, you are just taking one picture. Click. That is just one image. That image is called a frame.
However, with video, you are taking 30 images or 24 images every second which then you put together. That gives you footage.
The footage is a compilation of hundreds and thousands of images or frames just flying by your eyes.
A standard frame rate of 24 fps essentially means that you are capturing 24 images per second and then putting them together to get footage.
For a slow-motion video, you double or triple the frame rate you have more images per second and there are no empty spaces and abrupt motions when you stretch it out in post for slow motion.
This is how you maintain the quality of footage after having stretched it for slow motion.
However, you cannot just set a frame rate based on your preference. Different kinds of emotions make for different frame rates.
If it is a slo-mo of someone’s expression, 60 fps will do. But if you have a lot of movement in your shot and you want to show it like cars colliding or exploding, you may need a higher frame rate like 120 fps.
Understanding high shutter speed in slow-motion footage
The shutter regulates the amount of light that enters the camera removing any motion blurs. However, you need only just about a little motion blur to add a realistic touch to your body of footage. Otherwise, it would just look too sharp and artificial.
When the footage is to be played at a slower rate, like it will for your slow-moving shots, you might need to lessen this motion blur because every frame has more time to be looked at in slo-mo.
It is often thought that the right way to go about shutter speed is to set it double the frame rate. Well, that works for slow-motion as well.
If you are shooting at a higher frame-rate, don’t forget to also set your shutter speed double in the denominator of the frame rate. i.e. 1/120 for 60 fps.
It is possible that your camera does not have the exact double of the shutter speed as the frame rate that you are using.
For those gadgets, you can use the closest to the double shutter speed possible on your camera. For a frame rate of 60 fps, you could use a shutter speed of 1/125 if you do not have 1/120.
When you set your shutter speed as high as this for slow-motion footage, another thing you need to be mindful is the light that enters your camera.
If you are using natural daylight or a well-lit, it is fine. However, shooting in an indoor space in a poorly lit area, you may need to widen your aperture. You may also need to increase your ISO.
The dilemma here is that it may make your frames noisy and grainy. It is advised to shoot outdoors with tons of sunlight assisting your or to use loads of artificial light inside.
To correct the noise issue, you can always apply the Denoiser plugin in the post to eliminate the blurriness and the noise.
Different types of gadgets with different frame rates
GoPro has also upped their game in that department. You can shoot for a frame rate as high as 240 fps which is more than a lot of DSLRs.
However, at a frame rate this high, you must have a lot of movement happening in the clip, otherwise, a lot of images will come out empty.
A regular Canon model like a 1D X Mark II or an EOS 7D Mark II has a frame rate of 60 fps. It is a pretty decent frame rate to shoot slow-moving shots.
But you may want to go higher if you want to do a really good job. Sony Alpha or Black Magic takes you straight to 120 fps.
If you are new to the slo-mo area and are just learning, a simple frame rate of 60 fps will do.
The bottom line to all of this discussion is that a camera with a higher frame rate improves your chances of having flawless footage.
Shooting your slow-motion video using a DSLR
Using 24 fps is the standard for Hollywood cinema and pretty much what everyone out there is doing.
For a smoother look, some videographers like to shoot at 30 frames per second. More frames fill the gaps in the motion of the subjects for the camera
However, it really just depends on what project you are working on. The requirements of every project are subjective.
Hypothetically, you are shooting at 30 fps. This is what will be on our editing timeline on whichever editing software you are using.
If you want your footage to be processed into slow motion, what are you going to do? You are going to shoot at a higher frame rate than 30 frames a second.
So, if you shoot your footage at 60 fps and play it back at 30 fps, you are going to have footage that you can play at half the speed. This is how the math goes:
1 second of 60 frames = 2 seconds of 30 fps
That 2 seconds is slowed-down footage. If you want to expand a 1-second video for three seconds, you would want to use 90 fps.
The bottom line is that the duration at which you can elongate your slow-motion videos depend on what frame rate you are using to shoot a video in your camera.
How to post-process your slow-motion footage
Here is where things get a little tricky. Some cameras have a built-in slow-motion function. You can go to your setting and record the video in slow motion at a higher frame rate.
In other models, you may not have this built-in slow-motion function.
So, when you shoot at a higher frame-rate, you end up with footage of a normal speed because even though the footage was shot at a higher frame rate, that camera is playing the footage back in the same speed it was shot at.
There is a way around that. You can fix the speed of the footage in post-processing.
The editing timelines are pre-set to 24/30 fps. Most footage that you shoot at this frame rate works just fine on this timeline.
However, for footage that has been shot at a higher frame rate, you have to stretch it out to fit this timeline.
By doing that, we are turning one second of video into two or more depending upon the multiple of the normal frame rate of the timeline.
In Adobe Video editing software like Final Cut Pro or Premiere Pro you can just drop your footage in your 24 fps/ 30 fps timeline, highlight it, and press Command/Control+R on your keyboard.
Doing this is going to open up a retime menu on your editing software. Go to Custom, hit Automatic. Your editor will manually stretch the footage and you will get a video that is on a 30-fps timeline.
Whatever frame rate you shot this video on, divided by three. This coefficient is how many times your clip will be expanded.
Source: Jeven Dovey
If you shoot a video at a normal frame-rate and try to stretch it on a normal timeline, you will have some repetitive frames in place of the missing frames. Your export will look something like this.
You cannot expect that to be cinema quality now, can you?
This was all the technical stuff one has to be aware of, but enough with the math. Let’s move on to a more creative and execution aspect of slow-motion videos.
Here are some key pre-requisites that you need to check off before you start making slow-motion footage.
1. Why did you choose slow-moving shots for this footage?
When you start off with making slow-motion footage, you must answer this question to yourself of what actually is the objective behind you choosing this effect.
Often times, it boils down to two main reasons.
- As moments packed with emotions seem to last longer than ordinary ones, it makes sense to project emotions on the screen for longer in order for the audience to be able to absorb and understand it completely.
- The other is to lay stress on the impactful visuals that may have been missed otherwise and add great aesthetic value to your scene. A blink of an eye, a butterfly flexing its wings, raindrops landing on a flower petal, blades of fire escaping, etc.
You should have a solid excuse for using slow motion and not overuse the effect. Only use it at the points at which it makes sense to do so.
2. Do you have enough light?
You might have noticed one thing while watching TV or films. Most of the super slow shots take place in broad daylight. Not at night or dingy dark places.
The reason for that is you have to have ample lighting to be able to capture the motion. Once you keep your frame rate more than 300fps, lighting is pivotal.
So, if you have to shoot these shots, you have to do them in a studio setting with loads of artificial lighting.
You can use high CRI lights to bring that cinema magic. A light that flickers could mean disaster on screen. Even though they would work fine for any other scene, slow-motion footage can be potentially ruined by flickering lights.
LED lights are a safe bet because there is no chance of voltage fluctuation. It is because there are some models that need not be plugged in. to be plugged in for energy. However, be certain that you have checked every single light before go time.
Some people also use tungsten lights. They work for slow-moving shots to make sure that they are either over 2k or that you are using a power generator in order to keep flickering at bay.
All of this complication arises when you cannot use daylight because the sun is always a safer bet.
3. Tripods are important
In order to keep stability about shots and keeping your motions smooth, you need to use a tripod. Because when on screen, even a little destabilization can lead to a wobbly scene while making slow-motion footage.
Maybe you can do without a tripod in your shorter clips but for longer shots, you have a higher chance of vibrations. It is better to use one if you have it.
4. Focus manually
When you use autofocus, your lens starts to pulse in slow-motion footage due to the high frame rate. What it means is that your video will keep snapping in and out of focus intermittently.
Manual focus is slow-motion’s best friend.
5. Avoid Lens Flare
While shooting during the day, if your camera is pointed to the sun, you can end up with a substantial glare that can neither be covered up in the post, nor be ignored.
It is not just a problem in the day-time. You can also get flare from passing cars and other light sources. You can eliminate the danger of that happening by using a flat lens at night time.
6. Don’t overuse
Slow-motion is an effect that plays out on the sub-conscious level. If you overuse the function or use it in the wrong places, you are ruining the charm.
Filming is not an exact science, but one thing that stays is that it doesn’t do anything where it is not needed. As for slow-motion, it should just slide into the shot ever so subtly for a cinematic feel.
Less is more.
So, there we have it. Vows to the marriage of slow-motion with quality cinema. Now if you want to produce some cinema-quality slow-motion sequences, you have all the ammo you need. Happy filming!
Here is to hoping that this will help you create the best quality slow-motion footage. If you have any questions about the process, feel free to reach out to us.
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