DJI Mini 3 and 3 Pro Slow Motion Video Using Frame Rates VicVideoPic

The basic Mini 3 offer a maximum frame rate of 30 fps at 4k resolution and 60 fps at 2.7k and 1080p. The Mini 3 Pro has a maximum frame rate of 60 fps at 4k, it is, therefore, the only lightweight DJI model to offer real slow-motion capabilities at full resolution

Users interested in video with the Mini 3 and 3 Pro might find these articles useful

If You Prefer To Watch This As a Video

Why slow motion?

When shooting landscape footage far away from the target, which is often the case with drones, slow motion is not really useful. especially if there are no moving elements in the shot

But when the scene contains moving elements, we can add much more interest by slowing down the action. When we get closer to the action, slow motion becomes even more essential to convey a different mood to the scene

As you can see slow motion adds emotion not only to sports and action but also to people walking or dancing and even with waves, fountains, and waterfalls

You can see a few examples of slow motion applied to footage shot both with drones and ground-based cameras. Another spectacular effect is obtained by speed ramping: suddenly slowing down from regular speed to slow motion or the other way around

Choice of the Frame Rate

The most used frame rates are 24 or 30 frames per second, which are actually 23.976 and 29.976. Sometimes 25 fps is also used, but for the sake of simplicity, lets focus on the most used two, 24 and 30 fps

24fps is traditionally the one used in Europe, while in the United States, 30 fps is more common. Historically the different choices were due to differences in the frequency of electricity, 50 Hz in Europe versus 60 Hz in the United States

Nowadays 24 or 25 fps are the one used in most cases for cinema, while 30 fps is used mostly in TV news, sport, and reality TV

I will concentrate on 24 fps, as it is considered the most cinematic and also because it offers more options for slow motion. More examples of footage quality with the Mini 3 and 3 Pro are in this article, while this one is about night footage with these models

Before starting any project I set the timeline of my video editor to 23.976 fps, which means that I will be encoding and publishing at this frame rate

Why Higher Frame Rates

Many users ask if it is possible to simply slow down footage while editing to get slow motion

It is always possible to accelerate footage in post-processing without loss of quality. Still, the same is not true when slowing it down

The difference is evident comparing footage shot at the same frame rate of the project and simply slowed down in post-processing versus slow-motion obtained by filming at a higher frame rate interpreted in the frame rate of the project. Let me explain why

When shooting footage I will set the frame rate to the same value, 24 fps, unless I intend to do slow motion, in which case I will go for a higher frame rate, as we will see later

All other settings for video with the Mini 3 and 3 Pro are in this article

Accelerating footage

A very simple example: we have 4 seconds of footage shot at 24 frames per second, So a total of 24 multiplied by 4 equals 96 frames

If we want to double the speed we need 2 seconds of footage still at 24 frames per second, so 48 frames. We have plenty of frames available, all the software has to do is drop half of the frames and keep the 48 needed, so it can maintain basically the same quality

If we want to speed it up by four times we only need one second of footage. And again there are plenty of frames and the program will drop 3 frames out of 4

Slowing Down Footage

But if we want to slow down our 4 seconds clip to half speed, the software has to fill 8 seconds and needs 192 frames (24 frames by 8 seconds). But only has 96 so it needs to somehow create new frames and this is where the quality declines, whatever method we use.

The best way to slow down a clip is to start with a higher amount of frames. In our example, if we start with a 4 seconds clip shot at 48 frames per second which is double 24, we have a total of 192 frames

If we slow down the speed by half, we end up with an 8 seconds clip, since our project is at 24 fps. We need 24 x 8 seconds, which equals 192, we have exactly the frames we need

The best results are obtained when using a frame rate that is a multiple of the one used in the timeline so that all the frames are used. But other frame rates are sometimes used, for example, it is possible to shoot at 30 fps and encode at 24, in order to get a very subtle 20% slow-down effect which is used quite often in movies

But the software has to create one frame out of five. This can cause small artifacts, but the result is good enough for most non-professional usages

Another possibility is to use 60 fps for a 60% slow-down effect, in this case, some frames will again be extrapolated

Frame rates in the Mini 3 and 3 Pro

The basic Mini 3 offer a maximum frame rate of 30 fps at 4k resolution and 60 fps at 2.7k and 1080p, therefore it doesnt have any real capabilities for slow motion at the highest resolution.

On the other hand, the Pro model has a maximum frame rate of 60 fps at 4k. This is a significant feature in favor of the Mini 3 Pro for users seriously interested in shooting footage, as it is the only DJI lightweight model to offer real slow-motion capabilitiesat the highest resolution

By choosing the option slow motion on the video menu we can get a frame rate of 120fps at 1080p for a super 5x slow motion. The 120 fps is automatically slowed down and doesnt need to be converted in the frame rate of the timeline.

Sadly there are a couple of limitations in the use of frame rates above 30 fps

When shooting for slow motion, in some cases we want to track a subject, but the intelligent flight modes are only available up to 30 fps, including Active Track and Spotlight, the two most useful ones for tracking

The zoom capabilities at 4k resolution and frame rates higher than 30fps are not available. I hope that upcoming firmware upgrades will solve both limitations

Editing Slow Motion Footage with the Mini 3 Pro

The process to get slow motion from a higher frame rate is quite simple and it is similar in most video editors. Here I will be showing how it works in Premiere Pro, probably the most widely used. I will show two different methods to make sure that your editor contains at least one of them

After dropping the first clip in the timeline, the frame rate of the project is set by going to Sequence, Sequence Settings, and at the top, we choose the Timebase at 23.976

If we drop in the timeline a clip shot at 48 fps, double the frame rate of the project, it still plays at normal speed, we need to slow it down to half speed and there are two ways to do it

The more flexible one is to go to the icon of the clip on the window at the left, right-click on it and choose Modify and then Interpret Footage. Then in Fram Rate, we select Assume This Frame Rate and enter 23.976

The clip now plays at half speed as 48 frames are played at 24 fps speed, which is exactly half. The original frame rate of the file is kept in memory and can always be retrieved if needed. This can be useful when working on a project with plenty of files with different frame rates

It is also possible to batch modify several clips by selecting them, right-clicking, and choosing Assume This Frame Rate

Another method that can be used is simply right-clicking on a clip in the timeline and choosing speed duration

We are presented with this window where we can enter the desired speed. In this case, we have a 48 fps clip and we want to slow it down to half speed, so we enter 50%, the duration of the speed displayed just below will double

When using this second method we must enter the correct percentage of speed reduction according to the frame rate at which the file was shot

Assuming, as usual, a timeline of 24 fps, if the footage was shot at 30 fps we must enter 80%, for a file shot at 48 fps enter 50%, for one shot at 60 fps, enter 40%

Note that when we shoot with the Mini 3 Pro in slow motion mode, therefore at 120 fps at a resolution of 1080p, the file is automatically interpreted and we dont need to reduce the speed

Higher Frame Rates Should Be Used Only for Slow Motion

Some people may ask: what about shooting always at 60 fps just in case we should decide to slow it down at a later stage since it is possible to use the 60 fps footage at normal speed?