Step-by-step

Combine different sizes and frame rates

1 Import clip

Choose File>new Event. Label it ‘Combine’. Choose File>import Media. Browse to our clips – Drone.mov, Harbour and Lighthouse. Click ‘Import Selected’.

2 Call the Inspector

Click on the Drone thumbnail. Tap the spacebar and the clip will play smoothly. In the Info Inspector, the clip’s Frame Size is 1920 x 1080. Its Video Frame rate is 29.97.

3 Examine size and rate

Click on Harbour. The Info Inspector tells you it is 1920 x 1080 with a lower frame rate of 25 fps. Lighthouse has the same 25 frame rate but a Frame Size of 3840 x 2160.

4 Choose a project size

As most of our project’s clips have a size of 1920 x 1080 and a frame rate of 25, drag Harbour to the timeline. This creates a 1920 x 1080 project with a 25 fps frame rate.

5 Add drone clip

Drag Drone in. You’ve added a clip with a higher frame rate of 29.97 fps to a project set to 25 fps. The Drone clip now plays back jerkily as some frames have been removed.

6 Add third clip

Add the Lighthouse clip. Although this is 3840 x 2160 it scales down to fit the smaller 1080 project size with no drop in quality. There’s no jerking as the frame rate is 25 fps.

7 Frame blending

To smooth out the Drone clip, click on it in the timeline and then click on the Video Inspector icon. Scroll down to Rate Conform and click the Frame Sampling dropdown.

8 Optical flow

There are several ways to reprocess a clip so it matches the project’s frame rate. Choose the most powerful – Optical Flow. Final Cut will then analyse the clip’s frames.

9 Test the clip

After analysing the jerky clip for optical flow Final Cut blends the frames so they run smoothly with the project’s 25 fps frame rate. Tap the spacebar to play the blended clip.