How to Combine different resolutions

1 Choose a resolution

On your iOS device, go to Settings > Camera > Record Video. The 1080p HD at 30fps default balances high-quality footage without filling up your phone. 1080p HD at 60fps creates larger files, but their motion looks smoother.

2 Compose your clip

Use a tripod, such as the Manfrotto Pixi mini with a phone clamp (pictured). As well as producing stable footage, a tripod will help you check how the image is composed. This can lead to more professional-looking clips.

3 Capture some clips

Feel free to change the resolution when capturing different subjects. A 4K size will suit wide shots, as you can zoom into specific subjects while preserving quality. Drop to 720p HD if you run short of storage space.

4 Slow motion settings

To capture moving subjects – for example, an engine’s billowing steam – in a creative way, go to Settings > Camera > Record Slo-mo. 720p HD at 240fps will capture a very smooth and slow version of any fast-moving subject.

5 Import clips

In iMovie on your Mac, click iMovie Library (left pane); choose File > New Event and name the event. Connect your iPhone to your Mac using its USB cable. Go to File > Import Media, browse to your iPhone, then choose Import All.

6 Create a new movie

The clips will be imported from the iPhone. Slo-mo clips are indicated by a circular icon (at the top left of their thumbnails). Click Projects (top left of the window), then Create New and choose Movie. A new timeline will appear.

7 Set project size

The clips in your event will be of various resolutions. Drag a 1080p HD video from the Media Browser into the timeline. Afterwards, click Settings (under the Viewer) to confirm the project is 1080p – see Genius Tip, top right.

8 Add clips

Clips you add to the timeline will be scaled to 1080p. 720p slo-mo clips might look a little soft due to them being upscaled to 1080p. 4K clips will look sharp, even if you zoom into them manually or apply the Ken Burns effect.