The iPhone Duo can show the person you are photographing what the camera sees. A feature called Duo Preview puts a live view of the main camera's frame on the outer display, for both photos and video.
With Duo Preview on, the outer display mirrors what the main camera captures, so it works like a mirror rather than a viewfinder. The outer display shows only the preview, with no camera controls on that side. Subjects can fix their pose, hair, or costume before you shoot.
To turn it on:
- Unfold the iPhone Duo so the inner display faces you.
- Open the Camera app.
- Tap the Outer Display Options button (a column view icon) in the top-left corner, then tap Duo Preview.
- Point the rear cameras at your subject.
Tap the shutter button for a photo or Record for video. Either volume button or the Camera Control also triggers the shot.
The design choice worth noticing is the split of jobs. On a single-screen phone, the person behind the camera is the only one who sees the frame, and the controls share that glass with the image. Here the photographer keeps the controls on the inner display, while the outer display is given over entirely to the subject's view. Leaving controls off the outer side is what makes the mirror comparison hold up.
Duo Preview is one of several camera features built around the Duo's foldable design, alongside Kid Cue and Smart Take.