What I Found
Fit, Fill, or Stretch?
A bigger unfolded display does not automatically mean a movie will fill it. The open iPhone Duo is closer to a square, while the movie is wide. In this visual guide, I use a 16:9 scene to show what happens when those shapes meet: keeping the entire picture leaves some screen space unused.
Fit keeps the lighthouse, van, and sailboat in view. Fill makes the van bigger, but the landmarks at the sides disappear. Stretch takes a different approach and changes proportions: a circle becomes an oval. The wider 2.4:1 example makes the cropping tradeoff even easier to see.
There is another wrinkle: black padding can already be part of the video file. Fitting that whole file can leave additional space around it, so zooming is not always a clean fix. The Safari example uses our own clip in the Duo Simulator. It shows that page playback and the full-screen player can use space differently; it is not a physical-device or third-party streaming-app test.
What this video covers
- How movie and display shapes create unused space.
- Fit versus Fill, using the same scene and visible edge details.
- Why stretching distorts objects instead of preserving their proportions.
- A wider movie and padding already embedded in a video file.
- Safari page and full-screen playback in the Duo Simulator.
The short version
I would start with Fit and compare the edges before choosing a larger view. Check whether zooming removes a face, subtitle, or detail you care about. Keep the whole picture when those details matter; use Fill when you prefer the bigger view and are comfortable with the crop. The available controls can differ between apps.
