system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why turning your phone sideways takes a wider angle shot. Isn't the camera the same size no matter what angle its on?
gpt
A camera has two main parts:

- A circular glass called a lens, which focuses light.
- A rectangular light catcher, called a sensor.

The first is a circle and so the angle does not change. The second is a rectangle. When you flip your phone sideways, you flip the rectangle sideways, too.