The important thing is to mount something light, and do not disturb the movement move; use a right angle to shoot without disturbing the person's vision. And think of a way to stick the cell phone there. It may be with Velcro, double-sided tape, or a fixed cell phone. There are those who use a document camera, with fixed focus, but a webcam with an adjustable focus may be enough:
- You shoot the person's finger and the interaction on the screen.
- One can pick up the cell phone and move with it, and maybe even walk away, until the camera cable runs out.
- Because the camera is attached to the computer, you can keep track of what the person is doing.
- If you have Morae, you can use it to sync the two cameras. ...