If you are filming two people talking and you suddenly move your camera across the invisible line between them, what confusing thing happens to where the people appear on the screen to the viewer?

When filming two people talking, an imaginary boundary known as the 180-degree line, or axis of action, is established between them. This line dictates which side the camera should remain on to maintain consistent screen direction and spatial relationships for the viewer. If the camera suddenly moves across this invisible line during filming, the most confusing thing that happens is a complete reversal of screen direction for the characters. The person who was previously positioned on the left side of the screen will abruptly appear on the right side, and the person who was on the right will appear on the left. This sudden flip disorients the viewer, making it seem as though the characters have illogically swapped places or are now facing the wrong direction relative to each other, even if they have not moved within the filmed scene. The audience's established mental map of the scene's geography is broken, causing confusion about where each character is located in the space.