What is the "off-axis" caused by split-lens shooting?

You should say "off-axis". In the scene scheduling of film and television, the action direction of characters or the positional relationship between characters constitute an invisible axis. When changing the viewing angle (aircraft position), it is limited by the axis law. In the range of 180 degrees on one side of the axis where the total angle is located, no matter how to change the camera angle, the lenses with different perspectives will not cause the direction confusion on the screen after being connected. Observing the axis law and changing the perspective can ensure that the action route of the characters and the position relationship of the characters are always clear.

The axis generated by the direction of the role action is called the direction axis.

The axis produced by the positional relationship between characters is called the relationship axis.

"Off-axis" is also called "off-axis", that is, when the lens changes the angle of view, it exceeds the range boundary of one side of the axis 180 degrees. Deviation from the law of the axis will cause confusion in the direction of action on the screen or in the positional relationship between characters. In the scene scheduling of film and television, in order to highlight a certain key point and give full play to the dramatic effect of the plot, some shots need to be shot from the other side of the axis. The usual method:

1. Add a neutral lens on the axis between the "broken" lenses;

2. Change the original axis in the movement of the lens or the action of the character to form a new axis;

3. Insert an empty shot or a character in the other direction to make the transition.

Off-axis shooting and off-axis editing will cause visual confusion to the audience.

For example, the first shot is to shoot a person talking, and the next shot is to shoot the listener and the speaker in the same direction;

For another example, the first picture shows a car driving to the right, and then the second picture shows the car driving to the left.