The role of red dot in blue screen shooting

The red dot is used to help locate the lens, because when shooting the blue screen lens, we have to shoot the real scene again, and then use the computer to synthesize the contents of the two lenses. These points are used to represent the camera's actions, so that the camera's actions are exactly the same when shooting twice, otherwise the synthesis will become a big problem.

In addition, the red dot on the actor's clothes is to capture the action. Sometimes it is necessary to replace a specific actor with a computer character, which is necessary.