ABSTRACT
When images are captured on film or video, objects that are moving appear blurred, while static objects appear sharp. This is due to the fact that the camera is capturing samples of time, and the camera shutter is kept open for some of that time. The faster the object moves, the more distance it will cover while the shutter is open, and the less distinct the image. This motion blur makes for smoother motion and is a quality often lacking in computer-generated animation. After Effects creates the illusion of motion blur by calculating intermediate positions of a layer between frames of a render, then blending together these multiple copies of the layer. The Shutter Angle parameter controls the amount of time the motion blur samples are spread over, and therefore the length of the blur. Shutter Phase determines whether the intermediate frames start after the current time or before.
