Scherzer and Ekroll [2012] analyse motion in terms of occlusion. They consider the perception of motion in terms of the occlusion of the background, by a moving object, or occlusion of the moving object by the something in the foreground. Their experiment concludes that motion is perceived as smoother if the spatial gaps between key positions is occluded, or if the gaps themselves are reduced in size. Smith [2010] discusses how the motion we perceive in film is known as apparent motion, because of its origins in static images rather than actual motion, further classifying this motion into long-range and short-range. Long-range motion, such as beta movement, when two objects are alternately shown at different locations ten times a second, giving the perception of fluid movement of a single object. This type of motion requires us to have a knowledge of the real world movement, as well as there being a correspondence between the objects in the sequence. Short-range movement occurs when the displayed images are shown rapidly (greater than 13Hz) show a slight difference in the objects position. This type of motion does not require an understanding of the motion as it stimulates the same system in the brain used to detect real world motion. In cinema most motion is perceived as being short-range motion. This is because film frames are too complex and the frame rate is too high to properly perceive what is happening in terms of long-range motion