When ever taking of first shot completed, line of action will be established in view of the viewer. Line of action is the 1800 imaginary line in front of the camera where the action is going on. Once the line of action is established, camera should not be placed on the other side of the line of action. In the same scene, remaining shots should be taken from the sane side of Line of Action from which side first shot was taken. Crossing the line changes the viewer's perspective and there will be confusion like changing positions and reversing of actions. Crossing the line is also called as reverse cut. If it is essential to show the action from other side after establishing of 1800 line, camera should travel to other side while taking shot only. Then view point of the viewer also changes. From this shot onwards, remaining shots should be taken from that side only.        

Ex: According to the following image, view is like that the object is moving from right to left. If shoots next shot from other side of the line of action, view of the object movement will be from left to right. Due to this, object movement is suddenly reversed in the second shot which has been done immediately after first shot.