Camera Rig Follow Target From Angle Only When character Reaches Edge of Screen

I currently have a camera rig set up with a -45 degree, pitch, at 30m away.
PROBLEM: Camera always follows the sphere around when sphere is moved.
EXPECTED RESULT: Sphere rolls around until it is near the edge of the frame and then the camera moves with the sphere, but only when the sphere is near the edges of the camera frame.

Any help is much appreciated! Javascript coder getting my feet wet with Lumberyard. Thanks!