user6509: What is the most accurate proximity sensor for a ping pong ball? I will be using this to calculate 3D positioning of a ping pong ball in flight. I only need to detect the ball within 0-5 feet (basically on one side of ping pong table). 

user19892: I've had some good luck with using the Pixy camera system. 
http://www.cmucam.org/projects/cmucam5/wiki
You get a maximum of 50 FPS and can detect and locate different objects based on hue. The library function getBlocks() returns the X and Y center location of each of the objects the camera detects. You teach the camera what hues to recognize as blocks, and adjust the detection thresholds. I use mine in monochrome infrared light by adding a visible filter and lens kit from http://irlock.com/

6509: <p>What is the most accurate proximity sensor for a ping pong ball? I will be using this to calculate 3D positioning of a ping pong ball in flight. I only need to detect the ball within 0-5 feet (basically on one side of ping pong table). </p>
 19892: <p>I've had some good luck with using the Pixy camera system. </p>

<p><a href="http://www.cmucam.org/projects/cmucam5/wiki" rel="nofollow">http://www.cmucam.org/projects/cmucam5/wiki</a></p>

<p>You get a maximum of 50 FPS and can detect and locate different objects based on hue. The library function getBlocks() returns the X and Y center location of each of the objects the camera detects. You teach the camera what hues to recognize as blocks, and adjust the detection thresholds. I use mine in monochrome infrared light by adding a visible filter and lens kit from <a href="http://irlock.com/" rel="nofollow">http://irlock.com/</a></p>
