L E D - T r a c k i n g

The LED tracking ball is a very good alternative to conventional tracking balls and is pretty easy to make.

  1. Start off by cutting the top of a ping-pong ball ("bad quality" ping-pong balls are better, the plastic is more rigid)
  2. Get a fluoro red spray can and paint it - It's better to work in layers leaving a few minutes for each one to dry
  3. Get a needle and burn it with a lighter for a few seconds, then make the holes on the back to fit the switch and the LED on the front
  4. Be careful soldering the wire to the switch so you don't burn the ping-pong ball
  5. Add some silicone in there leaving a gap to fit the battery

The idea was to make a tracking marker where you would have 2 options

  1. If it is a wide shot you can track the whole ball (like conventional markers)
  2. In a medium or close shot though, you can track the green LED having the fluoro red in the background which makes it easier for the tracking software to work out the contrast provided.

Another advantage is that you can use it at night or with poorly lit scenes. The LED still illuminates an area of 1-2cm around it.