False start detection: These are blocks that are connected to the starting blocks in each lane. It is then connected to an apparatus next to the field, where the starter will start the race from. There is also a microphone running to the starters ear. The blocks react to pressure, therefor as soon as an athlete changes the pressure on the blocks, before the gun was fired, a beep will sound in the starters ear. This then leads to a false start or whatever the starter redeems right. The official reaction times are also coming from this machine. The reaction times are send to the results computer and the combined with the official results.

  1. Starters gun: On the gun is a transducer that are very sensitive to any vibration. The transducer is also plugged into the system as is all the other mentioned apparatus, in order to get a fair result for each race.

What happen in the electronic timing room?

  1. The camera gets set-up and connected to the track via an interface box. It is also connected to a computer.
  2. Interface box: To this box are also connected cables that run to the computer, from a port, to read the wind speed and to convey the time to the scoreboards. It also has a port for a remote control that the photo finish judge uses to manually open and close the photocells. This is extremely important when an athlete falls or stumbles over the line and goes under the infra-red beams of the photocells and therefor do not activate the cells automatically. Also when a long distance race is run we do not need the lap times as it will only use space unnecessary in the cameras memory. Then the cells are closed and only opened when the athletes complete the race. With sprints it is set to auto. The race will then be recorded automatically.

How does the camera work?

It is a very sophisticated instrument. Without getting to technical I will try to explain in short.

  1. The speed at which the lens opens and closes are set beforehand into the programme by the photo finish judge, according to the distance to be run and the age of the athletes. The light might also have an influence as in any camera. The speed is measured in frames per second. 250 frames (very slow and considered hand timing) to 2000 frames per second when Usain Bolt runs.
  2. The camera is focused on only 25mm black blocks on the finishing line – and that is the ONLY place it will and can take a picture!
  3. This picture is also taken differently from an ordinary camera. An ordinary camera or video camera takes pictures horizontally. The photo finish camera take photos vertically and then put the frames together to produce a picture.
  4. How does the camera know when to take the picture? This happens as soon as there is something or someone or preferably an athlete braking the beams of the photocells. As soon as the infrared beams get interfered with the camera’s lens will open and take a picture. Furthermore, the scoreboard(s), showing the time, also stop. This however, does not mean that the electronic timing has stopped!!! Only the photo finish judge operating the system can stop the clock after all athletes have crossed the finish line.
  5. As soon as the clock is stopped, the operator then saves the information to the computer. A screen will then open showing the athletes on the finishing line. The measuring of the time then starts for each athlete. It is noteworthy that ONLY the torsos are measured – no arms, hands, head, legs or feet.
  6. When the athletes finished – to the human eye – simulations, the camera can distinguish which one is the victor! The operator can blow the picture up by 600 times! At that stage we can see which pixel went over the line first to determine which athlete won the race.
  7. The time is also measure in 1000th of a second and then gets rounded down to 100th of a second. This means that two athletes finish simultaneous can get the same time, but the one that got 1000th of a second faster will get to win.

It is very important to note that everything happens automatically. The operator is nowhere involved in manipulating the photo or the time!


These days all the information are send between computers, printer, television broadcasting and internet via Wi-Fi or networks.

To sit in front of a television and watch meetings and results, all of the above must happen. Even on the Internet all results, with the photo-finish photo and reaction times of the athletes are available if the meeting director wish to create a website for the meeting.

I think we can now appreciate that the photo-finish judge is not just sitting around playing on the computer – it is extremely stressful and acquire a lot of concentration. You have to do this for 8-12hours non-stop.

For more information, go to: www.timetronics.be/athletics.html