Photo finish: the tech that times the 100 meter sprint at the Olympic Games

The 100-meter sprint is one of the most prestigious events at the Olympic Games – and one of the fastest. The world records for the event stand at 9.63 seconds for men (set by Usain Bolt in 2012) and 10.60 seconds for women (set by Elaine Thompson-Herah in 2021). With 0.01 of a second making all the difference, timing is crucial, and TechRadar spoke to CEO of Olympic Timing at Omega Alain Zobrist to find out exactly how it's done.

Omega has been the official timekeeper of the Olympic Games since 1932, when a single watchmaker was sent all the way from Switzerland to Los Angeles with 30 chronographs in a suitcase.

Things have changed a little since then, Zobrist explains, and 530 timekeepers from Omega travelled to Japan for this year's event, along with 400 tons of equipment, to provide results for athletes participating in all sports.

On your marks...

For the 100 meters specifically, there are three groups of machines and equipment necessary to get the timing absolutely right: one at the start, one at the finish, and one covering everything in between.

"It begins with the start gun, starting blocks, and a full start system," Zobrist says. "So the starter would give the start command and push the trigger to start, and as soon as [they do] that, the clock starts to count."

Once the race has begun, the first measurement is taken using sensors in the backs of the starting blocks. "We're measuring the horizontal pressure of the athletes in the blocks 2,000 times per second, so it gives us a very accurate understanding of the reaction times of athletes," says Zobrist.

We're using motion sensors and positioning systems on the athletes to measure their position, their exact speed, their acceleration and deceleration

Alain Zobrist

During the race, the timekeepers also measure a lot of other essential information, such as weather conditions, in accordance with the rules of World Athletics. For example, it there's too much wind, a world record may not be recognized. The athletes themselves are tracked as well, giving extra insight into their performance.

"For the very first time here in Tokyo, we're also using motion sensors and positioning systems on the athletes to measure their position, their exact speed, their acceleration and deceleration," Zobrist explains. "And it allows us to tell at the end of the race where an athlete has gained or lost time."

Alain Zobrist, CEO of Olympic Timing — Alain Zobrist travelled to Japan with 530 timekeepers to cover all the events in this year's Olympic Games (Image credit: Omega)

At the finish line, cells installed along each side of the finish line stop the running time on TV, and on scoreboards in the stadium. That provides an unofficial time for the race, but the official times are measured with Omega's photo finish cameras.

"We have three of them installed on the finish line," says Zobrist. "The main camera and the back camera on one side of the finish line, and an infield camera on the other side of the finish line, so we can capture the entire action as it happens. So if two athletes cross next to each other, we will always know which one crosses the line first."

Picture perfect

Omega introduced its first cameras back in 1948. These were black and white film cameras, and the film had to be developed in a darkroom for between 30 and 45 minutes before the results could be checked.

"Today, we're using a photo finish camera called Myria, which Omega introduced in 2014, for the first time," Zobrist says. "It takes 10,000 picture of the first 8mm of the finish line, and it assembles those images 10,000 per second, so it gives us a very good understanding of what happens on that finish line, and we'll always be able to tell very precisely who crossed the line first, and what their time was."

[The camera] takes 10,000 picture of the first 8mm of the finish line, and it assembles those images 10,000 per second

Alain Zobrist

Once the timekeepers have evaluated that time, together with the judges, the post-race management of the results begins.

"All those results are formatted and provided in real time to a variety of stakeholders – mainly broadcasters, so they can show special graphics on TV to explain the action as it happens, to scoreboards in the stadium, to commentator information systems, and to multiple websites to inform everyone watching."

The Tokyo 2020 Olympics are in their final days, and the closing ceremony will take place on Sunday August 8, but there are still lots of events still to come. Check out the full schedule, and make sure you don't miss a moment.