Image Focus

It’s March 2025 and a human river is snaking its way down the Rue de Rivoli, Paris. The brightly coloured running bibs and t-shirts of the competitors in the Semi-Marathon de Paris blend into a rainbow of colour as they move past Bertrand Bernager’s camera.

Long exposures can be used on any subject, so why did Bertrand apply the technique to marathon runners? “To me, it’s the contrast of the human movement in the unmoving city,” he explains, “the way the architecture offsets the flow, like the world is on fast-forward.”

“The first time I tried it, I was out at the marathon shooting in a regular way, freezing the movement of the runners, but it wasn’t satisfying to me,” Bertrand continues. “I realised I had a tripod and an ND filter, so I thought, why not try something different. The result was something that’s completely natural but totally unseen until you put it on camera. It’s always different, always surprising. It fascinates me.”

Deliberately slowing the shutter is a thrilling moment of discovery for many photographers, but as Bertrand explains, it’s simple to achieve. “This image is a single 20sec exposure,” he says. “Working in Manual, I set a very low ISO of 50, while closing the aperture to f/11, but the real key is adding a strong neutral density filter to the lens, which cuts out a lot of light. I used a 10-stop filter. Without it, the speed would be 1/50sec, showing no blur at all.”

“Obviously you need to shoot from a tripod, because here we only want the runners to blur, not the buildings” he continues. “And so long as the camera stays still, so will they. I try to use speeds between 5secs and 20secs, depending on the pace of the runners. Any shorter and they won’t blur, too much longer and they’ll disappear.”

“The use of a remote commander is also essential. With the many connectivity options available on Sony cameras, I use either the RMT-P1BT Bluetooth remote or the Creators' App to wirelessly control my camera without generating vibrations.”

Shooting position and framing are also important, he says. “I like to be a bit above the action, so I have my tripod at full height, while the longer focal lengths of a telephoto lens like the FE 70-200mm f/2.8 GM OSS II give a tighter frame that the runners move through quicker. They also compress the scene, making the background architecture more prominent.”

And while the Sony Alpha 1 Bertrand used is respected for its high-speed sporting credentials, here it’s the camera’s resolution wide dynamic range he relies on. “Shooting in Raw, the Alpha 1 records so much information that I can easily adjust highlight and shadow exposure when I need to,” he explains, “and that’s vital if the light changes during an image, which it often does!”

“What I really love is the waiting,” Bertrand finishes. “You put in the ingredients, then 20 seconds later the screen shows you something special. I want to make a series of similar images, covering all major marathons around the world, like London, Berlin, New York and Tokyo. The races all have a different feeling, and so each new exposure will, too.”