Photography: How to shoot underwater lighting

Duncan Longden, photographer for our China feature, explains how he captured the underwater lighting of the Dujiangyan irrigation system.

By Duncan Longden
Published 5 Nov 2016, 13:00 GMT, Updated 7 Jul 2021, 17:31 BST
Dujiangyan irrigation system
Dujiangyan irrigation system.
Photograph by Duncan Longden

Shutter speed: 1/6 sec
Aperture: f7.1
ISO: 2000

The Dujiangyan irrigation system is the world's oldest, originally built around 256 BC by Li Bing and his team of labourers. Locals and visitors hang out on the historic bridges and enjoy the relief the breeze along the cool, fast-flowing river brings from the heat of the day. Restaurants, mostly serving fish, freshwater crab, shrimp and the occasional very large frog, line the river on either side.

Arriving around three o'clock, I scouted the area for my shot. I knew I wanted to use a long exposure, so a tripod was a must; I set up and settled in. Sundown was between six and seven, giving me a three-hour wait for the scene to develop — lots of time for people-watching. Many would come and lean on the rail staring motionless at the ferocious water churning below; they appeared hypnotised.

I was set up for long exposures, my Nikon D800e and Nikon 14-24mm F2.8 mounted firmly on my Vanguard Tripod. I had the ISO set to 100, but now I needed to adjust for this scene to my right, the one I'd been avidly viewing most of the afternoon. I upped the ISO to 2000, setting my aperture to F7.1 to gain enough depth of field and a shutter speed of 1/6 sec, slow enough to blur movement, but just fast enough to capture someone standing still, even just for a second. I watched, cable release in hand, as a lady stepped into the frame and looked along the river. I raised the mirror, counted to five to let any vibration settle and released the shutter. She stayed still while the people and river flowed around her. I'd got the shot.

Scenes like this are hard to meter. I don't use HDR, but that wouldn't have worked — it had to be a one-exposure deal. Using the spot meter on my camera I found a good average setting, made two tests, reading my histogram to adjust slightly. With film, we expose for the shadows and develop for the highlights. With digital, we expose for the highlights and process for the shadows, looking after the highlights. As the sunlight faded, the river began to glow blue, contrasting against the orange and red streetlights. I took the photograph I'd set up for, but now felt there was a more interesting story to be told.

See more of Duncan's photography and get more tips with our FREE digital-only Photography Magazine.

Published in the November 2016 issue of National Geographic Traveller (UK) Photography Magazine

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