"Power" is a concept that conjures up different ideas for different people. There's the power of nature or the power of money; or the drive for power at the root of the human psyche — and how it can cause war and discrimination. Or, more literally, how we humans power our existence on the planet.
But how do you photograph it? That was the challenge for the Prix Pictet prize this year — a "global award in photography and sustainability," now in its fourth cycle. Previous themes have been "water," "earth" and "growth," drawing submissions from some of the world's most renowned photographers.
This year, that included stark black-and-white landscapes of clear-cutting in the American West; a study of the places where powerful Arab women work and live; scenes at Guantanamo; and a series called Fukushima: The Irresistible Power of Nature.
French photographer Luc Delahaye took the grand prize for his wide-ranging portfolio of dramatic scenes from around the world over the past few years: a mass grave in Bosnia; an epic shot of the aftermath of India's post-earthquake wreckage in 2004; and media madness at an OPEC conference.
The selection of images below represents the other finalists. You can see entire portfolios on the Prix Pictet site. And you can leave your comments here; what's your vision of "power"?