Models pose backstage at the Celia Kritharioti Spring/Summer 2012 fashion show at One Mayfair on March 20, 2012 in London, England. (Photo by Ian Gavan/Getty Images For Celia Kritharioti)

Model Alessandra Ambrosio (L) and Adriana Lima walk the runway during the 2011 Victoria's Secret Fashion Show at the Lexington Avenue Armory on November 9, 2011 in New York City. (Photo by Jamie McCarthy/Getty Images)

A model poses backstage at the White Carpet Blaque Runway fashion fundraiser at the Causey Contemporary Art Gallery on January 13, 2012 in New York City. (Photo by Jason Kempin/Getty Images)

Photographer Tyler Shields had become comfortable, a feeling he found “terrible” as an artist. He wanted to do something challenging, something that pushed the human boundaries. So he spent a year documenting heights, fear, energy and falling – a series he calls “Suspense”. Photo: “Balloon”. (Photo by Tyler Shields)

“They’ve been obsessing me for years. I searched and found them in Benares, on the banks of the river Gange (India). They arrive here to get rid of everything and to wait for death. This existence can last for years, sometimes decades, almost a life. Opposite to mine, well organised and filled as a human life can be, to try in vain to push the limits of its end”. – Denis Rouvre. (Photo by Denis Rouvre)

The Vietnam Slide Project was created by photo editor Kendra Rennick, who began collecting photo slides after a close friend lost her father, a Vietnam veteran. Her friend found a box of slides that her father had taken while in Vietnam and from there Rennick has continued to collect photographs that Vietnam veterans took during their tours of duty. Here: A photo taken from the collection of D.Thornton, who served in the First Air Cavalry division of the United States Army. (Photo by D.Thornton/The Vietnam Slide Project)