This is the amazing moment a heroic hippo saved a gnu from certain death. After being bitten by a crocodile, the large antelope is seen being dragged slowly under the water. But in a miraculous turn of events, a nearby hippo is seen making its way across the water to help the animal in its hour of need. Photo: One of the biggest hippos protects the gnu as it makes its way back to the shoreline, guarding it from any further attacks. (Photo by Vadim Onishchenko/Caters News)

Joseph Szabo was a frustrated high-school teacher in need of inspiration – so he started photographing his students, and captured all the angst and excitement of being caught between childhood and adulthood. Here: “Priscilla”, 1969. (Photo by Joseph Szabo/Courtesy of Michael Hoppen Gallery/The Guardian)

A participant holds his dog as colored powder is thrown into the air during the Color Run in Lausanne, Switzerland, 12 September 2015. The international 5km running event is inspired by the Hindu Holi spring festival of colors. (Photo by Valentin Flauraud/EPA)

A leopard runs to at people as they run for cover in Katmandu, Nepal, on April 10, 2013. According to reports, 15 people were injured including three policemen and two officials from the Department of Forest. The leopard was later killed with the help of Nepalese policemen and local media. (Photo by Niranjan Shrestha/Associated Press)

ATTENTION: VISUAL COVERAGE OF SCENES OF INJURY AND DEATH

Girls take part in the traditional seasonal Christmas run along the streets of Vilnius, Lithuania, Sunday, December 17, 2017. The festive run attracts many hundreds of people to the capital dressed as Santa Clause to take part in the sporting event. (Photo by Mindaugas Kulbis/AP Photo)

At the end of a six-year relationship, photographer Laura Stevens needed to find a creative, external outlet for all the complicated feelings she was processing internally. “Another November” is the end product, a photo series that aims to mirror those agonizing emotions that Stevens felt at the time of the breakup – and the subsequent healing process. Here: “Jessica” is photographed at her Paris home in this scene staged by photographer Laura Stevens. (Photo by Laura Stevens)

Light painting photographer Trevor Williams, also known as TDUB303, is a present day light painting pioneer. He creates some of his light painting imagery alone and also works with the group Fiz-iks, which he founded. Trevor is from Canada, he has lived in Japan since 2002 which is where he creates the majority of his work. His light painting images are produced with special attention to location, Trevor says, ““If you want to take an epic picture you need to go to an epic location.”