Pretty Girls, Ugly Faces is a photo fad in which girls take pictures of themselves while posing in an unflattering manner, making a silly face or performing a physically strenuous activity.

David Guttenfelder was born in Iowa and graduated from the University of Iowa with a Bachelor of Arts in cultural anthropology. He has worked for the AP since 1994 based in Kenya, the Ivory Coast, India and Japan. He is currently AP’s chief Asia photographer and his feature work has been used prominently in editorial publications throughout the world including Time and National Geographic. Photo: U.S. soldiers from the 2nd Battalion, 12th Infantry Regiment, 4th Brigade Combat Team, fire mortars at known enemy firing positions from a base in the Pech River Valley in Afghanistan's Kunar province, Saturday, October 24, 2009. (Photo by David Guttenfelder/AP Photo)

141 boxers’ by Danish visual artist and photographer Nicolai Howalt is a series of diptychs portraying boxers before and after their fight. Ranging from young boys to women, the collection of images delineates not only the brutal aftermath of a match but the more subtle changes in the subject’s physiology due to adrenaline, struggle, and the complex emotions that come with victory and loss.

French artist Julien Breton aka Kaalam started calligraphy in 2001 by copying Arabic calligraphers. Self-taught, he began to incorporate long exposure photography to create incredible light paintings around the world. All of the images in this gallery were created in-camera, meaning there is no Photoshop trickery or post-production manipulation involved in creating these works of art.

View of colourful rock formations at the Zhangye Danxia Landform Geological Park in Gansu Province, China. The Zhangye Danxia Landform Geological Park is 40km from Zhangye city. The park spans more than 400 square kilometers in Gansu. The unusual terrain is the result of red sandstone and mineral deposits carved over the years by natural forces. (Photo by ImagineChina/The Grosby Group)

A model poses in front of the new Lamborghini Huracan during the media day of the 84th Geneva International Motor Show, Switzerland, Tuesday, March 4, 2014. (Photo by Laurent Cipriani/AP Photo)

A woman sits with a Great Dane during the first day of the Crufts dog show in Birmingham, central England March 6, 2014. (Photo by Darren Staples/Reuters)

In this photo taken Tuesday, October 14, 2014, skulls and bones are stacked at the Catacombs in Paris, France. The subterranean tunnels, stretching 2 kilometers (1.24 miles), cradle the bones of some 6 million Parisians from centuries past and once gave refuge to smugglers. The site used to close at 5 p.m., but is now staying open until 8 p.m. The change is mainly aimed at allowing more people to visit and reducing long lines, since it can only hold a limited number of people at a time and visits can't be reserved in advance. (Photo by Francois Mori/AP Photo)