Couples take part in the “Love and Challenge Marathon” in Hanoi, Vietnam, 16 August 2015. Fifty couples, who are going to get married, participated in the event which is held the fifth time. This year, the winners of the marathon received a honeymoon trip to Malaysia. (Photo by Luong Thai Linh/EPA)

The Virgin of El Rocio is carried by pilgrims during a procession around the shrine of El Rocio in Almonte, southern Spain, May 25, 2015. Every spring hundreds of thousands of devotees converge at a shrine to pay homage to the Virgin del Rocio during an annual pilgrimage which combines religious fervour and festive colour. (Photo by Marcelo del Pozo/Reuters)

Sеxy woman in lace eye cover and red lips with young lover, foreplay in hotel room. (Photo by sakkmesterke/Getty Images)

These images have been created using a colour scanning electron microscope (SEM) by the award-winning Eye of Science, comprised of snapper Oliver Meckes and biologist Nicole Ottawa. For a decade the pair, based in Reutlingen in the south of Germany, worked with an old SEM they saved from the scrapheap, but for the last five years they have used a £250,000 FEI Quanta Series Field Emission SEM. Oliver said: “Flowers are beautiful in 'normal' view, but when you look closer, some parts get very bizarre and unexpected structures appear – flowers within flowers, worlds within worlds”. Photo: The floret of a Chamomile flower up close and personal. (Photo by Oliver Meckes/Barcroft Media)

Elementary school children play outside their classrooms as mount Sinabung volcano spews thick volcanic ash in the background on February 10, 2017 in Karo, Indonesia. Mount Sinabung is one of the most active volcanoes in Indonesia and last erupted in May 2016, killing seven people. (Photo by Albert Damanik/Barcroft Images)

Cyclists compete during the UCI BMX World Championships Elite Women's Moto Race on May 29, 2016 in Medellin, Antioquia department, Colombia. (Photo by Raul Arboleda/AFP Photo)

“Woman with Umbrella in Rain” by Raimund von Stillfried. Artist: Kusakabe Kimbei (Japanese, 1841–1934), 1870s. Commercial photography studios in Meiji-era Japan were renowned for the subtlety and refinement of their coloring techniques. This hand-tinted image of a young woman caught in a heavy rainstorm achieved its naturalistic effect by knitting together multiple strands of artifice: the greenery in the foreground was a studio prop; the flaps of the kimono were suspended by thin wires to create the impression of a strong wind; and long, diagonal marks were made on the negative to suggest streaks of rain. (Photo courtesy of The Metropolitan Museum of Art)

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)