A photographer tested the concentration of several pairs of dogs as he captured their reactions to treat time in a series of shots. Christian Vieler, 47, of Waltrop, Germany, has been a professional dog photographer since 2016. He came up with the idea of snapping two dogs catching treats simultaneously. Here: Basset Hounds. (Photo by Vieler Photography/Caters News Agency)

This 1950s photo provided by the Estate of Vivian Maier and John Maloof Collection shows Maier in a self-portrait as she looks into a storefront wearing a hat in New York. New research about Maier shows the enigmatic Chicago nanny was obsessive about honing her skills as a photographer starting in 1950. (Photo by Vivian Maier/Estate of Vivian Maier and John Maloof Collection via AP Photo)

Women carry a portable shrine, a Mikoshi, through a street in Tokyo's Asakusa district during the Sanja festival, Japan, May 15, 2016. (Photo by Thomas Peter/Reuters)

A Highland Cow at sunset on the edge of the Marlborough Downs, Wiltshire, United Kingdom on October 18, 2020. (Photo by David White/PictureExclusive)

A Sotheby's employee poses with a “Return of the Jedi” promotional C-3PO Helmet 1983, estimated at £15,000-£25,000 created by George Lucas' visual effects company during a photocall at Sotheby's in London, Britain on December 6, 2019. (Photo by Thomas Mukoya/Reuters)

Lucy Blacker from Australia takes to the water at the 40 Foot for a Christmas Day Swim in Ireland on December 25, 2022. (Photo by Alan Betson/The Irish Times)

A couple take photographs alongside the National Monument on Calton Hill, Edinburgh on Wednesday January 5, 2022, ahead of First Minister Nicola Sturgeon's update to the Scottish Parliament on the Covid-19 situation as the Omicron variant sweeps across the country. (Photo by Jane Barlow/PA Images via Getty Images)

The Heavens opened as students from Wells Blue school year 13 pupils arrived at The Bishop's Palace in Wells, Somerset on June 30, 2022 for their end of year school prom. (Photo by Jason Bryant/Apex News)