Marco Koch (bottom), the men’s 200-meter breaststroke world champion in 2015, during a nighttime training session at Darmstadt’s Nordbad, some 45 kms (28 mls) south of Frankfurt, July 14, just a few days before flying to Rio to take part in the Olympics. The scene is lit by floodlight and two remotely triggered studio flashlights positioned diagonally left and right.