German photographer Stephan Zirwes started capturing public swimming pools from the air in 2015. ‘They are very structured,’ he says. ‘The lanes, the diving platforms – I love the geometrical forms.’ But he was not just captivated by the aesthetic qualities of the pools – it was also about what they represent. ‘In Germany, nearly every small town has a pool. They’re a part of the social-cultural life, open for all social classes.’ His series has been shortlisted for the 2019 Sony world photography awards (announced on 17 April). They were all shot by drone, an essential gadget for Zirwes, who started to specialise in aerial photography 15 years ago. ‘It was my way to show the world in a new way. With the popularisation of drones, aerial photography has become a new genre’

