Lord Mayor's balloon regatta, 2019The Guardian photographer Graeme Robertson rose early last Sunday to photograph nearly 50 hot air balloons that took flight across London, as part of the fifth Lord Mayors Hot Air Balloon regatta. Robertson, who was photographing them from the basket of a balloon himself, took off from Battersea Park just after 5am, as the sun came up. Once wed passed the City, I knew Id be able to turn back and shoot the balloons behind me, with the buildings