“Blitz” is a stirring journey across World War II England through the eyes of a young boy named George (Elliott Heffernan) as he tries to reunite with his mother, Rita (Saoirse Ronan), at their East London home. In framing Steve McQueen’s historical depiction of Germany’s eight-month-long bombing campaign, cinematographer Yorick Le Saux beautifully interwove George’s emotional arc with the catastrophic enormity of war. “There was a lot to see around George, so we had to find the balance between him and the world around him,” Le Saux says. “We often placed the camera at different levels with the idea that this child is watching the adult world as he’s going through all these events. We wanted the sensation that it gets more difficult for him with each step.” One perilous scene occurs when George and a group of Londoners are trapped inside a subway tunnel that’s taking on water. The complex sequence was filmed on a soundstage that bridged a collaborative effort among practical visual effects, special effects and the cinematographer. Le Saux embraced the low-light sensitivity of a digital camera and light sources to illuminate the looming intensity of the moment — one that sees George transform from a scared boy into a life-saving hero.