Peter Turnley had considered neither photography nor Paris until he blew out his knee playing high school football. Called “French Kiss: A Love Letter to Paris,” the project is the grand-opening exhibition at Leica Gallery San Francisco, a camera store/photo venue that opened in August, on the edge of Union Square. The gallery, which runs the length of the store, will showcase works of the famous Leica shooters, which includes just about everybody who made a war picture in the 20th century. At the other end it is life at its best, Turnley, 59, says in a phone interview from his apartment on the Upper West Side of Manhattan. Since his own particular corner is in the Old World Fourth Arrondissement, between the Louvre and the Bastille, he doesn’t have to go far. There is nowhere in the world,” he says, “where one can see as many ubiquitous scenes of tenderness, affection, romance, and specifically of people kissing as in the streets, riverbanks, cafes and bridges of Paris.