Broken glass, and broken windows in particular, are a notable byway in photography’s history. Brett Weston made one of the most striking examples in San Francisco in 1937. Weston was not recording evidence of a crime, or even particularly making a sociological comment. He was describing an abstraction with his camera, the calligraphic presence of a jagged black hole surrounded by a gray remnant of glass. What has been broken away dominates the picture. We see an outline like a map of a fictional island. There’s more dark to see here than glass, and the darkness is deep and mysterious, a mouth agape in an unending scream. About this picture, John Szarkowski, the influential curator at the Museum of Modern Art, wrote that the black shape “is not a void but a presence; the periphery of the picture is background.” In the middle, in that darkness, is where Weston’s self-portrait would be, if the window were intact.