When Susan Sontag first proposed the idea of an "ecology of images" in On Photography, she meant it as an exhortation to be vigilant against the onslaught of images from advertising and television that she believed threatened our ability to truly see.

Today, beyond deep anxieties over a diminishing "attention economy," concern focuses on the environmental cost of storing and circulating the digital images that confront us with unprecedented speed.

Against the disposable rapidity demanded by digital media, Peter Szendy emphasizes the labor and time required to produce and properly view images. His inquisitive mind and sparkling, associative style of writing take us from the animal kingdom to the scientific history of the shadow, the theorems of Pliny to Nabokov's butterflies, the first use of slo-mo in film and the first aerial photograph.