1. A method, comprising: performing a capturing operation including capturing a raw light field photograph of a space; performing a face-detection operation including detecting whether a face is present in the space; performing a locating operation including locating an eye portion of the face; performing a focusing operation including rendering, from the raw light field photograph, a focused image comprising a focused eye portion; performing an extracting operation including extracting an iris template from the eye portion of the focused image; performing an authenticating operation including determining whether the extracted iris template matches an authorized iris template; and performing a predetermined operation in response to a first result of the determining, and not performing the predetermined operation in response to a second result of the determining.