1. A method of varying focus in a scene, comprising: a) obtaining a dataset of photographs of said scene, each of said dataset of photographs created under separate focus conditions within a range of focus conditions; b) performing an approximation using said dataset of photographs that is capable of representing a spectrum of photographs of said scene, each of said spectrum of photographs having focus conditions within said range of focus conditions; and c) recording a plurality of values associated with said approximation, said plurality of values capable of generating each of said spectrum of photographs.