1. A method for operating an autofocus system for focusing an image on an electronic imager, comprising: a. providing an adjustable lens system defining an optical path for scene light and having at least one movable lens to focus an image of the scene onto the electronic imager; b. causing a first portion of the scene light to be obscured so that the electronic imager captures a first autofocus image and causing a second different portion of the scene light to be obscured so that the electronic imager captures a second autofocus image wherein portions of the first and second autofocus images are offset; and c. moving the movable lens in response to the offset to a position so that an image to be captured will be in focus.