The invention comprises a method for configuring an imaging apparatus having an image sensor and an optical assembly. The method modifies a first imaging configuration of the imaging apparatus to achieve a second imaging configuration of said imaging apparatus, by interposing a refractive optical element between an image-side surface of the optical assembly and an imaging surface. In another embodiment, the method modifies a first imaging configuration of the imaging apparatus to achieve a second imaging configuration of said imaging apparatus by removing the refractive optical element from between an image-side surface of the optical assembly and an imaging surface. The invention additionally includes an imaging apparatus configured for switching from a first imaging configuration to a second imaging configuration. At least one of the first imaging configuration and the second imaging configuration may be configured for iris imaging.