1. An iris imaging system comprising: an acquisition subsystem comprising: a first light source for producing a first optical beam, and first optics having a first aperture, for directing the first optical beam through the first aperture to illuminate a subject's eye within a capture volume and further for receiving through the first aperture a retro-reflection of the first optical beam from the subject's eye to identify an approximate location of the subject; and an imaging subsystem comprising: a second light source for producing a second optical beam to illuminate an iris of the subject's eye, second optics having a second aperture spatially separated from the first aperture, so that the second aperture does not receive the retro-reflection of the first optical beam, the second optics for producing an image of the illuminated iris, and a camera for capturing the image of the illuminated iris with sufficient resolution for biometric identification.