A camera system may be used to capture iris images of targeted people who may be unaware of being targeted and hence their movement may not be constrained in any way. Iris images may be used for identification and/or tracking of people. In one illustrative embodiment, a camera system may include a focus camera and an iris camera, where the focus camera is sensitive to ambient light or some spectrum thereof, and the iris camera is sensitive to infrared or some other wavelength light. The focus camera and the iris camera may share an optical lens, and the focus camera may be used to auto-focus the lens on a focus target. A beam splitter or other optical element may be used to direct light of some wavelengths to the focus camera for auto-focusing the lens, and other wavelengths to the iris camera for image capture of the iris images.