daguerreotype: a photograph made by an early photographic process; the image was produced on a silver plate sensitized to iodine and developed in mercury vapor
photograph: a representation of a person or scene in the form of a print or transparent slide; recorded by a camera on light-sensitive material
geodesic: (mathematics) the shortest line between two points on a mathematically defined surface (as a straight line on a plane or an arc of a great circle on a sphere)