The experience of viewing a daguerreotype is unlike that of viewing any other type of photograph. The image does not sit on the surface of the plate. After flipping from positive to negative as the viewing angle is adjusted, viewers experience an apparition in space, a mirage that arises once the eyes are properly focused. Of course when reproduced via other processes, this effect associated with viewing an original daguerreotype will no longer be apparent. Other processes that have a similar viewing experience are holograms on credit cards or Lippmann plates.