Professor Steve Benton was a pioneer in the field of holography, the founding head of the MIT Media Lab Spatial Imaging Group, and the inventor of the rainbow hologram found on most credit cards. Here is his definition of what a hologram is:
"Holography has come to take on two meanings in our culture. Firstly, it means wavefront reconstruction by interference and diffraction/reflection. More widely, it has come to mean the ultimate 3D imaging method of the future, and it stands as an optimistic hope for the progress of our science and technology relating to everyday life." - The Art and Science of Holography
Our 3D Hologram Printer meets both of these definitions!
The LitiHolo 3D Hologram Printer makes holograms by capturing the interference pattern formed by two laser beams (object beam and reference beam) onto hologram film. The 3D image is reconstructed by light hitting the captured pattern and diffracting light back into the original object beam direction, reconstructing the original wavefront of the captured object. This is the same fundamental concept that won the Nobel Prize in Physics 1971 for the discovery of holography, awarded to Dennis Gabor.
Many other things are often called "holograms", but are in fact lenticular displays (lens sheet), simple stereoscopic 3D (headsets and glasses), or Pepper's ghost effects (200-year-old optical illusion by simple reflection). "Lightfield" is a relatively new term to describe some 3D displays, and while holograms can be considered a subset of lightfield displays, very few lightfield displays are currently holograms.