most modern day holograms use a laser as its light source. in this type of hologram, a laser is shone onto a scene that is then reflected onto a recording apparatus. in addition, part of the laser must shine directly onto a specific area of the display to act as a reference beam. the purpose of the reference beam is to provide the recording device with information such as background light, picture angle, and beam profile. the image is then processed to compensate for any variation in picture fidelity, and then sent to the display.