holograms are made with light flashed onto a plate or screen, almost like how photos are made. to make a hologram instead of a photograph, some of the light, called a "reference beam," has to go directly to the screen. the light has to be a laser because lasers are more accurate and have a wavelength that does not change the way the wavelengths of light from other sources does, like light from lightbulbs. to stop other light from ruining the hologram, holograms are usually taken in the dark. because even the tiniest vibration can stop the hologram from forming properly, the tables upon which that the holographer places the equipment may be built with shocks or inflated chambers to stop vibrations from the floor.