A method and apparatus for making holograms includes a technique for
exposing a film substrate or other light-sensitive medium to consecutive
two dimensional images, together representative of a physical
three-dimensional system, to generate a three dimensional hologram of the
physical system. Low beam ratios are employed to superimpose multiple
(20-300) images on the substrate. Each image is relatively weak, but the
combination of the series of weak images ultimately appears as a single
clearly defined hologram.