The New Yorker just posted a video I made about holographer Jason Sapan. His business, Holographic Studios, is the last remaining gallery/studio of it's kind in NYC. Jason is a fascinating guy. What I learned about holography was actually kind of stunning. I had no idea how powerful the resolution of holographic photography is. There is no focus involved. The laser acts like wet clay, and when it impacts on an object it takes an impression of the object, like a bas relief, and leaves a three dimensional image in the film (which to a light wave is a very thick sheet).
Well, watch the video, Jason does a far better job of explaining the process than I do. Also, holograms! Eat your heart out Jem!