Making Holograms


As an undergrad, I spent many hours in the basement of Brown University’s 100-year-old Ladd Observatory making holograms: 3d pictures that look different from every angle. That basement was a bit spooky, but possessed two key useful ingredients for the amateur holographer: it was very dark, and very still.

We used low power Helium-Neon lasers and red-sensitive film, so even the dim lights typically used in photo dark rooms were forbidden. Long exposure times meant that even tiny vibrations could spoil the result. This venerable structure had a stable foundation, and no HVAC system or other mechanical equipment in use.

Creating a hologram involves splitting a laser beam to illuminate an object and a plate of film at the same time. We used mirrors and lenses and photographic plates, all secured to an optical table with hot glue. It was a low tech approach, but good for learning the underlying optical principles.

The field of Holography has come a long way in 20 years. In fact, there’s a company called Zebra Imaging that is able to create holograms from a digital 3d model. I thought this was very cool, and ordered a sample hologram that shows four different views of a SketchUp model. The video below shows how the image changes with a simple rotation.


Joshua Cohen is a Principal at Fat Pencil Studio