However, new three-dimensional images have now been constructed using videos of historical motion-pictures. This technique (“stereo extractions,” as developed by the author) has resulted in a unique set of 70 stereographs of these lighter-than-air passenger liners, including one of airship pioneer and -commander dr. Hugo Eckener and one with journalist Grace Drummond-Hay during the world tour of the Graf Zeppelin in 1929.
The stereo images in "Zeppelins in 3d" are for parallax-viewing (cross-eyed, as explained in the introduction of the book; there is no need for a stereoscope or special glasses) and provide an opportunity to re-live the airship era in 3D, with impressions that up so far were only available in 2D.