So, how did they do it? It may seem a bit amazing, but the process was fairly simple:
1. Pick a good scene. This one has lots of depth, lots for the camera to see.
2. Inside the camera the image is upside down. There are two lenses to take both left and right side of the picture. When everything is just right, you take the picture.
3. Your final image is four inches tall and ten inches wide. Notice that some of the image overlaps in the middle. Also notice that when you turn it right side up the two sides are now inverted. It is actually possible to see the 3D if you cross your eyes while looking at the image until a third image appears in the middle.
4. In the restored image clouds have been added back in, damage has been repaired and color has been added back. Note that portions of the image in the center and far right that will not appear in the final card have been left.
5. Finally our finished card. The left and right hand sides have been put back to their correct position and trimmed of any remaining damage. The image is fitted to the frame and captions are added. Of course the original would have been in black and white.