Order no. 421.PSK
The current enthusiasm for 3D effects easily overlooks the fact that the basics were researched 180 years ago by the Englishman Charles Wheatstone:
We see three-dimensionally because the eyes see the world from different angles. As proof, he constructed a pseudoscope in which the images for the two eyes are swapped, in addition to the stereoscope that is still widely used today.
This has astonishing consequences: The spatial arrangement turns upside down, the front becomes the back and vice versa, a positive relief becomes a negative… You have to see it yourself to believe it.