Einstein Hollow face Illusion

The mask is 43cm high and 31cm wide. The very bottom of the sheet has been bent through 90 degrees, so the mask will stand up by itself. Grand Illusions original, Unused in original box.

This is a very powerful optical illusion. Place the mask upright, ideally with some back illumination – you can either stand the mask on a window ledge, or place a small light behind it. View the mask from the concave side, in other words with the mask pointing away from you. Even though you are viewing a face that is concave, the face will appear convex. As you move from left to right, the whole face will appear to swivel and follow you. It also works if you move up and down. In fact, keen observers will spot that the face does not just follow you, it actually moves more than you would expect. So that when you look straight on at the face, it seems to be looking directly at you; move to your right, and the face appears to turn so much that you start to see the face partly in profile. Seee Q.I program below.

https://www.youtube.com/watch?v=ORoTCBrCKIQ

https://www.grand-illusions.com/products/the-hollow-face-illusion