How do you print those 3-D images which materialize alongside the goal in televised international football matches? We also see images printed on the grass of some sports fields, a technique more favored at televised rugby games. We rugger buggers always loved getting mud and dirt all over ourselves, so paint just adds another dimension. Here we see a large box advertising BT at a recent World Cup qualifier game featuring multiple goals from Harry Kane:

From the second photo, with the camera at a different elevation, you can see that the apparent BT box is actually just a flat mat, cunningly printed, lying there just over the goal line.

Now, the temptation to view this advertising method as some sort of high-tech magic should be resisted. It’s just anamorphic perspective, as used in 1533 by Hans Holbein The Younger in his painting The Ambassadors to be found in The National Gallery in London.

At the bottom observe the heavily distorted skull, which if viewed from the “correct” viewpoint looks like this:

Advertisers know that when the football game is televised the vast majority of the action will be followed by cameras in the stands, and as these are all at the same height from the pitch the distortion needed to make the flat image appear to be standing up is a known amount. There are also cameras placed low-down in order to show corner kicks and other goal-mouth detail. Only when these lower-level cameras are in operation will the 3-D object be seen to collapse into flat reality. Nicest, which I wasn’t able to photograph, is when a player walks across the printed mat, making it appear as if he’s magically walking through a hoarding.

Anamorphosis goes even further back. Alcamenes and Phidias 5th century BC sculptors allegedly competed to create an image of Minerva. Alcamenes’ sculpture was seen as beautiful, while Phidias’ was out of proportion. However once they had both been mounted on tall pillars, it was seen that the different viewpoint reversed the judgement.

The process is analogous to the Ames Room effect, where, when viewed through a peephole the room appears in perfect perspective, while it in fact consists of irregular trapezoids. Such rooms are used in film making, where they can be used to distort proportions making Alice really large or absolutely tiny.