Windows

Imagine three frames, each on a wall, with essentially the same view of a landscape through them. The first is a window in a house, the second is a painting, and the third is a window on a theatrical stage.

In the case of the real window, the world seen through the window is in fact three-dimensional, and one can assume that clues in this window to what lies beyond the line of sight of the person inside will be largely confirmed in fact: a view of downtown New York will not be replaced by a view of rural Vermont if you stick your head out and look off to the left.

In the case of the painting, one can assume there was a model for the painting: what one sees is a fiction based on visual documentation. But even as a work of fiction, the conventions of landscape painting imply that if one could stick one's head through the picture-plane as if it were a window, one would have the same effect as above: the fictional landscape seen in the picture continues past the "window," while the painting itself probably doesn't continue much past the edge of the frame.

In the third case, a scene seen through a window in a stage-set, the set designer is portraying something similar to the first instance, but the portrayal is only as good as it needs to be to fool the audience. Beyond the sightlines of the audience, the backdrop with landscape painted on it is left unpainted, such that an actor looking through the window could clearly see the edge of the artwork, even the edge of the surface the painting was made on. The character that actor plays, however, has fictionally the same experience as the first viewer.

This framing effect, implying a world past what we can see, is basic to "realistic" arts in all their forms. Characters arriving into a scene in a movie or play in mid-conversation imply there actually was a conversation before we heard it. An apartment in a novel or an interior decorator's plan is assumed to be part of a larger building. A person whose mug-shot we see is assumed to actually have a torso.

And territory mapped is assumed to continue past the edge of the map.

The set designer, the landscape painter, and the cartographer are very much aware that their work is creating an illusion of continuity past the picture-frame, while the user does not need to be aware of the falsity of this illusion and in fact needs to ignore it in order to use the picture/set/map as it is intended. I'm thinking this is a major (the major?) divide between creator and user. More on that divide next time.