INTERPOSITION
Interposition creates an 
impression of depth.

 In the photograph shown here, 
each woman partially covers, 
or occludes, the woman behind 
her. The partial covering of one 
object by another, or 
interposition, in pictures leads 
to a definite impression that 
one object is farther away than 
another, as artists have known 
for centuries. A moment’s 
reflection makes clear that it 
will also do so in a real scene.

    The depth implied by 
interposition is logically only 
the thickness of the occluding 
object. Yet interposition is a 
powerful cue to depth, 
experiments show.