Relative Clarity (Monocular Cue)

A monocular cue which states that hazy objects are often perceived as farther away than clear objects.

http://www.brianmicklethwait.com/culture/monparl.jpg

In this painting, the slight haziness of the boats make them seem far away from the clearly painted dock, and the very faint buildings and bridge even farther away in the distance.