Introduction to Lighting

Monocular Cues
 
Relative Motion
When an observer moves, the apparent relative motion of several stationary objects against a background gives hints about their relative distance. If information about the direction and velocity of movement is known, motion parallax can provide absolute depth information. This effect can be seen clearly when driving in a car. Nearby things pass quickly, while far off objects appear stationary.
 
Light and Shadow
Closer objects reflect more light than further objects. Thus brighter objects appear closer. This can be achieved through the object being more reflective or being better lit.
When an object casts a shadow on another, we assume that it is in front. This relates to the cue of interposition.
 
Relative Clarity
“Fuzzy” objects appear further than “sharper”, clearer objects. This is noticeable when people try to judge distances in fog, mist or rain.