The difference between linear perspective and aerial perspective is that linear perspective is a technique used to create the illusion of three-dimensional space and depth on a flat surface suing a mathematically based system using a vanishing point on a horizon. Aerial perspective in art refers to a technique used to create an illusion of depth based on the study of optics. Artists can re-create the effects that the atmosphere has on the visual perception of objects at a different distances by adjusting their clarity and contrast (decreasing contrast at greater distance), their intensity or saturation of color, and by increasing their levels of blue. Artists can use either one of these techniques or even combine both methods to create an illusion of depth, depending on their style and subject-matter.