Editing Depth perception (section)

=== Aerial perspective ===
{{main|Aerial perspective}}
Due to light scattering by the atmosphere, objects that are a great distance away have lower luminance [[Contrast (vision)|contrast]] and lower [[color saturation]]. Due to this, images seem hazy the farther they are away from a person's point of view. In [[computer graphics]], this is often called "[[distance fog]]". The foreground has high contrast; the background has low contrast. Objects differing only in their contrast with a background appear to be at different depths.<ref>{{cite journal |vauthors=O'Shea RP, Blackburn SG, Ono H |year=1994 |title=Contrast as a depth cue |journal=Vision Research |volume=34 |pages=1595–1604 |doi=10.1016/0042-6989(94)90116-3 |pmid=7941367 |issue=12|s2cid=149436 }}</ref> The color of distant objects is also shifted toward the blue end of the [[spectrum]] (for example, distant mountains). Some painters, notably [[Cézanne]], employ "warm" pigments (red, yellow and orange) to bring features forward towards the viewer, and "cool" ones (blue, violet, and blue-green) to indicate the part of a form that curves away from the [[picture plane]].