What is Atmospheric Perspective?

Go outside and look at the air around you. Can you see it? Most of us grow up thinking that air is invisible, but it isn’t. In fact, air is one of the most important cues we use to judge the depth in an image we’re looking at.

Look at this photo I took from a hotel room window in Los Angeles. The colors of the buildings and cars that are closer to the camera are vivid and high-contrast. However, the buildings, trees, and hills in the background have a smoky appearance, losing their color and definition.

These images of Sabino Canyon in Tucson, AZ, show a similar effect. Objects close to the camera show a full range of colors and light and dark values, while the mountains in the background are hazy with less difference between shadows and highlights. Also notice that the way you can tell which mountains are closer to you and which are further is by noticing how hazy they are.

Atmospheric perspective is caused by the fact that the space surrounding the solid objects that we see isn’t empty. Light scatters around between air, water, smoke, dust, and pollution molecules, partially obscuring the objects that they are in front of. The further away an object is from the viewer, the more obscure it becomes. Eventually, especially on foggy days, entire buildings and mountains can become completely invisible!

Visually, there are three primary effects caused by atmospheric perspective:

1. The further away an object is, the closer its color will match the color of the sky.
2. As an object moves further from the viewer, the contrast between its highlights and shadows will decrease.
3. The colors of objects that are closer to the viewer will be more saturated (less gray) than the colors of objects that are far away.

Creating Perspective with Layers