The art and science of aerial perspective.

I am always looking for ways to see connections and to adapt experiences across different subjects. Combining art with other disciplines helps keep students engaged, even the really analytical and verbal learners. Aerial perspective is an art technique, a scientific principle, and a vehicle for introducing Chinese painting and poetry--something for everyone.

Looking

To start, we discuss Chinese landscape paintings illustrating aerial perspective. Ming Dynasty landscapes are readily available in good reproductions. I also show examples that don't use aerial perspective, such as the landscapes in the manner of Ni Tsan done by numerous Chinese artists.

I ask: Which objects are far away? How can you tell? Which objects are near? Which objects are blurry? Why are some mountains so pale that you can barely see them? We also talk about the use of empty space, the text, and the red seals that are present as artist signatures on Chinese art.

I display photographs of mountain scenery to demonstrate that aerial perspective is a real effect that we see all the time, without noticing it. We discuss how distant objects are more blue in color, lighter in value, and more blurry than close objects. Artists take advantage of this to differentiate distant background objects from foreground objects.

Science Experiment

Why do distant mountains look blue and washed-out? The reason is the same as the reason the sky is blue. Space is black everywhere except when viewed from Earth.

The Earth's atmosphere is composed of molecules of water, various gases, and dust particles. The different colors of light visible in rainbows have different wavelengths and reflect differently when they hit something. As the light passes through the atmosphere towards our eyes, it bounces off the molecules. Shorter wavelengths of light, at the blue end of the spectrum, are scattered more easily by the size of the particles in the air.

So, in effect, the blue part of the light is scattered around the sky from particle to particle, from where some of it reaches our eyes. The same bouncing effect also causes the blurriness of distant objects. When we look at distant mountains, we are looking through more of the atmosphere than when we look at the ones that are close.

In-Class Demonstration

To see these effects, I have students do a demonstration from the Exploratorium, a science museum in San Francisco. They fill a large glass container, such as an aquarium, with water. They set up a flashlight on one side of the container and turn it on so that it shines through the container horizontally. They slowly add spoonfuls of powdered milk to the water, stirring, just until they can see the beam of light passing through the water. From the side, the beam of light looks whitish-blue. If you look through the liquid towards the flashlight bulb, it appears yellowish.

In the side view, you see the blue colors in the light scattering as they bounce off the milk molecules. From the frontal position looking into the bulb, you see the remaining red-yellow end of the spectrum being transmitted unchanged through the water.

Brush and Ink Landscape

Students practice aerial perspective in an Asian-style landscape. They use black ink or paint and water for mixing three different shades, red ink or paint, brushes, and watercolor paper. I give the students ten or fifteen minutes to practice with the materials, creating dark black marks for the foreground and very light grey for the background. They practice sweeping--loose strokes with a big brush to suggest distant mountains and smaller, tighter strokes with a smaller brush for trees and rocks in the foreground. The secret to success is to keep it simple. I remind students that many of the Chinese landscapes that we have looked at have sparse compositions with few details.

After practice, students begin their paintings. I have them start with a very light mountain range in the background and a slightly darker, bigger mountain in the middle ground. They add dark, large details of rocks and trees up front. I encourage them to leave some blank space for their seal and poem.

A Personal Seal

For the seal, we use Xu Bing's system of writing called New English Calligraphy. Xu Bing, a contemporary Chinese artist, explores writing through art by creating realistic-looking Chinese characters that are not actually real. In New English Calligraphy the characters are English words that you can read when you look closely.

The Poem

Finally, students write poems about their paintings. Any format works, though this is a great opportunity to teach them about Chinese poetry. They carefully copy their final draft onto their painting with an ink pen, or type it, print it, and glue it on.

Adaptations

This lesson is very versatile. For example, aerial perspective is also common in Western art, beginning in the Renaissance. Great choices include Leonardo da Vinci and Albert Bierstadt. There are many more optical experiments that you can do to explore light. You can learn about Chinese characters and look at more of Xu Bing's works, most of which use writing in imaginative ways.

Susan Kegel is an art docent at Norman Rockwell Elementary in Redmond. Washington, [e-mail]

WEB LINKS

www.xubing.com

www.asia.si.edu/exhibitions/ online/xubing/default.html

www.exploratorium.org