Thursday, August 28, 2008

How to Oil Paint -- Art Instruction -- Color Theory in Perspective - Aerial Perspective

Todays post is very useful for learning about why we see things as they are... but first I'd like to introduce you to my etsy shop where you can buy beautiful prints of my favourite paintings. Feel free to browse and even buy for a friend or yourself, they make great presents at affordable prices, if you are stuck for what to get someone.

Also see my Art Designs on clothes for sale. Visit http://shopvida.com/collections/voices/jim-shanahan to purchase beautiful designs of my art on clothing. Beautiful flower designs and others on scarfs and tops. Enjoy and have a chance to buy a unique item - not available anywhere else or in shops, created by me!!

Aerial Perspective

Creating the illusion of three dimensional distance on a two-dimensional surface is not an easy task. It helps to follow simple rules relating to what is known as aerial perspective. Aerial perspective doesn't mean aerial viewpoint! Here's a little background theory.



At midday we notice the most intense blue sky. White sunlight is travelling through the air and certain wavelengths are being scattered by the atmosphere. Small oxygen and nitrogen molecules scatter the shorter wavelength rays, the violet and blue portions of the sun's light. These bluish light rays bounce around everywhere and create the blue sky we see. But why is the sky not violet then? Actually our eyes are more sensitive to blue and the sun emits more blue light than violet so blue predominates in the light that is scattered. At sunset the rays have to travel through more atmosphere to reach our eye, so all blue is lost (refracted / scattered) and what remains is the red / orange rays. Hence red sunset! Simple enough.


So what does that tell us..
Well during daylight, that there is a lot of blue light particles scattering around in the atmosphere around us. So if we look at something they are in our line of sight. Each contributes a little blue to what we see. The further away an object is from us, the more of these blue light particles are in our way making the object take on a bluer appearance. Hence the faraway mountains appear blue. Yellow is the first naturally occurring colour to disappear due to this blue effect, as yellow and blue make green - so yellows become greener and fade. Red is not commonly found in nature, but it changes to purples or browns, losing intensity with distance.

Now to complicate things a little more. This explains the major effect of aerial perspective. But there are some minor effects. With distance less light of any colour reaches us, so colour becomes less intense, even as it tends to blue. So colour in general fades. The more light an object emits the more this is evident, and the object blends more with the surroundings. White objects emit the most light, all the wavelengths, so the contrast between them and surroundings is reduced the most. Black objects absorb light so are actually absorbing some of the blue and hence a slight increase in contrast is created between them and surroundings! Nevertheless this effect is minimal compared to the first blue haze effect. But it does mean contrast between light and dark is greatest up close, so worth bearing in mind.


What happens at night? Well if the object is black not much! You can't see it. But if an object is luminous or emitting light of any description, most lightly due to reflecting light from a light source, then that light is not passing through an atmosphere full of blue light particles as there is no sun. A full moon might act a little like the sun but generally speaking it has little influence. What does happen is that as before light reaching you from the object is scattering - the atmosphere is still there! So the light with longest wavelengths reaches you most easily. These are reds, browns and yellows. Mostly shades that tend toward dull reds and browns reach you.

Well thats about it for the understanding. Have a look at the photos for the reality of what it means to colour choice in landscapes. Also don't forget, feel free to check out my etsy shop for beautiful prints of my paintings.

Also see my Art Designs on clothes for sale. Visit http://shopvida.com/collections/voices/jim-shanahan to purchase beautiful designs of my art on clothing. Beautiful flower designs and others on scarfs and tops. Enjoy and have a chance to buy a unique item - not available anywhere else or in shops, created by me!!

Here are some other articles that might be of interest.
Landscape Oil Painting Demonstration
Landscape Painting showing Aerial Perspective
Seascape showing some Aerial Perspective
Seascape 2 showing Aerial Perspective



2 comments:

Helen Read said...

Great explanation, Jim! Thanks for putting it down so clearly.

Margaret said...

excellently well said :)