Creating a sense of depth and distance with pastel landscapes - "Sunset" WIP4-6

How do you make objects or elements of a landscape appear 'far away'? Why do mountains appear blue from a distance? Why are they called the 'blue' mountains?

One of the great challenges for the landscape artist (and I am very much beginning along this road) is to create a sense of depth in their paintings. The viewer should feel as though they are looking through a window at a scene, or better yet, that they are surrounded by the scene, rather than peering at a flat canvas or board. Often the upper third or two thirds of the painting consists predominantly of sky or distant horizon elements (such as ocean or mountains). The goal then is to create a sense of 'openness' and freedom in these sections. How can this be done?

To work out how to create a sense of distance, it is helpful to understand how our eyes perceive distance, and what makes far away objects appear so. As light travels through gases such as air, that light is scattered by tiny particles within those gases, including water droplets, dust, smoke etc. This is known as Rayleigh scattering. Light travelling a short distance from an object to our eyes has to pass through less air to reach us, and hence there is less chance for that light to be scattered before reaching us. Light travelling a longer distance has a greater chance of being scattered. This is why objects that are further away appear to have less contrast overall than objects that are close up. The scattering of light tends to even out the bright and dark areas.

The scattering also affects the colours we perceive a distant object to be. Colours of an object are simply a property of the light that is reflecting or bouncing off from an object or the region where an object is located (except objects that emit or transmit light). While mountains covered with trees and bushes generally appear green when we're up close to them (and the rocky parts appear brown or grey), further away, they tend to become more blue in appearance. This is because short wavelength light (such as the blue end of the visible electromagnetic spectrum) tends to be scattered much more readily than longer wavelength light (such as red light). When we look at a distant object, we see not only light reflecting directly off the object, but also a lot of scattered blue light reaches our eyes, making the object appear to have a bluish cast, or haze.

The colours of the sky in daylight and at sunrise and sunset are caused by a similar principle, except that there is no 'object' to observe but the atmosphere itself. Were the atmosphere not present around Earth, when we looked up at the sky during the day, we would likely see black (or the absence of light). Sunlight reaching us by being scattered through the atmosphere at noon appears blue due to the blue wavelengths scattering the most. However, sunlight that reaches us from an even longer traverse through the atmosphere at sunrise and sunset appears red because at such a great distance, the air particles that make up the atmosphere have long since scattered all the blue light from its original direction, and only the longer red and yellow wavelengths reach us. Light coming towards us directly from the sphere of the sun itself (either at noon or sunrise or sunset) typically appears white or yellow because it is so intense that it still contains all the colours in the spectrum (despite some scattering); and the full spectrum together appears white.

So how can this help us in creating depth in our paintings?

Distant objects usually appear to be covered in a 'haze' that makes them:

More blue in colour (or cooler hues of related colours)
Paler or more 'pastel' coloured overall
Less contrasting (less bright white and dark black areas)
Have less well defined edges

I have tried to apply these principles to my pastel landscape painting of the blue mountains in New South Wales, Australia ("Sunset", WIP 4-6). I laid the foundations of the landscape by blending the background colours (see previous post for work in progress shots), ensuring that the most distant mountain was the most pale in colour, and had the least definition. The mountain edge in the middle distance was going to be my focal point, so although it was still blue and pale, I retained its sharp profile. The foreground cliffs are a much warmer colour and more representative of the reds and browns of the rock and 'true' green of the trees and foliage.

I decided I wanted a more dramatic broiling sky (see WIP 4) so added more lights and darks. At this point I also altered the original shape of the middle mountain.

Next I worked on the foreground, adding a tree on the left to 'place' the viewer in the scene, and more detail in the close up cliffs (WIP 5).

Lastly I worked on the focal point - the tiny but distinct trees on the edge of the middle mountain (WIP 6).

I loved the way they almost appeared to be falling off the cliff faces, tumbling down, pushed by the wind and rain and their absence of good grounding. I used fine pastel pencil to add these details in pale blues and greys.