Plein Air Painting Easels

Back to



  home easel reviews contact

November 2008

The Incidence of Angle

Last month we talked about the landscape being essentially an arrangement of three or four large masses, with each mass having its own unique value (lightness or darkness). We also discussed how the value of each mass is determined by how much light it receives from the sun. This can be called the “incidence of angle”. In the demonstration provided, the sun was essentially overhead, thereby throwing its strongest light on the flat ground (lightest value), and the least amount of light on the upright forest mass (darkest value). It all sound pretty straight forward, but we know from experience that it’s seldom that simple. 

Take for example, when the sun is low on its arc (early morning, late afternoon); the foreground, receiving the least amount of direct light, becomes the darker value, while the upright trees take a direct hit and become the lighter value.  A dark, stormy, distant sky, with a sunlit foreground, can tip the equation in a completely different direction. The variations are endless. What remains consistent is the incidence of angle.

Our job, as artists, is to recognize the major masses in a landscape, and the value peculiar to each, and to organize those masses into a dynamic and pleasing composition. The operative word here is “mass”. If the masses are consistent in value, the final painting will have solidity. If not, the design will be compromised and the painting can have a fractured quality.

Some difficulty can arise when we introduce objects (structures, people, animals etc.) into our landscapes. The incidence of angle applies to them also. However, we can, at our discretion, emphasize the importance of these objects to enhance the impact of our statement. For instance, some objects may blend into one of the large masses, while others may have edges, colors or highlights that make them focal or balance points. This requires planning and discretion. Too many scattered points of interest can splinter an otherwise cohesive painting.

Last month, I mentioned that, since all the planes of a landscape receive their light from the sky, the sky is the lightest mass in the landscape. Well, it’s always the exception that proves the rule. And that glaring example is snow. A white mass of snow is much lighter than any part of the sky, except right next to the sun.

To punctuate this, I selected a snow-covered farmyard in late afternoon light for this month’s demonstration. The scene encompasses most of the principles that we have discussed thus far, and offers a different angle of incidence from last month’s demonstration.

There’s a reason that Stanley Kubrick filmed most of his movies in the early morning and late afternoon. The low angle of the sun offers a play of shadow and light that creates wonderful drama. It’s my favorite time to paint on location. However, the light changes rapidly at these times of day, and an artist must work quickly to capture the swiftly changing scene.

The slanting light, snow and multiple structures offers some interesting problems. So, to organize my thoughts, and to simplify some of the complexity, I paint a quick fifteen-minute value study.

This gives me a working reference to utilize while I’m painting the final piece.



Step One:

I begin by washing clear water over the page, from the top of the barn to the bottom of the sheet. I immediately drop in some very light tones of primaries into the barn and the light-struck snow areas of the roofs.

Sometimes using the white paper for snow can leave those areas cold, stark and flat. Although the colors I drop in are high key (and will be barely noticeable in the final product), they will really enliven the light-struck snow masses. So, I resign myself to the fact that there will be no pure white paper left at the finish of the painting.

While the bottom of the page is still wet, I jump right in to the shadowed foreground with cerulean blue and alizarin crimson, working it down to its correct value. Closer to the buildings, I stroke in some yellow ochre and cadmium orange. At this point, it seems out of place, but it will ultimately help to connect those warm buildings to the cold foreground.

Then I go right to the top of the page and paint my sky area with cerulean blue, hansa yellow light and a touch of yellow ochre.



Using the same foreground mixture and a touch of yellow ochre, I darken down the snowy roofs of the outbuildings, leaving the snow on the barn untouched. I now paint the buildings; using cadmium yellow, light red, burnt sienna and touches of cerulean blue. There are two or three applications of paint (over painting) on the barn, to give it more character, and a more weathered feel. I sculpt the snow around the buildings with some darker shadows.


When this dries, I go after the forest with a large brush, using cadmium yellow, light red and ultramarine blue. I employ some scratching, scumbling and splattering to give the mass some interest. I have to be careful, because this process is a lot of fun, and it’s easy to create so much interest in a area that it that it draws too much of the viewer’s attention. I only need enough to be convincing. It is important to remember that using these “tricks” is only a means to an end, and not an end in itself. 



Now it’s just a matter of finishing up. I put some windows and a door on the barn. I model the two snow banks at the base of the barn, and dry brush some weeds. Then I move to the foreground and scumble in some brush, using light red and cerulean blue. Although the brush is dark, I keep it considerably lighter than the background forest. This helps to integrate it with my foreground.

Note how those warm tones in the snow in the center of the painting assist with the transition from the warm, upper part of the painting to the cool foreground.



This is an oil painting of the same scene:


“Snow Covered” 11x14 oil


So recognize your light source, its incidence of angle and how it impacts each of the large masses in your landscape.


Happy painting!