There is a third principle to be observed when creating the illusion of reality, which is closely aligned with atmospheric perspective. This is the Principle of Selective Focus. It is the phenomenon whereby our eyes, directed by the brain, register the highest attention to detail on whatever we consider most important within our cone of vision. Please note that this process is unique to the natural viewing apparatus. A camera does not operate in the same way. The specific differences will be discussed at length in the chapter on photography. In designing our painting, we must simplify the shapes of lesser importance and render them in softer focus than the areas of primary importance. Hard edges should be used sparingly, and for specific reasons. The use of too many sharp edges destroys the illusion of reality, as it does not correspond to visual experience. Our eyes cannot focus on more than one small area at a time. Everything else appears duller and less distinct. By following this principle, the artist can assign greater importance to key elements in the picture by rendering them in sharper focus and adding more detail, and can arrange things in such a way as to lead the eye from point to point, including areas of secondary and tertiary interest, if desired, to hold the viewer's attention for as long as possible. Areas of secondary and tertiary importance may also be rendered in sharp focus, but must be made less noticeable than the primary subject by their positioning on the picture plane and by arranging things in such a way as to have less contrast of values, lower chroma colors, or whatever other means will render them less noticeable at a distance. Orchestrated in this way, they do not compete with the area of primary importance for the viewer's attention. The main focal point is emphasized not only by sharper focus, but by greater contrast of light and dark, by higher chroma color, perhaps by its juxtaposition with contrasting hue accents, and especially by its strategic placement on the canvas. Other elements in the picture may also point toward it. Thus are the elements of secondary and tertiary interest rendered subordinate, even though they may be rendered in sharp focus in certain instances. Their effectiveness, however, depends on softer focus being used over most of the picture. If one had to choose between painting everything sharp, or everything soft, the soft option would allow for a more convincing illusion of reality. We all, at times, see everything in soft focus, as it takes a certain amount of effort and direction from the brain to focus the eyes on anything. It is not possible, however, to see everything in sharp focus at once; thus, a view painted in such a way clashes with our experiences in viewing the real world. It is easy to fall into the trap of painting this way, for as we move our focus from what we have just painted to what we will paint next, each element appears to us in sharp focus. The temptation to paint it as sharply as we see it when focusing on it is very strong, but must be resisted, or we violate the Principle of Selective Focus, and the illusion of reality of the overall scene will be compromised for the sake of superfluous detail. It is helpful to squint when observing these elements, thereby throwing the eye somewhat out of focus, and then paint them as they appear when squinting. If the painting requires a sharper focus on certain parts of the scene, it is still advisable to begin by squinting, in order to read the larger, more general shapes, and then add whatever detail is desired after we are certain that the big shapes are correct.
We must not lose sight of how our picture will appear to its viewers at first glance. It must register upon their sense of sight just as the scene itself would, or they will not be drawn in to look at it more closely, and will never see to appreciate the fine work we may have put into the details. A picture must be designed to work as a visual whole. It must be more than a collection of details assembled at random. Elements of lesser importance should be simplified, lest they confuse the viewer as to what the subject, or focal point, of the picture is. If the focal point is rendered in sharper focus, and subordinate areas in softer focus and simplified, confusion is avoided.
This follows precisely the manner in which we view a scene with our own eyes. To see something in sharp focus, the brain must direct the muscles within both eyes to simultaneously adjust their respective lenses to focus on that object, and the muscles guiding the position of each eye to allow them to converge on that same object or surface. This involves a certain degree of effort, thus this action is only triggered by the brain when it deems something of sufficient importance to warrant it. Therefore, by rendering a given object or surface in our painting more sharply, we are indicating to the viewer that this particular thing is important. Thus the term, "Selective Focus."
As artists, we should not just paint what we see, we should paint what we want to show to our audience, selecting only that which is worthy of such special attention, and then presenting it as it appears at its most appealing, or making it more so if it will make a better picture. The viewer's attention is directed where we want it by the use of selective focus. If the visions we paint exist only in our imaginations, so much the better.
By understanding the Principles of Visual Reality, one can render imaginary scenes convincingly real, and perhaps transcend even the limitations of working from life. This is the mark of a Master. This level of ability can only be attained by working from life until the Principles of Visual Reality are thoroughly absorbed. There is no short cut.
Of equal importance to the principles governing spatial recession is an understanding of the nature of light and shadow. Three-dimensional form is indicated by the distribution of light. Shadow is, in theory, the absence of light, but in reality there is light in shadow as well. Areas of light are generally illuminated by light rays which have traveled in a straight line from the strongest source, whereas shadows receive their light indirectly, as the rays ricochet off nearby surfaces and bounce in behind objects that block the direct rays, or from secondary light sources weaker and/or farther away than the primary light source. Without secondary light, shadows would read as black. The dark side of the moon is an example. Secondary light is what enables us to perceive form within the shadows.
The shadow is darkest at the just beyond the planes illuminated by the primary (strongest) light source. This area is called the shadow accent (sometimes referred to as the core shadow) of the body shadow. The phenomenon of the shadow accent is best understood in scientific terms. Whenever enough light is present to allow us to see at all, there are light rays coming from many directions, of varying strengths, both reflected and direct, often from more than one source. The strongest light creates what we consider light and middletone areas, whereas the weaker are only visible in shadow. Whatever is blocking the strongest light also blocks a certain amount of secondary light, and the closer the shadow is to the blocking obstacle, the more of the secondary light rays are blocked.
A good analogy is to suppose we are standing under an awning or umbrella in the rain. Our head stays dry, being closer to the awning, umbrella or whatever is blocking the rain. Further down, some rain may reach us, where there is greater distance between a given surface and the awning. If we substitute light rays for rain, it becomes apparent why the shadow accent is darker than the rest of the shadow. Less light means more dark. Beyond the shadow accent, more reflected or secondary light is allowed to enter the shadow area, reflecting off nearby objects or planes, or from secondary (weaker) sources, as the distance from the light-blocking obstacle increases. This light is commonly called reflected light in shadow, although it often includes direct light from weaker or more distant sources as well. Perhaps a more technically correct term would be secondary light. So the shadow accent, also known as the core shadow, is most simply described as the zone of shadow between the primary light and the secondary light.
The shadow accent is a most useful device for describing interior planes, that is, planes within the edges of the object being depicted, by its shape and by how sharply it makes the transition from middletone to shadow. A sharp change in angle will have a sharp transition; a more rounded form would have a softer transition from middletone to shadow. Once the artist understands this principle, he or she will look for the shadow accent, and will use it to good advantage.
The cast shadow follows the same principle as the body shadow (the shadow on the unlit side of the object in question), in that it is darkest at the edge nearest whatever is blocking the light. Its edge is also sharpest at that point, and softens as it recedes from there, due to reflected light from surrounding planes or from secondary sources. The middletone is the area on the lighted side which is far enough from the angle of incidence of the light rays to our eyes that the body color of the object is least altered by the light. Thus the color of a given surface is seen at its highest chroma, or intensity, somewhere in the middletone. This is explained in greater detail in the chapter on color.
The highlight is the point at which the light from the primary light source bounces off the object and to our eyes the most directly. It will contain more of the color of the light source than any other area in the light. The highlight will describe the surface texture of the object being viewed, by the degree of sharpness at its edge, and by the contrast between its value and the value of the middletone. There will be a transition zone between highlight and middletone. The extent of this transition zone, again, depends on the texture and shape of the surface, and on the intensity of the light from the source, striking at the highlight. It is necessary at this point to address the way in which color is affected in the shadow areas. Shadows are areas where the direct light rays from the strongest source cannot reach. If there were but one source of light, and no surfaces nearby to reflect light back into those areas, the shadows would be totally dark, and we could not read shapes within them. However, situations such as that are rare, except in outer space. In reality, there is usually more than one light source, and/or nearby surfaces which reflect light into shadow areas. The color of the secondary light source affects the color of the shadows. The color of nearby surfaces, which reflect light into shadows, is also cast into the shadows as an inseparable component of the reflected light. The body color of the shadowed surface is also an influence; however, its chroma will be lower (duller) than in the middletone for the same reason that its value is lower (darker). The reason is that there is not enough light in the shadow to reveal the body color at its full intensity.
The strongest influence on the color in shadow is usually the color of a secondary light source. The best example is an outdoor scene on a sunny day. The main light source is direct sun, which is slightly yellowish. The secondary light source is the sky, which is blue. The color of the sky will be the strongest color influence, other than the body color of each surface, in all areas facing it not lit by direct sunlight. The sun's rays, striking directly, are so much stronger than the light of the secondary source (the sky) as to effectively overcome the color influence of the sky in those areas, replacing it in the highlights with its own color plus white. In other words, direct sunlight "eats" the blue. When a cloud obscures the sun, the sky becomes the primary light source, and its color, blue, becomes an influence in the lighted areas, until the cloud moves away and allows the direct rays of the sun to again eat the blue. All areas then in shadow retain the blue influence of the sky, except where the light from the sky cannot reach. In those areas, reflected color will have a stronger influence. For example, the underside of an object surrounded by a green lawn will register a certain amount of green in the shadow areas, whereas the upward-facing areas in shadow will register the blue of the sky. The green is carried with the light from the sun as it bounces off the lawn, reflecting into nearby surfaces. If the object has no color of its own, such as a white or grey statue, this will be more apparent. If the object has its own body color, it will be influenced by the color of the secondary light, but not replaced by it.
After the student has been exposed to these principles, they will become more obvious, as he or she will be on the lookout for them. This is an important step toward becoming an artist. Once the Principles of Visual Reality are completely understood, the artist is freed from dependence on external sources. Nothing the imagination can conjure up will be beyond the artist's ability to depict on canvas. This in itself is still no guarantee, however, that an artist so equipped will be a Master, as he or she must also have something of interest to say. Inspiration is an individual thing that cannot be taught. One finds inspiration on one's own. However, all the inspiration in the world will not help, if the inspired person lacks the vocabulary to express it. An understanding of the Principles of Visual Reality is an extremely important part of that vocabulary.
Detail from "The Songstress" by Virgil Elliott GO TO ... Techniques of Painting in Oil
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