In painting the word ‘edge’ generally refers to the level of definition in the separation of one shape of colour to another. Edges exist on a scale. Shapes with perfectly defined boundaries, or ‘sharp’ edges, exist on one end of the scale. Shapes with perfectly smooth gradients connecting them, or ‘soft’ edges, lie on the opposite end of the scale. Between these two extremes lies the potential for infinite variety in the softness or sharpness of a shape. From the day we are born until the day that we die all that we see are shapes of colour that vary in this quality and a true understanding of how to handle this quality will form one of the painter’s greatest assets in the representation of things seen. The full significance of this quality of shapes is often missed by beginning students. Here at LARA this quality is introduced early in our program and stressed throughout.
One of the primary ways that edges affect our vision is in the way we perceive the character of the forms that we look at. As we can see in the example above, on the left sharper, more defined edges tend to suggest more planar, hard surface forms. On the right we see that if we take the same value structure and lighting set up and this time soften the transitions between the values we are given the impression of a soft form with a more rounded surface.
Many painters throughout history have relied heavily on this approach to edges, considering them as a product of the character of forms. While this concept alone is capable of many wondrous effects, on its own it is a slightly limiting view of a quality that is far more all encompassing. It wasn’t until Velazquez that this quality was considered as a quality of its own . As we can see in this wonderful painting by Raphael, great variety in the treatment of the edges within the head and cloth give the strong feeling of varied textures and materials within the painting. However, due to this concept of edges-for-form little thought is given to variety of edges along the contour and they are all treated as equally hard. Contrast that with this self portrait by Velazquez. As you can see, no two edges are treated equally and great variety of edge can be found in all areas of the image, lending his image a more vivid sense of reality. Students should remember to carefully consider their treatment of all edges within the image and not to go with their idea of what an edge ‘should’ be.
One other major consideration with edges is the design of the image. Sharp edges tend to draw the eye and increase perceived contrast in the areas that they are used. As we can see in the diagram on the left of the image above, it is difficult to force ourselves to look at the softer square as the harder one demands our attention. The reason for this is that it mimics the way we see things: our eyes only perceive about 20 degrees of sharp detail
occurring at the centre of our vision – outside of that information becomes blurry and indistinct. This idea of mimicking how we see can be an extremely powerful compositional tool in directing a viewer’s eye around an image. Czech painter Vlaho Bukovac makes use of this in the image above. The only sharp edges to be found in the entire image occur in the centre and the edges soften massively as we move away from the centre. This causes the eye to naturally want to look at this central focal point.
by Charlie Pickard