What are some of the principles underpinning how artists portray shadows?
In the previous two posts (see Parts 1 and 2), the discussion addresses the fundamentals—the “nuts and bolts”—of portraying shadows. For this final part in the discussion about shadows, the focus is on the conventions underpinning artists’ use of dramatic lighting (in the sense of strong contrasts of light and dark associated with the theatre) technically termed “chiaroscuro.”
There are many subtle conventions associated with this term first coined by Roger de Piles in Débat sur le coloris (“Dialogue on Colours”) in the early 1670s, but for the following discussion I will concentrate on only two conventions that I find fascinating: the social implications of light and shade; and, the associations of an immediate past, present and future through use of light and shade.
Regarding the social implications of light and shade, an artist’s use of chiaroscuro lighting in an image can help to project meanings that have deep resonance with our feelings of empathy for others. For instance, the raking light from the top-front-left portrayed in Lepère’s woodcut, After the Statue by A. Rodin (shown above and based on Auguste Rodin’s famous sculpture, Eve—see http://de-lusionsofgrandeur.org/Eve-1898 and http://de-lusionsofgrandeur.org/Eve [viewed 3.2.2013]) adds a note of emotional tenor to a viewer’s reading of the figure in the image. For me this emotional tenor is all about perceiving the portrayed sculpture as alive and in a state of furtive unease. This is due partly to the body-language of the sculpture's pose and to Lepère’s low viewpoint. But the critical component in projecting its life-spirit is the way that the extreme angle of lighting accentuates the ridges of muscle and bone on the figure’s back (see detail below). In short, Lepère’s very dramatic lighting invites the viewer to engage in subjective readings about very human concerns because the viewer's eye is focused on specific parts of the figure. By contrast, if the sculpture were illuminated by ambient or clinical lighting, as is often the case with scientific illustration, then the same implications may not arise.
Details of Lepère’s woodcut, After the Statue by A. Rodin
Compare, for instance, the subjectivity of readings arising with Lepère’s chiaroscuro woodcut with the comparative objectivity of readings arising from the illumination in G de Roton’s hyalograph—a hybrid process of cliché-verre (i.e. using a drawing on a glass plate as a photographic negative) involving transferring an image to a printing plate that is then etched like an aquatint—Mercury (shown below).
Detail of de Roton’s hyalograph, Mercury (after François Rude)
Use of chiaroscuro lighting may also be focused on giving social status to a subject and this is explained well and insightfully in John Barrell’s (1980), The Dark Side of the Landscape: The Rural Poor in English Painting 1730–1840, Cambridge University Press,
. The important point that Barrell makes is that artists use light and shade as a way of editing what viewers should and should not see. Usually the patron obliges the artist to ensure that the key subject to be portrayed is fully visible, regardless of whether this be a house, horse, property or person. The censored elements are those details that are socially inconvenient, such as unhappy farm workers, other people’s property interrupting a view and the full spectrum of disfiguring lumps and bumps that may be evident on a subject. Cambridge
Like a spotlight in a theatrical production, artists use chiaroscuro lighting to draw attention to critically important elements in a scene while shadow is used to make the remaining features less noticeable. For example, note how Valentine Green in his mezzotint, Frederica Charlotte Ulrica, Duchess of
York and (shown below and discussed in the earlier post, 18th century Photoshop) spotlights the duchess in her rich gown while casting the surrounding landscape in shadow. Compare this chiaroscuro treatment of the lighting with what would happen if the background were illuminated with the same level of intensity as the duchess, as shown in the digitally modified image further below. From my standpoint—and hopefully that of most viewers—the outcome of the experiment is that eye is lost as to what to look at as all the features in the image compete for attention. Albany
Valentine Green (1739–1813)
Frederica, Duchess of
After Sir Joshua Reynolds
Mezzotint on laid paper
63.4 x 38.8 cm
|Digitally altered tones in Green’s Frederica, Duchess of |
Chiaroscuro lighting can also play an even more pivotal role in images based on a narrative. For example, Paul Delaroche’s famous—perhaps even iconic—The execution of Lady Jane Grey translated into the print, Jane Gray, by Paul Mercury [Mercuri] (shown below) is instantly understandable because of the lighting arrangement employed. Certainly the arrangement of the figures in the scene and their body language visually articulate the grisly fate in store for Lady Grey, but, as is demonstrated in the digital alterations to Green’s print above, the eye needs to be guided when looking for meaning.
The principle of guiding the eye across an image is all about establishing a hierarchical order (i.e. a “pecking order”) in terms of which of the portrayed features should be looked at first, second and so forth. Clearly, Lady Grey is the main protagonist in this drama and, consequently, she is portrayed in so much light that she literally glows. Interestingly, in Paul Delaroche’s painting, The Execution of Lady Jane Grey (see http://en.wikipedia.org/wiki/The_Execution_of_Lady_Jane_Grey), the lighting is less of a glowing phenomenon and more of a shaft of light illuminating her. With regard to the other figures in the image, each is portrayed with progressively diminishing levels of illumination as shown in the details below. Interestingly, there is a formula for adjusting the degree of illumination away from a point source of light and this is explained in the earlier post Inverse-Square law.
Details of Mercury’s Jane Gray
Regarding how artists can use chiaroscuro lighting to express notions of time, in the sense of an immediate past, present and future, I wish to revisit the earlier post, Saints & Sinners. In that discussion I proposed the argument that because Occidental folk begin their reading of images from the left, the left side of images must always be “a moment ago” in a left-to-right reading and thus the left side signifies an immediate past. Conversely, using the same logic, the right side of an image must always be a moment of looking about to happen and thus it signifies the pending future.
Following a similar line of argument, the Western lighting convention, discussed in the previous two posts concerning shadows (Parts 1 and 2), is based on the “rule” that the left side of an image should be portrayed as well-lit whereas the right side should be portrayed as shadowed. In terms of connoting past, present and future, this convention functions in tandem with a left-to-right reading direction. In essence, the lighting convention enhances the notion that the imagery on the left—the immediate past—is observable and thus a part of our acquired memories while the imagery on the right— the pending future—is partly concealed by shadow and thus it is not fully comprehended.
An important approach to image making that marries the Occidental reading direction with the Western convention of lighting is the use of pictorial zones arranged as a transition from left to right in incremental stages across an image as outlined in the early post, Pictorial Transitions. This arrangement helps to articulate the idea of a transition in the viewer’s reading from left-to-right involving a shift from an “saturation” phase in perception on the left side through to a “prognostication” phase on the right side.
Like all theories, however, whether they are folly or fact is best examined by their effectiveness in practical application. To illustrate how an image may express the notion of a passage of time, I have selected Frank Brangwyn’s lithograph, The Mine (shown below), and I will leave the question as to whether it is successful in this mission to the reader.
In The Mine, strong light from the top-front-left—the Western lighting convention—illuminates a night scene inviting a viewer’s eye to negotiate meaning from the left to the right side of the image. This arrangement of lighting sets the scene for the reading discussed above from an “immediate past” to a “pending future.” Featured in the foreground is a bustling horde of mineworkers moving from the well-lit left side of the image—the past—on their way towards an undisclosed destiny—the future—through the shadowy right side. Augmenting this left-to-right reading are the pictorial zones (see attributes of each zone in the details below): “saturation”; “incubation”; “illumination”; and, “prognostication” (as explained in Pictorial Transitions). These pictorial zones visually articulate and mimic the notion of the artist’s developing perception of the scene—a compartmentalisation of how one’s perception may arise that was first proposed by Herman von Helmholtz (1821–94) and outlined by Betty Edwards in Drawing on the Artist Within (1986) (see pages 2–5) with a touch of minor meddling by the present author.