The most underrated book about the most underrated art form in America is Scott McCloud's Understanding Comics (Harper Paperbacks, 1994). Behind the seemingly mundane medium of comics lies a fascinating art form, and McCloud provides an excellent explanation for how visual imagery and symbolism create communicate in sequential art. While the book provides many concepts that could be transferred to the realm of film, one of its most illuminating explanations is the role of representation and symbolism.
In his book, McCloud provides a map of visual iconography (i.e., pictures, words, symbols) that he calls the Big Triangle. On one end of the triangle's base lays a spectrum of images that spans from visual resemblance (e.g., photography and realistic painting) to iconic abstraction (e.g., cartoons). The closer the visual representation comes to the level of iconic abstraction the more the observer is able to use their imagination to "fill in the details" and allow themselves to identify with the image. Visual resemblance narrows the level of identification while iconic abstraction broadens it. Think, for example, which smile is more representative of a particular emotion: the complex smirk on the face of the Mona Lisa or the simple curve of the "Have a Nice Day" face?
This notion of identification is useful for understanding the core problem with sexual imagery in cinema. As images become more graphic or visually iconic, the viewer becomes less able to directly identify with the characters involved. On the most extreme end of the spectrum—the purely pornographic movie—the concept of identification borders on the absurd. No one who watches such a film can identify with the characters since the "actors" have been reduced to mere objects.
The problem for pornography, however, is not simply that it lacks a plot. Even in a film where we have already built a bond with the characters, we lose the connection when a shift is made to graphic sexual imagery. No matter how thoughtful the transition, the awkwardness breaks the director's spell.
Observing any work of art requires taking a particular point-of-view. For example, if we were to stand to the side of a painting that requires depth perspective (e.g., the School of Athens), we would lose the effect the artist intended. The same happens when we view a photograph of a sculpture. By squeezing a three-dimensional object into a two-dimensional form, the work loses the aesthetic force of its visual effect.
A similar effect occurs when we view images of sexual activity. Since the act of sex is intended to be engaged in from a first-person perspective, viewing the act from the third-person causes it to lose its power and inherent connection. Sex is designed by God to be an action that is performed by a man and a woman—not as act to be observed by an outsider. Because of this, no artist—no matter how gifted or sensitive—is able to overcome the natural limits of perspective.
By combining these two concepts (visual iconography and perspective) we can begin to understand why sexual imagery is inherently ineffective in film. Since sex doesn't elicit a particular emotional response with which we can identify (in the way that images of violence, for instance, can stir up feelings of empathy), we are forced to imagine ourselves in such a situation before we can properly identify with it. But the combination of a specific visual image (the actors) and the third-person perspective keeps us from forming the emotional connection necessary to fully appreciate what is being conveyed.
Ironically, the prudishness of the early era of motion pictures helped to ameliorate this disadvantage. Since the decency standards required sexual acts to be hinted at rather than expressed openly, the viewer was better able to put themselves in the place of the film's characters. The audience had to "fill in the details" in the same way that would be required in less visual forms of art, such as literature. Though the connection was made on the subconscious level, it was still drawn from a first-person perspective, allowing the viewer to gain a deeper emotional appreciation and connection with the characters.
Portraying sexual relations is necessary in film, because sex is a part of our world and a primary aspect of life. Some of the greatest works of literature (including the Bible) have sex as an important theme. It would therefore be unduly limiting to exclude such motifs from film. For a work in the medium to rise to the level of great art, though, filmmakers must learn how to portray sexual relations in a way that is both realistic and relatable. Doing so will require film directors and other creators to understand how to present sexual imagery in a way that conveys representation, rather than just titillation. In order to move forward with their art, they would do well to look to the formula from the format's past: more intimation, less exhibition.