THE CASE OF THE DISAPPEARING GLASS
against a dark background. These two techniques are the foundation for lighting glass. However, we often need additional techniques to produce a satisfactory photograph. In the remainder of this chapter, we will discuss some finishing touches. Specifically, we will examine how to accomplish the following: 1.╇ Define the surface of glassware. 2.╇ Illuminate the background. 3.╇ Minimize the horizon. 4.╇ Stop flare. 5.╇ Eliminate extraneous reflections. Because these techniques are primarily useful in dark-field situations, we will demonstrate them using that approach. Defining the Surface of Glassware In many situations, it is not enough merely to define the edges of a subject. It is not enough just to show its shape, no matter how beautifully we do it. Frequently, the photograph must also clearly show the glass surface. To accomplish this, we must carefully manage the highlights that reflect from the surface of the subject. Large highlights are essential to glass surface definition. To see proof of this, compare the highlights on Figure 7.9 with those seen earlier in Figure 7.1. The tiny bright spots in Figure 7.1 are harshly distracting at the least and meaningless at best. The opposite is true in Figure 7.9. Instead of competing, the larger highlights provide the viewer with information. Rather than cluttering the other elements of the photograph for the attention of the viewer, it serves the constructive purpose of saying, “This is how this glass surface looks and feels.” Defining a glass surface requires a highlight of the right size in the right place on the surface of the subject. Fortunately, that is not too difficult. Doing it successfully simply requires remembering what the theory of reflection tells us about how direct reflection behaves. We have seen that almost all reflections from a glass surface are direct reflections and that direct reflections always obey strict rules that predict the angles at which they occur. Now, look at Figure 7.10. Assuming we want to create a highlight on the area shown on the glass surface, we need to fill the indicated family of angles with light. These are all of the directions and the only directions from which light can produce direct reflection on that part of the glass. Notice that the rounded glass causes this small subject to reflect much of the studio in its surface. For this reason, lighting for surface definition can sometimes require surprisingly large light sources.
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