Light — Science & Magic, 6th Edition

144 THE CASE OF THE DISAPPEARING GLASS

of a piece of glassware does not reect in the direction of the viewer. Such an

edge is invisible. An invisible glass has no shape or form. To make matters

worse, the few tiny reections we do see are oen too small and too bright

to tell us anything about surface detail or texture.

Figure 7.1 shows both problems. e direct reections of the lights illu-

minating the scene do nothing but distract from the composition. ey are

not adequate to dene the surface of the glass.

e lack of a clearly dened form is an even more serious problem.

With no clear outlines and no marked dierences in edge tonality ...