Figure 3-4. Lighting textured surfaces
e. The angle should be increased when the surface of the original is very smooth (fig 3-5).
Smooth surfaces reflect light, so you should use a more oblique light to prevent surface reflection from
spoiling the copy.
Figure 3-5. Lighting smooth surface
f. Place lights equal distances from the original if they are of equal intensity (fig 3-6). When
the intensity is not equal, place the brighter light farther away so the illumination of the original from
each light is the same (fig 3-7). Illumination decreases with the square of the distance, thus you can
obtain the same illumination of the original by placing a light that is four times brighter, twice the