Degree of Diffusion: From Hard to Soft Light
Diffused light scatters onto the subject from many directions. It shows little or no
directionality. Shadows, if they are present at all, are relatively light. Shadow edges
are indistinct, and subjects seem surrounded by light.
Sources of diffused light are broad compared to the size of the subject—a heavily
overcast sky, for example, where the sun’s rays are completely scattered and the
entire sky becomes the source of light. Fully diffused light indoors would require a
very large, diffused light source close to the subject, plus reflectors or fill lights to further
open the shadows. Tenting is one way of fully diffusing light.
308 ABSOLUTE BEGINNER’S GUIDE TO DIGITAL PHOTOGRAPHY
FIGURE 21.1
Direct light has
hard-edged
shadows.
Directional-diffused light is partially direct with some diffused or scattered rays (see
Figure 21.2). It appears to come from a definite direction and creates distinct shadows,
but with edges that are softer than those of direct light. The shadow edges
change smoothly from light to dark, and the shadows tend to have visible detail.
Sources of directional-diffused light are relatively broad. Indoors, windows or doorways
are sources when sunlight bounces in from outdoors rather than shining
directly into the room. Floodlights used relatively close to the subject are also
sources; their light is even more diffused if directed first at a reflector and bounced
onto the subject or if partially scattered by a diffusion screen placed in front of the
light. Outdoors, the usually direct light from the sun is broadened on a slightly hazy
day, when the sun’s rays are partially scattered and the surrounding sky becomes a
more important part of the light source. Bright sunlight can also produce directional-
diffused light when it shines on a reflective surface such as concrete, and then
bounces onto a subject shaded from direct rays by a tree or nearby building.
Fully diffused light provides an even, soft illumination (see Figure 21.3). Here, the
light is coming from above, as can be seen from the somewhat brighter cheeks, but
light is also bouncing in from both sides and, to some extent, from below. An overcast
day or a shaded area commonly has diffused light.