As a visual artist and photographer, light is the primary resource of your
craft. Therefore, photographers tend to speak of light in more emotional
terms such as hard or soft, warm or cool, romantic or harsh. To understand
thingslikecolortemperature,color-balancing filters,andwhite balance,how-
ever, it’s useful to be familiar with the physics of light. This is because light is
what produces color. In fact, when we talk about color, we are actually refer-
ring to wavelengths of light that produce a particular color. For example,
whenwetalkaboutsomethingbeing“blue”wearereallysayingthatthelight
it reflects to our eyes is of a wavelength that elicits the sensation of blue.
How Light Behaves.
Four different things can happen to light waves when they strike a surface:
they can be reflected (or scattered), absorbed, refracted,or transmitted—and
more than one of these can happen simultaneously. Understanding how this
works, and how to predict it, is key to photographic lighting.
Reflection.When light hits a flat, reflective surface (like a mirror), the re-
flected waves will always come off the flat surface at the equal and opposite
angle at which the incoming wave of light struck the surface. Knowing this
can help you eliminate or create reflections that are visible from the camera.
Scattering is basically reflection off a rough surface. Because the surface is
uneven, light waves that strike it are reflected at many different angles. When
you use a white board (a matte white reflector) this it what happens—it scat-
ters the light and makes it more diffuse (softer).
Translucent surfaces, like the nylon used in photographic umbrellas and
softboxes, transmit some of the light and scatter some of it. Because some of
the light waves are scattered they strike the subject at many different angles,
which is what makes the light softer and more diffused than without a soft-
box or umbrella (more on light modifiers in chapter 5).
Refraction.When light waves move from air to glass (which is more
dense), the light slows down. If it strikes the glass at an angle, it will also
change direction. This is known as refraction. Knowing how glass elements
will bend light allows optical engineers to design camera lenses. Refraction is
also used in spotlights and spots with Fresnel lenses, which focus the light
into an intense beam.
Absorption.When light isn’t reflected or transmitted, it’s absorbed. This
is why black velvet backdrops, which absorb virtually all of the light that
strikes them, are often used in photography.
Quality of the Light.
Lighting is generally defined as being hard or soft. Hard light creates deep,
crisp shadows (the difference between highlight areas and shadow areas is
sharply defined). This creates a dramatic look with high contrast that tends to
32 LIGHTING TECHNIQUES FOR PHOTOGRAPHING MODEL PORTFOLIOS
As a visual artist and
photographer, light is
the primary resource
of your craft.