Lighting Worksheet 1
Lighting can emphasize important details or hide them. It can flatter a subject by bringing out positive
attributes and it can de-emphasize or hide less attractive attributes. Lighting can even impart a sinister and
hostile look.
It all depends on how you choose to use the concepts we'll be covering in the next few modules.
Television is based on the medium of light; in fact, without light there could be no video.
Just as sound must be skillfully controlled in audio production, light must be expertly controlled in television.
As video — especially HDTV — has begun to emulate the more artistic dimensions of film, there has been a
greater emphasis on creative lighting.
But, before you can successfully control light, you need to understand and control its three basic
characteristics:
 coherence (quality)
 color temperature
 intensity
Coherence
Coherence, often called quality, is the hardness or softness of light. Light quality is probably the least
understood and the most neglected of the three variables.
In the photos above the objects are exactly the same. Two of the variables of light are also exactly the same:
intensity and color temperature. The only difference is the third variable: the coherence of the light.
The first photo was shot with soft light, the second with a hard light source. In Module 35, "Altering
Appearances," we'll look at additional factors that can affect the appearance of subject matter.
Hard Light
Light that is transmitted directly from a small point source results in relatively coherent
(parallel) rays. This gives the light a hard, crisp, sharply defined appearance. The light
from a clear, unfrosted light bulb, a focused spotlight, or the noonday sun in a clear sky,
all represent hard light sources.
Hard light casts a sharp, clearly defined shadow. When hard light is used to illuminate a
face, imperfections in the skin stand out. The result is less than flattering. But in other
applications, such as bringing out the texture in leather, or the engraving on a piece of
jewelry, this can be an advantage. Note in the photo on the left how the writing stands
out.
Also note the clearly defined shadow of the flower at the bottom of the photo. Compare this photo with the
one in the section below (with soft light) where the letters are hard to read and the shadow of the flower has
all but disappeared. Several types of lighting instruments are used in TV to create hard light, including the
beam-spot projector and the ellipsoidal spotlight.
Soft Light
Soft (diffused) light has the opposite effect. As shown in the photo on the left ,
soft light tends to hide surface irregularities and detail.
Spun-glass diffusers(right) are used over the
front of lights to soften and diffuse their
beams. At the same time, diffusers also reduce
the intensity of light.
Soft light sources are used in production to
create a broad, even area of light. In the field,
videographers often rely on umbrella reflectors
(on the right, below) to create a soft lighting effect. As you can see, this is simply
a light bounced off the inside of a silver or white, umbrella-like reflector.
The illustration below on the left shows a LED soflight which consumes much less
power and generates much less heat than incandescent versions. The life span of
LED lamps is rated at 100,000 hours and they can be readily switched from daylight to incandescent color
temperatures (a topic taken up in the next module). Although in their basic form these LED lights are nondirectional, the light output of some versions can be directionalized or focused, which means they are
effective at greater distances.
Because soft light tends to hide lines, wrinkles and blemishes, it's desirable in doing
glamour work. The photo of the model on the left was shot with soft light.
A soft light source placed close to the camera minimizes surface detail. The effect is
commonly referred to as flat lighting.
Although it has certain applications, especially in extreme close-ups of objects where
shadows would obscure important details, flat lighting leaves subject matter somewhat
"dimensionless." When used over a large area, it can impart an arid and sterile-looking
appearance.
Color Temperature
Although the second attribute of light, color temperature, refers to its basic color, we're
also speaking of a characteristic of light that goes beyond the obvious. For example, in
the photo on the right both sources of light (sunlight on the right; a standard light bulb
on the left) normally appear as white light to the eye.
It's only when we see them together as we do here that the difference in color
temperature becomes obvious. As we've noted, under normal conditions when we look
at subject matter such as this, approximate color consistency comes into play and
automatically makes a perceptual adjustments for these different sources of light.
Strangely, and maybe unfortunately, when we look at video or film, approximate color consistency doesn't
work in the same way. Unless color corrections are made, we'll notice significant (and annoying) color shifts
between scenes when they are cut together. Although light can be any color between infrared and ultraviolet,
there are two basic color standards: 3,200K (Kelvin) for incandescent lamps used in studios
and 5,500K for average daylight.
Artificial Light Sources
We mentioned that 3,200K is the standard color temperature for TV lighting -- considerably lower
(redder) than average daylight. Note the high proportion of yellow and red in the incandescent area of this
illustration. This artificial type of lighting is commonly referred to as incandescent light, or, after the coiled
tungsten filament in these lamps
Not all incandescent light is 3,200K. A common 100-watt light bulb,
for example, is only about 2,850K. A candle flame (for those of you
who have a need to shoot productions under candlelight!) is even
redder-- about 1,900K. Most of the differences in these sources
can be handled by the built-in "indoor-outdoor" color correcting
filters of your camera together with white balance circuitry.
CFL or Compact Fluorescent Lamps
With energy saving compact fluorescent lamps (CFLs)
seemingly destined to replace most tungsten lamps in the coming years, the color temperature characteristics
of these lamps are now significant in videography.
The majority of CFLs on the market are between 2700K and 3000K, which is comparable to an incandescent
bulb.
However, "bright white," "natural" or "daylight" CFLs are also available in higher Kelvin color temperatures:
3500K, 4100K, 5000K, and 6500K.
The latter enhance cooler colors -- blue, green, and violet, and dull down reds and yellows.
Because they are essentially fluorescent lamps, they have a broken spectrum that can result in unexpected
color shifts with film and video. (Note the discussion of fluorescent lamps below.)
Before CFL lamps are used in critical color work the result should be checked on a good color monitor. If the
color balance is not what you want, you should substitute lights of known color characteristics.
Intensity
The third and last lighting variable is intensity. As we will see, the
control of light intensity (or quantity) represents a major variable
in dramatic production. For example, in the photo (on right) the
inside and outside illumination levels have to be carefully
balanced to keep one from overpowering the other and spoiling
the effect. Note how the different color temperatures (blue for
moonlight, reddish for interior light) are also important to the
effect. Although these things are easy to see in the photo, in an
actual setting the eye ends up being a poor judge of both relative
intensity and color temperature. For this we need the tools discussed in this module.
Light intensity (quantity) is measured in foot-candles in the United States, or in lux in most other countries.
Even in the United State slux seems to be replacing foot-candles.
As we've noted, a foot-candle equals about 10.74 lux (or, for a rough conversion, multiply foot-candles by 10
to get lux). To provide some points of reference: sunlight on an average day ranges from 32,000 to 100,000
lux TV studios are lit at about 1,000 lux, a bright office has about 400 lux, moonlight represents about 1 lux,
starlight measures a mere 0.00005 lux.
In typical lighting setups, lighting instruments serve four functions:
 key lights
 fill lights
 back lights
 background lights
We'll have a series of examples that shows this formula in action. If
you study this photo you may detect four light sources:
 one on the left (the key light )
 one of the right (a much dimmer fill light )
 one on the hair (a back light ),
 one on the background (a background light )
Key Light
As the name implies, the key light is the main light. The key light highlights the form, dimension and surface
detail of subject matter. In terms of coherence or quality the key light should be in the middle of the hard-tosoft range. In three-point (formula) lighting the key light is placed at an angle of between 30- and 45-degrees
from either the left or the right of the camera. Forty-five degrees off to one side is best because, among other
things, it brings out optimum texture and form (dimension) in the subject. For the sake of consistency, the 45degree angle will be used throughout this discussion.
Fill Light
The purpose of the fill light is to partially (but not entirely) fill in the shadows created by the horizontal and
vertical angles of the key light. Ideally, the fill light should be about 90 degrees away from the key light.
This means that if you draw lines from the key to the subject and then to the fill light, you'll create a right
angle. Although the horizontal angle for the key should be about 45 degrees, the vertical angle of the fill is less
critical. Generally, the fill is placed just above the camera, which means it ends up being slightly lower than the
key. In this position it can easily do what it's intended to do: partially fill in the shadows created by the key
light.
Back Light
The function of the back light is to separate the subject from the background by creating a subtle rim of light
around the subject. The back light, sometimes called a hair light, should be placed directly behind the subject
in relation to the close-up camera. From an overhead perspective you should be able to draw a straight line
from the lens of the close-up camera, through the subject, directly to the back light.
Lighting Quiz
1. A soft light source placed close to the camera
minimizes surface detail The effect is commonly
referred to as
a. flat light
b. Hard light
c. Soft light
d. Coherence
2. A light casts a sharp, clearly defined shadow
a. flat light
b. Hard light
c. Soft light
d. Coherence
3. Light tends to hide surface irregularities and
detail
a. flat light
b. Hard light
c. Soft light
d. Coherence
4. Used over the front of a light to soften and
diffuse their beams
a. Diffuser
b. Fill light
c. Screen
d. Foot candle
5. The hardness or softness of light is referred to
as?
a. flat light
b. Hard light
c. Soft light
d. Coherence
6. Average daylight color temperature – 5400k
a. 3600 K
b. 3200 K
c. 5400 K
d. 5600K
7. undesirable scene-to-scene technical
inconsistency is referred to as a ____ problem
a. technical continuity
b. color temperature
c. lux
d. Foot candle
8. color temperature of standard studio lighting.
a. 3600 K
b. 3200 K
c. 5400 K
d. 5600K
9. Unit of light intensity used in the United States
– foot candle
a. technical continuity
b. color temperature
c. lux
d. Foot candle
10. Unit of light intensity used in most countries.
a. technical continuity
b. color temperature
c. lux
d. Foot candle
11. The purpose of the ____ is to reduce (but not
eliminate) the shadows created by the
horizontal and vertical angles of the key light.
a. fill light
b. flood light
c. back light
d. key light
12. The function of the ___ light is to separate the
subject from the background by creating a
subtle rim of light around the subject.
a. fill light
b. flood light
c. back light
d. key light
13. As the name implies, the _____________ is the
main light. The __________ highlights the form,
dimension and surface detail of subject matter.
a. fill light
b. flood light
c. back light
d. key light