Lighting
in Films: Some Basic Introductory Points
1. Intensity–how bright the light source happens to
be, measured in watts or another kind of scale used for the same end,
such as footcandles.
2. Contrast–refers to the varying levels of
brightness and darkness within a particular scene. High
contrast here involves a scene with sharp contrast between bright and
dark areas within the scene, with little intermediation; low contrast
involves limited contrast between bright and dark areas within the
scene, with plenty of intermediation. The contrast range refers
to the ratio of the brightest to the darkest area within the one scene.
3. Character–refers to the color of light. The
color temperature of light sources is conventionally measured in
degrees Kelvin. Here’s a useful way to think about what
this means: as a black mass is heated it gives off light; as it heats
up it will turn glowing red, then orange, then white, and finally
blue-white; all of these changes can be measured in degrees
Kelvin. N.b. that in terms of color temperature, the lower
the color temperature the redder the light and the higher the color
temperature the bluer the light.
4. In shooting with film you need to compensate for
changes in color temperature by shooting with film that is color
balanced and/or with an appropriate filter to achieve the correct
balance. Video cameras usually allow for a certain range of
adjustment in and of themselves (by means of built-in filter wheels),
but also at times require use of (external) filters in particular kinds
of conditions with particular kinds of color temperatures.
5. Besides enabling color balance, lighting filters
can serve a number of other purposes depending upon their design: to
eliminate haze (haze filters) or to block out ultraviolet rays
(ultraviolet filters), to minimize reflections from water or glass
(polarizing filters), to scatter light and create a softer and less
detailed surface (diffusion filters), to turn any bright point of light
in the scene into a star pattern (star filters), to break up the light
yet scatter it into darker areas creating a fog effect (fog filters),
to reduce contrast and color saturation (low-contrast filters), and to
reduce contrast but preserve something of the color saturation at the
same time (soft-contrast filters).
6. Quality–usually described in terms of hard versus
soft, where a hard light has a narrow angle of illumination and
produces sharp, clearly defined shadows, whereas a soft light scatters
the light to create a much wider angle of gentle, diffused
illumination. Spotlights tend to produce harder light than
floodlights; spot lights of course narrow the concentration of where
the light is directed and upon what it falls, whereas floodlights
extend the concentration of where the light is directed and upon what
it falls far outward. The kind of artificial light source
also affects its quality. In general, the following scale
prevails:
From softer to harder:
Flourescent-Halogen-Tungsten-Flashlight-Strobe Light-Laserpoint Light
7. Further Ways of Controlling the Light–reflectors
bounce light into the scene from a bright light source whereas scrims
tend to reduce light intensity without changing the color
temperature. Screens block out light.
8. Arrangement of Lights. Classically,
film makers arrange lights according to a three-point
set-up. The strongest source of illumination, called the
key light, typically placed is balanced out by the fill light which is
typically placed on the opposite side of the camera-subject axis from
the key light. The fill light is not as intense, but it works to
fill in, at least somewhat, the shadows created by the key light.
The back light, usually placed above and behind the subject, helps
outline the subject and separate it from the background. Of
course, this is just the basic set-up, and usually many more lights are
employed as well, including eyelights which add sparkle to a person’s
eyes, background lights which illuminate the background but not the
back of the subject like the back light, and kicker lights which are
placed low and behind the subject, usually opposite the key light, to
help further separate, or ‘kick’, the subject out from the background.
9. High-key versus low-key lighting. High-key
lighting is generally quite bright, even illumination, with a minimum
of shadows. The key to fill ratio is relatively low (in terms of
relative intensity). Low-key lighting is generally quite dark,
often with much greater visible lighting contrast, and with pronounced
shadows. Some accounts suggest that high-key might be better
conceived of as high-fill because the fill light intensity is actually
high in relation to that of the key light, whereas low-key might, along
the same lines, be better conceived of as low-fill because the fill
light intensity is actually low in relation to that of the key
light. (It should be noted here that some accounts suggest that
high-key lighting simply refers to very brightly lit scenes, whereas
low-key lighting refers to very darkly lit scenes, and high-contrast
lighting refers to scenes which contains sharp contrasts between
brightly lit areas and darkly lit areas with little if any areas lit at
a level of intensity between the two.)
10. Direction or placement of lights: lighting from
the front tends to reduce shadows and flatten the image; lighting from
the side creates sharper shadows, especially with a hard light source,
while side lighting can also throw the subject into relief and
highlight texture with small shadows; backlighting emphasizes depth;
and lights angled from above or below create distinct, dramatic
shadows. Finally, a good way to recognize the angle and direction
of the key light versus a scene is to look for a catchlight, where a
reflection of the light sources is visible upon a reflective surface
such as a person’s eyes.