Light, Color, Lighting

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Light, Color, Lighting

• COM 112
• Beginning TV Production
• Volunteer State Community College

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Key Concept One (1)

• Lighting Means Deliberate Illumination and Shadow
  Control

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Overview

• Light - Directional and diffused light, light
  intensity and how to measure it, and contrast
• Shadows - Attached and cast shadows and falloff
  control
• Color - Additive and Subtractive Mixing, the
  color television receiver and generated colors,
  and color temperature and white-balancing

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Overview

• Lighting Instruments - Spotlights, floodlights,
  and studio and portable instruments
• Lighting Techniques - Operation of lights, the
  photographic or triangle lighting principle,
  field lighting and measuring illumination

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Two Basic Types of Light

• Directional - precise beam, focused which causes
  harsh, distinct shadows. Can be aimed without
  much spill area.
• Diffused - More general illumination. Spreads
  out quickly illuminating large area. No clearly
  defined shadows.

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Light Intensity

• How much light falls on an object or subject
• Measurements European - lux American -
  foot-candles
• Foot-candles to lux Multiply by 10
• Lux to foot-candles Divide by 10

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Some Light Intensity Issues

• Base light refers to overall light intensity.
  Light meters pointed from object to camera read
  either lux or foot-candles.
• With low light levels you should open f-stop..
  (lower number means more light)
• Light intensity can be increased by moving lights
  closer or farther from object

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Some Light Intensity Issues

• Light intensity can be decreased with diffusion
  material or increased by removing diffusion
  material
• Otherwise activate gain circuitry in camera, but
  note you will increase picture noise.

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Contrast

• Difference between brightest and darkest spots in
  a video picture
• Measured with light meter reading of reflected
  light
• 401 ratio is typical upper limit for TV camera

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Shadows

• Attached Shadows - appear affixed to an object
  and cannot be seen independent of it
• Help us perceive basic form, shape, and texture
  of an object

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Key Concept 2

• Attached shadows reveal form and texture

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Shadows

• Cast Shadows - Can be seen independent of the
  object causing them
• Help indicate location of an object relative to
  surroundings. Help orient the viewer

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Key Concept 3

• Cast shadows help us tell where things are and
  when events take place

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Falloff

• The degree of change from light to shadow
• Refers to relative abruptness or speed with
  which light area turns into a shadow area
• Fast Falloff - abrupt change from light to dense
  shadow. Can mean high contrast between light and
  shadow sides of a face
• Slow Falloff - gradual change from light to
  shadow

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Key Concept 4

• Falloff defines the contrast between light and
  dark areas and how quickly light turns to shadow.
• Computer generated lighting effects must
  compensate for synchronized shadows.

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Color

• Basic process of color mixing
• Color TV receiver and generated colors
• Color temperature and white balance

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Additive Subtractive Color Mixing

• Additive Primary Light Colors
• Red - Blue - Green
• Divided by Beam Splitter
• Mixed by adding one on another to make other
  colors
• Different colors made by varying intensity of one
  primary color with others

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Key Concept 5

• The additive primary light colors are red, green,
  and blue

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Additive Colors of Light
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Subtractive Color Mixing

• Red - blue- and yellow
• Done in paint or pigment by filtering out certain
  light colors

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The Color Television Receiver and Generated Colors

• Works on additive color mixing principle
• Theoretically the reverse of a camera
• Electron guns project red, blue and green beams
  on the TV screen

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Color TV Image Formation
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Color Temperature White Balancing

• White balance because of differing light color
  temperatures
• Relative reddishness or bluishness determined by
  color temperature
• Two light color standards (higher is more blue)
• Outdoor illumination 5600 degrees Kelvin
• Indoor illumination 3200 degrees Kelvin

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White Balancing

• Adjusting camera circuitry to reproduce white in
  the light color in which it is operating
• Important to color continuity between differing
  scenes
• Consumer cameras have auto white balance
• Studio cameras require manual white balance and
  achieve more precise balance

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Key Concept 6

• Color temperature measures the relative
  reddishness or bluishness of white light.
  Reddish white light has a low color temperature
  Bluish white light has a high color temperature.
• It has nothing to do with actual surface
  temperature.

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Lighting Instruments

• Two categories
• Spotlights throw directional light, a defined
  beam on a specific area with harsh, dense
  shadows.
• Floodlights non-directional diffused light
  creating transparent shadows with slow fall off.

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Types of Spotlights

• Fresnel step like lens w concentric circles
  creating differing lens thick nesses.
• Collects light into distinct beam w/ adjusted
  focus
• Studio workhorse lighting instrument
• Barn doors can provide additional light control

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Types of Spotlights

• Fresnel
• Size measured in wattage of lamps
• Common sizes are 1Ks (1,000 watts) and 2 Ks (2000
  watts)
• Can range from 500 watts to 5,000 watts
• HMI fresnels are expensive with high efficiency
  arc lamps at 5600 degree Kelvin and give 3 to 5
  times more illumination.
• Sometimes found on EFP shoots.

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Types of Spotlights

• Ellipsoidal Spotlight
• Special effects spotlight, with extremely sharp,
  high intensity beam which can be shaped by
  shutters
• The curved lens is focused by moving to or from
  the lighting instrument.
• Can accommodate patterned sheets for effects
  lighting

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Types of Spotlights

• Portable spotlights usually a combination
  spotlight and flood light.
• Very useful on ENG or EFP shoots
• Designed for light stand or clip on devices
• Low wattage units can be camera mounted

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Key Concept 7

• Spotlights produce a sharp, directional light
  beam with fast falloff.

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Floodlights

• No lens
• Create highly diffused, non-directional light
• Soft, transparent shadows (slow falloff)
• Common Types
• Scoop small, flexible, 3200 K, limited
  direction
• Softlight large open front with diffusing
  material
• Broad open rectangular front with 1-3 tube lamps

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Other Floodlights

• Fluorescent Bank extreme diffused light with
  low heat
• Strip or Cyc light illuminates cyclorama
  (seamless background.

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Key Concept 8

• Floodlights produce general, non-directional
  illumination. They have slow falloff.

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Lighting Techniques

• Operation of lights
• Studio lighting
• Field lighting
• Measuring illumination

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Lighting Safety

• Electricity always respect it
• Heat quartz generates heat
• Placing securing instruments dont hit anyone
• Light Beam no direct beam in eyes

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Key Concept 9

• Do not abandon safety for expediency

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Studio Lighting
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Key Concept 10

• The basic photographic principle, or triangle
  lighting (2 point model lighting) consists of a
  key light, a fill light and a back light.

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Application

• Fresnel spots usually used for key light above
  and 45 degrees left or right of subject
• Fresnel spots typically used for back light,
  opposite camera and directly above subject
• Floods used for fill light for slow fall off
  above and 45 degrees to the other side from key.

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Light Plotting

• Allows multiple triangles with dual uses
• Key for person 1 might serve as back light if
  subjects are seated opposite each other
• Light for what the camera will be shooting

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Key Concept 11

• The major criterion for good lighting is how it
  looks on the monitor.

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Field Lighting

• Outdoors w/ overcast is ideal for TV shooting
• Bright sunlight is high intensity spot. Produces
  extreme contrast. Can be a challenge. Youll
  need lots of fill light
• Indoors without windows Use reflectors if needed

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Key Concept 12

• In the field, light for visibility rather than
  artistic impact.

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Field Lighting Guidelines

• Scout Ahead
• Be Prepared
• Dont overload circuits
• Dont waste bulb life
• Secure light stands
• Move cords carefully

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Measuring Illumination

• Use light meter to measure
• Incident light light emitted by instruments
• Light meter in front of subject pointed toward
  camera
• Reflected light light reflected from objects or
  subjects
• Light meter close to and pointed at subject or
  object being lit.