Light_ Color_ Lighting

							             Light, Color, Lighting

COM 112 –
Beginning TV Production




 Volunteer State Community College
                Key Concept One (1)

• Lighting Means Deliberate Illumination
  and Shadow Control
                                   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
                                 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
           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.
                          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
         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
         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.
                                 Contrast

• Difference between brightest and darkest
  spots in a video picture
• Measured with light meter reading of
  reflected light
• 40:1 ratio is typical upper limit for TV
  camera
                                           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
                Key Concept 2

• Attached shadows reveal
  form and texture
                                       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
               Key Concept 3

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

• Basic process of color mixing
• Color TV receiver and generated colors
• Color temperature and white balance
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
                    Key Concept 5

• The additive primary light
  colors are red, green, and blue
Additive Colors of Light
           Subtractive Color Mixing

• Red - blue- and yellow
• Done in paint or pigment by filtering out
  certain light colors
    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
Color TV Image Formation
                    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
                     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
                             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.
                   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.
                    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
                     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.
                      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
                    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
                   Key Concept 7

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

• Fluorescent Bank – extreme diffused light
  with low heat
• Strip or Cyc light – illuminates cyclorama
  (seamless background.
                   Key Concept 8

• Floodlights produce general,
  non-directional illumination.
  They have slow falloff.
     Lighting Techniques
• Operation of lights
• Studio lighting
• Field lighting
• Measuring illumination
             Lighting Safety
• Electricity – always respect it
• Heat – quartz generates heat
• Placing & securing instruments
  – don’t hit anyone
• Light Beam – no direct beam in
  eyes
             Key Concept 9
• Do not abandon safety for
  expediency
Studio Lighting
                          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.
                         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.
                          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
                  Key Concept 11

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

• Outdoors w/ overcast is ideal for TV
  shooting
• Bright sunlight is high intensity spot.
  Produces extreme contrast. Can be a
  challenge. You’ll need lots of fill light
• Indoors without windows: Use reflectors if
  needed
                    Key Concept 12

• In the field, light for visibility
  rather than artistic impact.
     Field Lighting Guidelines
•   Scout Ahead
•   Be Prepared
•   Don’t overload circuits
•   Don’t waste bulb life
•   Secure light stands
•   Move cords carefully
                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.