Fundamentals of
TV Lighting
Miho Shirakawa
NHK
Broadcast Engineering Department
Content Production Engineering Center
(Production Engineering I)
training material ©NHK 2007
What is “LIGHTING” ?
LIGHTING is
Like
drawing pictures
with
light and shadow
example
Johannes Vermeer van Delft
“The Kitchen Maid”
training material ©NHK 2007
Classification of Lighting
Street Lighting
Office Lighting
Daily Life Lighting
Room Lighting
Signboard Lighting
LIGHTING
Television Lighting
Stage Lighting
Amusement Lighting
Movie Lighting
Photograph Lighting
training material ©NHK 2007
To Watch Something
Incident light
retina
lens
Optic Nerve
Reflected
Image
light
Object Eye
Brain
training material ©NHK 2007
Image on TV System
Eye Brain
LIGHT SIGNAL
LIGHT
SIGNAL
NHK
Camera Monitor
training material ©NHK 2007
For TV Lighting
Understanding of the Characteristics on
・ TV Camera
・ Light
training material ©NHK 2007
To know TV Camera
• Sensitivity
2000 lx / F8
• Resolution
1080i, 720p
• Others on each camera
Lens, S/N, etc.
training material ©NHK 2007
To Understand Light
① Visible Light
② Luminous Intensity
③ Illuminance
④ Color Temperature
⑤ Color Rendering Index
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White Light Spectrum
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Visible Light
380 nm 750 nm
training material ©NHK 2007
Luminous Intensity
The luminous flux emitted from a point per unit solid angle
into a particular direction.
Official base unit for light
1/683 [W/sr]
Intensity of illuminant
1 [cd] = 540×1012 [Hz]
training material ©NHK 2007
Illuminance
The total amount of visible light illuminating a point on
a surface from all directions above the surface.
at a point on a surface
Illuminant Object
[lx] illuminated intensity of a surface
training material ©NHK 2007
Illuminance (E)
I [cd]
θ
D [m]
Point
Source
Object
Surface
E = I cosθ / D2 [lx]
training material ©NHK 2007
Typical Illuminance Values
INSIDE OUTSIDE
PLACE [lx] PLACE [lx]
Living Room 300 - 700 Plain Sunshine ～105
Office Room 300 - 700 Cloudy Sky ～102
Operating Table 20,000 ～ Evening 1～10
Auditorium 70 - 150 Full Moon ～10-1
(theatre)
Half Moon ～10-2
Restaurant 300 - 700
Star Night ～10-3
Shop Front 1500 – 3000
イメージセンサの基礎
Cf. イメージセンサの 基礎と
基礎と応用, pp. 20
training material ©NHK 2007
Colour Temperature
The absolute temperature of a blackbody radiator
having a chromaticity equal to that of the light source
Black heated heated, heated, ・・・・・ heated
Body
The colour The colour
temperature is low. temperature is high.
training material ©NHK 2007
Correlated Colour
Temperature (CCT)
Standard
warmer Setting colder
[K] absolute zero temperature
training material ©NHK 2007
CIE Standard Illuminant
Illuminant A 2854 [K] tungsten lamp
Illuminant series C filtering illuminant A
Illuminant series D natural daylight
Illuminant series F Fluorescent lamp
CIE Standard Illuminant
Illuminant A
Illuminant D50 (5000 [K] for daylight and fluorescent lighting)
Illuminant D65 (6500 [K] for daylight and fluorescent lighting)
training material ©NHK 2007
CCTs of Illuminants
Illuminant [K]
Fire of Candle 1900
Studio Tungsten Lamp 3000 ～ 3200
Fluorescent Lamp 3200 ～ 7500
Metal Halide Lamp 5600 ～ 6000
Mercury Lamp 5800
Xenon Lamp 6000
training material ©NHK 2007
Natural Light
Illuminant [K]
Sunrise, Sunset 2000 ～ 3000
Plain Sunshine 5700
Summer Sunny Sky 5500 ～ 6500
Summer Shade 6000 ～ 7000
Overcast Sky 6800 ～ 7000
Clear North Sky 10000 ～ 20000
training material ©NHK 2007
Spectral Sensitivity Curve of
Illuminants
Incandescent
Relative energy
lamp
Daylight
（
％）
Metal halide lamp
ｎｍ]
ｎｍ
Wavelength [ｎｍ
training material ©NHK 2007
Correlated Color Temperature
(CCT)
CIE (1931) xy
chromaticity diagram
Wavelengths of
D65 monochromatic light are
shown in blue.
training material ©NHK 2007
CCT
CIE (1931) xy
chromaticity diagram
high colour low colour
temperature temperature
slight significant
change change
of CCT of CCT
training material ©NHK 2007
Mired
Mired (M) : micro reciprocal degree
106
M= [mired]
T [K]
T [K] color temperature
examples :
Blue Sky 25000 K 40 mireds
Flash (photos) 5000 K 200 mireds
training material ©NHK 2007
Colour Temperature Conversion
Daytime Evening
6300 K 3400 K
159 mired 294 mired
+135 mired
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Conversion at Studio
Daytime Evening
135 mired
Studio Tungsten Lamp 2232 K
3200 K
313 mired +135 mired = 448 mired
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Color Conversion Filter
A series :
Decrease in CCT
B series :
Increase in CCT
training material ©NHK 2007
Colour Conversion Filters
Filters of Tokyo Butaishomei CO., LTD
No. mired Conversion [K] No. mired Conversion [K]
A1 20 5500 → 5000 B1 -10 3200 → 3300
A2 40 5500 → 4500 B2 -30 3200 → 3500
A3 70 5500 → 4000 B3 -56 3200 → 3900
A4 100 5500 → 3600 B4 -81 3200 → 4300
A5 131 5500 → 3200 B5 -112 3200 → 5000
* See Each Specification.
* Mired values are not in common.
training material ©NHK 2007
Filter Attachment
Daytime Evening
135 mired
Tungsten Lamp
3200 K + A5
Filter
training material ©NHK 2007
Question
To mach a halogen lamp of
3200 K into the room with
fluorescent lamp of 4300 K,
which conversion filter should
be used?
training material ©NHK 2007
Allowable Range of CT
Human Eye TV Camera
NHK
5 mired 20 mired
training material ©NHK 2007
Allowable Range Chart
ILLIMINANT 3200 K 6500 K
SENSOR
Human Eye + 50 K + 200 K
5 mired - 50 K - 200 K
Film + 200 K + 500 K
10 mired - 100 K - 400 K
TV Camera + 250 K + 1000 K
20 mired - 200 K - 750 K
training material ©NHK 2007
A Red Apple?
Yes! Red Apple! It looks yellowish.
training material ©NHK 2007
Color Rendering
A characteristic of a light source on the color
appearance of objects, compared to natural light.
• Good performance in Colour Rendering
Ex. Tungsten Lamp
• Bad performance in Colour Rendering
Ex. Fluorescent lamp,
Mercury Lamp
training material ©NHK 2007
Color Rendering Index
(CRI)
A method for describing the effect of a light source on
the color appearance of objects, compared to a
reference source of the same color temperature.
Best Condition Poorest
CRI of 100 CRI of 0
low-pressure
incandescent sodium vapor
lamp lamp
training material ©NHK 2007
Illuminant Spectral Sensitivity
Incandescent Sodium
Sunshine lamp lamp
Quantum Efficiency [%]
Quantum Efficiency [%]
Quantum Efficiency [%]
Wavelength [nm] Wavelength [nm] Wavelength [nm]
training material ©NHK 2007
CRI
i : particular sample colour
4.6 : factor chosen that the Ra of a standard
warm-white Thalium lamp would be about 50
⊿Ei : distance
“Perfect” Source
CCT ≦ 5000 K : generally a black body radiator
CCT ＞ 5000 K : simulated daylight (e.g. D65)
training material ©NHK 2007
General Color Rendering Index
(Ra)
An averaged CRI of eight standardized colors chosen to
be of intermediate saturation and spread throughout
the range of hues.
training material ©NHK 2007
8 Test Colors for Ra
No. Colour appearance under
daylight CIE test color samples
1 Light greyish red
2 Dark greyish yellow
3 Strong yellow green
cf. JIS (Japanese Industrial Standard)
4 Moderate yellowish green
non-saturated colors 5 Light bluish green
evenly distributed over the 6 Light blue
complete range of hues
7 Light violet
8 Light reddish purple
training material ©NHK 2007
Extra Test Colors
To supply extra information
No. Colour appearance under
daylight CIE test color samples
9 Strong red
10 Strong yellow
cf. JIS (Japanese Industrial Standard) 11 Strong green
12 Strong blue
Our extra …
15 : Light Yellowish pink 13 Light yellowish pink
(human complexion)
(Japanese human complexion)
14 Moderate olive green
(leaf green)
training material ©NHK 2007
Example of Ra
Light Source Ra
Sun Light (zenith) 100
Tungsten Bulb 100
Halogen lamp 100
Metal Halide Lamp 70 - 96
White Fluorescent Lamp 61
High Colour Rendering Fluorescent Lamp 90 - 99
Low Pressure Sodium Lamp 0
training material ©NHK 2007
Missions
① Optimise Illuminance
② Balance Contrast
③ Correct Colour Balance
④ Appear Solidity
⑤ Express Texture
⑥ Express Feeling
training material ©NHK 2007
① Optimise Illuminance
Incident light
Adjustment
83 % 100 %
Object
Reflected NHK Signal
light
TV Camera
training material ©NHK 2007
Adjusted Signal
Signal Output
100 %
Reflectance
83 %
training material ©NHK 2007
Iris and Optimised
Illuminance
f/# = focal length / aperture diameter
f/# 2 2.8 4 5.6 8 11 16
Illumi-
nance 2000
[lx]
E = I cosθ / D2 [lx] Standard Camera
Sensitivity
training material ©NHK 2007
② Balance Contrast
training material ©NHK 2007
③ Correct Color Balance
• Color Temperature of Light Sources
Fluorescent Lamp?
Tungsten Bulb?
• White Balance of Camera
Reconstructed Image
of RGB signals
training material ©NHK 2007
Color Balance
Fluorescent
Correct Colour Balance Lamp
4000 K example
example 3200 K
Illuminant : Daylight
CCT : 5500 K Tungsten
Bulb
example
training material ©NHK 2007
④ Appear Solidity
Which does appear solidity?
Balance between Light and Shadow
training material ©NHK 2007
⑤ Express Texture
Juicy Pork Comparison with grains
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⑥ Express Feeling
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Hard shadow and soft shadow
Point light
Parallel light
Source of light
with narrow area
Source of light
with wide area
training material ©NHK 2007
