The document discusses various aspects of lighting design including illumination, brightness, contrast, glare, diffusion, and color. It describes how lighting affects visual tasks and defines key lighting concepts. Specific lighting types and arrangements are also covered, such as downlighters, track lighting, and shade lighting. Proper lighting design considers factors like lighting level, uniformity, and control of glare to create a space that supports visual tasks and is comfortable for users.

1. ILLUMINATION

2. LIGHTING
LIGHTING FORM THE VERY BASIC FEATURE OF VISUAL ARCHITECTURE
AND INTERIOR DESIGN.LIGHT IS A RADIANT ENERGY AND IT RADIATES
EQUALLY IN ALL DIRECTIONS.
OUR ABILITY TO SEE WELL,TO JUDGE SHAPE ,COLOUR AND TEXTURE
,TO DIFFERENTIATE ONE OBJECT FROM OTHER OBJECT IS AFFECTED
NOT ONLY BY AMOUNT OF LIGHT AVAILABLE FOR ILLUMINATION BUT
ALSO BY OTHER FEATURE LIKE
BRIGHTNESS
CONTRAST
GLARE
DIFFUSION
COLOUR

3. BRIGHTNESS
BRIGTHNESS REFERS TO HOW MUCH LIGHT ENERGY IS REFLECTED BY A
SURFACE.
DEGREE OF BRIGHTNESS OF AN OBJECT IN TURN DEPENDS ON THE COLOUR
VALUE AND TEXTURE OF ITS SURFACE
A SHINY, LIGHT-COLOURED SURFACE WILL REFLECT MORE THAN A DARK OR
ROUGH TEXTURED SURFACE, EVEN THOUGH BOTH SURFACES ARE LIT WITH
THE SAME AMOUNT OF ILLUMINATION
TO DISCERN SHAPE ,FORM AND TEXTURE, SOME DEGREE OF CONTRAST OR
BRIGHTNESS RATIO ALSO REQUIRED.
EXAMPLE- A WHITE OBJECT CAN NOT BE SEEN ON WHITE BACKGROUND AS
IT WOULD BE SEEN ON DARK BACKGROUND.

4. CONTRAST
CONTRAST BETWEEN AN OBJECT AND ITS BACKGROUND IS REQUIRED
FOR VISUAL TASKS THAT REQUIRE THE DISCRIMINATION OF SHAPE
AND CONTOUR.
MAXIMUM RATIO OF 3:1 BETWEEN THE SURFACE AND ITS
BACKGROUND IS GENERALLY RECOMMENDED.HIGHER BRIGHTNESS
RATIO CAN LEAD TO GLARE AND ASSOCIATED PROBLEMS .

5. MAXIMUM RECOMMENDED BRIGHTNESS RATIO BETWEEN 1 AND 2 IS 3:1
MAXIMUM RECOMMENDED BRIGHTNESS BETWEEN 1 AND 3 IS 5:1

6. GLARE
ONCE OUR EYES HAVE ADJUSTED TO A CERTAIN LIGHTING LEVEL,ANY
SIGNIFICANT INCREASE IN BRIGHTNESS CAN LEAD TO GLARE,EYESTRAIN AND
IMPAIRMENT OF VISUAL PERFORMANCE
TWO TYPES OF GLARE
1. DIRECT GLARE
2. INDIRECT GLARE
DIRECT GLARE
CAUSED BY BRIGHTNESS OF LIGHT SOURCE
.BRIGHTER THE LIGHT SOURCE .GREATER THE GLARE
INDIRECT GLARE
INDIRECT GLARE IS CAUSED BY VIEWING SURFACE REFLECTING LIGHT FROM
A LIGHT SOURCE INTO THE VIEWER’S EYES.

7. GLARE
ONCE OUR EYES HAVE ADJUSTED TO A CERTAIN LIGHTING LEVEL,ANY
SIGNIFICANT INCREASE IN BRIGHTNESS CAN LEAD TO GLARE,EYESTRAIN AND
IMPAIRMENT OF VISUAL PERFORMANCE
TWO TYPES OF GLARE
1. DIRECT GLARE
2. INDIRECT GLARE
DIRECT GLARE
CAUSED BY BRIGHTNESS OF LIGHT SOURCE.BRIGHTER THE LIGHT SOURCE
.GREATER THE GLARE
INDIRECT GLARE
INDIRECT GLARE IS CAUSED BY VIEWING SURFACE REFLECTING LIGHT FROM
A LIGHT SOURCE INTO THE VIEWER’S EYES.

8. DIFFUSE
DIFFUSENESS IS A MEASURE OF LIGHT’S DIRCTION AND DISPERSION
AS IT EMANATES FROM ITS SOURCE
A BROAD SOURCE OF LIGHT SUCH AS LUMINOUS CEILING PRODUCES
DIFFUSED ILLUMINATION THAT IS FLAT, FAIRLY UNIFORM AND
GENERALLY GLARE FREE.
WHITE DIFFUSED LIGHTING IS USEFUL FOR GENERAL VISION

9. COLOUR
ANOTHER IMPORTANT QUALITY OF LIGHT IS ITS COLOUR AND HOW IT
AFEECTS THE COLOURATION OF OBJECTS AND SURFACES IN ROOM.
DAYLIGHT RANGE FROM PURPLE TO RED .
SPECTRAL DISTRIBUTION OF ARTIFICIAL LIGHT SOURCE VARIES WITH
THE TYPE OF LAMP
EXAMPLE-
INCANDESCENT BULB PRODUCES A YELLOW WHITE LIGHT
FLUROSCENT PRODUCES BLUE WHITE LIGHT.
APPARENT COLOUR OF SURFACE IS RESULT OF ITS REFLECTION OF ITS
PREDOMINANT HUE AND ITS ABSORPTION OF THE OTHER COLOUR
OF THE LIGHT ILLUMINATING IT.

10. NATURAL LIGHTING IS LIGHT AVAILABLE IN NATURE.WE PERFORM
ALL OUR DAILY ACTIVITIES IN THIS DAYLIGHT.
DAYLIGHT IS NOTHING BUT SUN LIGHT ON EARTH.
INTENSITY OF SUNLIGHT VARIES DEPENDING ON ATMOSPHERIC
CONDITION.
SUNLIGHT IS BRIGHT IN MORNING ,DULL IN EVENING.ITS
BRIGHTNESS MORE IN THE AFTERNOON CAUSING GLARE
NATURAL LIGHTING

11. DAYLIGHT FACTOR
THE DAYLIGHT FACTOR (DF) IS A MEASURE OF NATURAL DAYLIGHT IN A
SPACE.
IT QUANTIFIES THE AMOUNT OF LIGHT AT A GIVEN POINT IN A SPACE
RELATIVE TO THE SIMULTANEOUS AMOUNT OF DAYLIGHT AVAILABLE
OUTSIDE.
A DF OF 2 PER CENT WOULD MEAN THAT THE INDOOR DAYLIGHT IS 2 PER
CENT OF THE AVAILABLE OUTSIDE DAYLIGHT, I.E., IF THE
OUTSIDE LIGHT IS 8,000 LX, THE INDOOR DAYLIGHT WOULD BE 160 LX. A DF
OF 1 PER CENT WILL PROVIDE A LOW
LEVEL OF LIGHT. A DF OF 2 PER CENT WILL BE AN "AVERAGE" DAYLIT SPACE. A
DF OF 4 PER CENT WILL BE PERCEIVED
AS A BRIGHT DAYLIT SPACE.“
NATURAL DAYLIGHT ILLUMINATION CAN VARY FROM 5,000 LX IN A HEAVILY
OVERCAST SKY TO OVER 40,000 LX IN DIRECT SUNLIGHT. THIS IS MUCH
GREATER THAN THAT NEEDED FOR ADEQUATE INDOOR LIGHTING. TYPICAL
INDOOR ILLUMINATION
REQUIREMENTS ARE LESS THAN 500 LX FOR WORKSPACES.

13. EXTERIOR SHADING
• A GOOD SHADING SYSTEM WILL PERMIT LOWER LEVELS OF
ARTIFICIAL ILLUMINATION TO BE SPECIFIED, BECAUSE THE EYE CAN
ACCOMMODATE ITSELF WITHOUT STRAIN TO FUNCTION WITHIN A
WIDE ILLUMINATION RANGE.
• EXTERIOR SHADING DEVICES ARE EFFECTIVE AT CONTROLLING
SOLAR GAIN. INTERIOR WINDOW SHADING WILL ALLOW MUCH
• SOUTH-FACING WINDOWS ARE THE EASIEST TO SHADE.
HORIZONTAL SHADING DEVICES, WHICH BLOCK SUMMER SUN AND
ADMIT WINTER SUN, ARE THE MOST EFFECTIVE.
• EAST- AND WEST-FACING WINDOWS ARE BEST SHADED WITH
VERTICAL DEVICES, BUT THESE ARE USUALLY HARDER TO
INCORPORATE INTO A BUILDING, AND LIMIT VIEWS FROM THE
WINDOW.

14. EXTERIOR SHADING

15. SKY EXPOSURE
• OUTSIDE OBSTRUCTIONS CAN REDUCE DAYLIGHTING POTENTIAL.
• THE SKY EXPOSURE ANGLE IS THE AMOUNT OF SKY THAT CAN BE
SEEN FROM A WINDOW. IT IS DEFINED AS THE VERTICAL ANGLE
OF SKY BETWEEN THE TOP OF AN OBSTRUCTION AND THE
VERTICAL, AND IS TYPICALLY MEASURED FROM A POINT TWO
METRES ABOVE THE FLOOR. THE
OBSTRUCTION

16. ARTIFICIAL
LIGHTING

17. ARTIFICIAL LIGHTING
ARTIFICIAL LIGHT SOURCES ARE OTHER SOURCES OF LIGHT WHICH
EVELOPED TO COMPENSATE FOR OR ASSIST THE NATURAL LIGHT. IT WILL
HAVE DIFFERENT FREQUENCIES AND WAVELENGTHS THAT DETERMINE THE
LIGHT COLOR.
ARTIFICIAL LIGHT SOURCES
ARTIFICIAL LIGHT SOURCES ARE CATEGORIZED BY THE TECHNOLOGY USED
TO PRODUCE THE LIGHT. THERE'S DOZENS OF SOURCES, WITH A FEW
COMMON IN HOUSEHOLD APPLICATIONS AND OTHERS MORE SUITABLE
FOR INDUSTRIAL USES. THE FIVE MOST COMMON LIGHT SOURCES ARE AS
FOLLOWS:
INCANDESCENT LAMP.
COMPACT FLUORESCENT LAMP.
FLUORESCENT TUBE.
DISCHARGE LAMPS.
LIGHT EMITTING DIODE (LED).

18. INCANDESCENT LAMP
UNTIL RECENTLY THE MOST
COMMON ELECTRIC LIGHT
SOURCE WAS THE INCANDESCENT
LAMP. THIS IS STILL WIDELY USED,
ALTHOUGH ITS RELATIVELY LOW
ENERGY EFFICIENCY IS LEADING
TO ITS REPLACEMENT BY OTHER
MORE EFFICIENT LAMPS SUCH AS
THE CFL.
A LARGE VARIETY OF SHAPES,
SIZES AND POWER IS AVAILABLE,
AS WELL AS DIFFERENT COLOUR
RANGES. TYPICAL LAMPS FOR
HOUSEHOLD USE RANGE FROM

19. INCANDESCENT LAMP
Characteristics:
Efficacy :10-20 Lumens/Watt
(Typically 13 lm/W for a 100W
GLS - General Lighting Service
lamp)
Lamp Life: 1000 hours.
(This increases dramatically on
reduced voltage)
Colour rendering: Excellent (1A)
Colour Temperature: 2700 K
(Warm)
Control: Fully dimmable (though
a shift to red occurs).
Advantages: Simple, compact,
good colour rendering, cheap to
install, instant light, no control
gear.
Disadvantage: High running cost,
short life, high heat output.
Applications: Domestic and short
duration use in commercial and
industrial installation. (e.g.
cleaner’s store).

20. Tungsten Halogen Incandescent Lamps
Characteristics
Efficacy 15-25 lumens/watt
(Typically 20 lm/W for a 300W linear
lamp)
Lamp Life: 2000 hours
Colour: Rendering: Excellent (1A)
Colour Temperature: 3000 K
Control: Fully dimmable (Though a
shift to red occurs).
Advantages: Instant, cheap to install,
excellent colour rendering.
Disadvantages: High running cost;
very hot operation;
Applications for Tungsten Halogen Lamps: Security lighting, vehicle lights,
short duration use e.g. T.H. are sometimes used alongside discharge lamps that
require a long warm up time. The T.H. lamps only operate whilst the discharge
lamps warm up. These lamps are particularly sensitive to a change in supply
voltage which affects their operating temperature.

21. COMPACT FLUORESCENT LAMP.
THE COMPACT FLUORESCENT LAMP (CFL) WAS DESIGNED AS A MORE
EFFICIENT REPLACEMENT FOR INCANDESCENT LAMP.
POWER RATINGS OF CFLS THAT CAN PROVIDE APPROXIMATELY THE
EQUIVALENT LIGHT OUTPUT TO INCANDESCENT LAMPS.

22. FLUORESCENT TUBE
FLUORESCENT TUBES ARE THE MAIN FORM OF LIGHTING FOR OFFICES
AND COMMERCIAL BUILDINGS.
THEY ARE A FORM OF GAS DISCHARGE LAMP, AND ARE FORMED IN A
LONG THIN GLASS CYLINDER WITH CONTACTS AT EITHER END THAT
SECURE THEM TO THE FITTING (OR LUMINAIRE) AND PROVIDE THE
ELECTRICAL CONNECTION.

23. DISCHARGE LAMPS
DISCHARGE LAMPS WORK BY STRIKING AN ELECTRICAL ARC BETWEEN
TWO ELECTRODES, CAUSING A FILLER GAS TO GIVE OFF LIGHT.
DIFFERENT METALS AND FILLER GASSES CAN BE USED TO PROVIDE A
RANGE OF COLOUR AND BRIGHTNESS.

24. LIGHT EMITTING DIODE (LED)
LEDS USE SEMI-CONDUCTORS TO CONVERT ELECTRICAL ENERGY DIRECTLY
INTO LIGHT. THEY ARE ONLY RECENTLY BECOMING AVAILABLE AS A LIGHT
SOURCE FOR LIGHTING PURPOSES, AND ARE HIGHLY EFFICIENT AND LONG
LASTING.
LED TORCHES ARE BECOMING VERY POPULAR, AS THEY PROVIDE A FAR
LONGER BATTERY LIFE THAN OTHER TYPES OF LIGHT SOURCE.

25. DIFFERENT TYPE OF LIGHTING ARRANGEMENT
• DIRECT LIGHTING
Angular fitting
Down lighter
Eyeball
Track lighting
Shade lighting
• INDIRECT LIGHTING
• DIFFUSED LIGHTING
• COMPOSITE LIGHTING
• CONCEALED LIGHTING

26. ANGULAR FITTING
IN THIS TYPE OF ARRANGEMENT ,THE LIGHT CAN BE TURNED AND
POINTED IN ANY DIRECTION.IT IS A COMFORTABLE TYPE OF LIGHTING
BECAUSE THE LIGHT IS ACTUALLY DIRECTED TOWARDS THE ACTIVITY LIKE
READING OR WRITING.

27. DOWN LIGHTER
SOURCE OF LIGHT IS
CONCEALED IN THE
CEILING.EVEN THOUGH
SOURCE OF LIGHT NOT SEEN
,LIGHT IS PROJECTED
DOWNWARDS WHEREVER IT
IS NEEDED TO PERFORM AN
ACTIVITY.DOWN LIGHTER
USEFUL FOR READING AND
OTHER ACTIVITY
PERFORMED AT AT A FIXED
PLACE IN ROOM.

28. EYEBALL FITTING
SIMILAR TO DOWN LIGHTER
BUT IT IS POSSIBLE TO
DIRECT THE LIGHT IN ANY
DIRECTION.
IT CAN LIGHT UP DARK
AREAS OF A ROOM AS IT
CAN BE DIRECTED IN ANY
DIRECTION.
IT HAS GREATER FLEXIBILITY
AND OCCUPIES LESS SPACE

29. TRACK LIGHTING
TRACK LIGHT IS VERY
POPULAR.IT IS VERY
EFFECTIVE AND DRAMATIC.
A SIMPLE TRACK IS WIRED
AND FITTED ON THE WALL
OR THE CEILING ACCORDING
TO THE NEED OF THE USER.
SPOTLIGHT CAN BE USED TO
ILLUMINATE A PAINTING OR
TO GET A SPECIAL EFFECT.

30. SHADE LIGHTING
SIMPLE AND ORDINARY
LIGHTING FOUND IN OUR
HOUSE.IT CAN BE FIXED TO
A WALL OR HANGED AT LOW
LEVEL LEVEL OVER A
TABLE.THE LIGHT SOURCE IS
COVERED BY A SHADE.IT IS
FIXED AND CAN NOT BE
MOVED OR DIRECTED
TOWARDS ANY
PLACE.SOMETIMES IT IS
POSSIBLE TO RAISE OR
LOWER THE SHADE.