Lighting Flashcards
What is called the alteration of the natural quantity of light in the night environment due to the introduction of excess artificial light?
Light pollution
It is the clear transparent bump on the front of the eye that does about two-third of focusing of light.
Cornea
It is the colored part of the front of the eye. The function of the ____ is the adaptation of vision from light to dark, and vice versa.
Iris
It is the small opening in the center of the iris where light enters the lens. It appears black because all of the light that enters is absorbed inside the eye.
Pupil
It is variable in shape and can focus objects at various distances on both its front and back surfaces. It is more curved in the back than in the front.
Lens
It fills the space between the lens and the cornea.
Aqueous Humor
It is continuously being produced and the surplus escapes through drain tube
Canal of Schelemm
Blockage of the drain tubes results in increased pressure in the eye
Glaucoma
It is a clear jelly-like substance that fits the large space between the lens and the retina. It helps to keep the shape of he eye fixed and is essentially permanent.
Vitreous Humor
It is the tough, light, tight covering over all of the eye except the cornea. It is protected by a transparent coating called the conjunctive
Sclera
The light-sensitive part of the eye. It converts the light image into electrical nerve impulses that one sends to the brain. It’s lining the most sclera.
Retina
Energy can neither be created nor destroyed, only altered in form
Law of Conservation of Energy
Basic unit of light
Photons
Travels 2,998 x 10^8 m/s in vacuum
Photons
120 million in each eye in most of the retina.
Rods (in the retina)
Maximal sensitivity at 510 nm (blue-green light) and sensitive to darker colors
Rods (in the retina)
6.5 million in each eye used for day light
Cones (in the retina)
Maximal sensitivity at 550 nm (yellow-green)
Cones (in the retina)
Documented during the day
Photopic Vision Regime
Documented in the middle of the day
Mesopic Vision Regime
Documented during the night
Scotopic Vision Regime
The projection neurons of the vertebrate retina, conveying information from other retinal neurons to the rest of the brain
Ganglion Cells
Circadian receptors
Ganglion cells
Peak sensitivity at 484 Nanometer in blue spectral range
Ganglion cellls
It controls the circadian rhythm
Photoreceptor
It is the measure of the power of visible light produced by a light source of light fitting. Measured in lumens (lm)
Luminous flux
Expressed in lumens
Luminous flux
Part of the power is perceived as light by the human eye
Luminous flux
Expressed in candela
Luminous intensity
Expressed directionally if visible light from a light source
luminous intensity
Expressed in lumens/meter-squared
Illuminance
Expressed in candela/meter-squared
Luminance
Amount of light that perceiver receives
Luminance
Expressed in watts or J/s
Radiant flux
Energy per unit of time that is radiated from a source over optical wavelengths, which includes the electromagnetic spectrum
Radiant flux
Expressed in watts/steridian or w/st
Radiant intensity
The emitted radiant flux per solid angle
Radiant intensity
Expressed in E Radian Existence (W.sq.m)
Irradiance
Power per unit area of electromagnetic radiation incident on a surface
Irradiance
Expressed in W/SR
Radiance
Is the radiant flux emitted, reflected, transmitted or perceived by a given surface
Radiance
Who demonstrated that electric and magnetic fields travel through space as waves move at the speed of light?
James Clerk Maxwell
Who derived and provided the mathematical computation to light?
James Clerk Maxwell
Luminous flux/angle of incidence =
Luminous intensity
Luminous flux/area of reflected surface =
Illuminance
Luminous intensity / (area of ref. surface)(cos e) =
Luminance
(Illuminance)(p) / pi
Luminance
Measures how well a light source produce visible light
Luminous Efficacy
Spatial distribution of luminous flux or lumens per steridian
Luminous Intensity
Total luminous flux density leaving a surface irrespective of directivity or viewer position
Exitance
The ratio of energy reflected the total energy incident on a body, expressed in percentage.
Reflectance (Φ=Φr+Φa+Φt)
Associated with psychological and physiological effects
Visual Comfort
Involves eye fatigue and can lead to headaches and neck and shoulder pain
Visual discomfort
The phenomenon is caused by extremely bright light sources or by strong brightness contrast in the visual field.
Glare
Perpetual sensation caused by a luminous source or reflecting surface
Brightness
What is called being blinded by brightness such as headlight?
Disability glare
What do you call psychological glare?
Discomfort glare
Cause of glare: Light source in the field of view
Direct glare
Cause of glare: Reflection of a light source
Reflected glare
Ideal angle of light
45 degrees
A metric used to predict discomfort glare in interior applications and considers the direct light component
Unified Glare Rating (UGR)
First metric which considered large glare sources (e.g. the sky viewed through the window)
Daylight glare index (DGI)
Calculations require both direct and diffuse luminaires
CIE Glare Index
CIE stand for _____________________________. Also for luminaire source of glare
International Commission in Illumination or Commission internationale de l’éclairage)
Massive system of equations adopted by IESNA. Only valid for typically-sized luminaires of light (no halogens or visible skies)
Visual Discomfort Probability (VCP)
IESNA stands for ___________________
Illuminating Engineering Society of North America
Glare sources are detected by contrast ratios, so direct daylight and specular reflections are considered.
Daylight Glare Probability(DGP)
Formula for Daylight Factor (EI)
EI = Sky Component (SC) + Externally Reflected Component (ERC) + Internally Reflected Component (IRC)
-Subdivided into outdoor and indoor.
-Bright, powerful illumination that lights up a room in its entirety.
Ambient Lighting
Also known as General Lighting
Ambient Lighting
To provide you with uniform levels of illumination over the entire space completely independently from other lighting sources
Ambient Lighting
Serve as a more worthy addition than effective task lighting specifically tailored for the task you are about to complete.
Task Lighting
Achieving a specific desired effect by using certain points of interest is what this type of lighting does best
Accent Lighting
Create an impression of a larger room, highlight a certain feature or decoration focal point such as a beautiful collection or even a unique piece of art
Accent lighting
This type of lighting shines three times as much light on the focal point as ambient lighting provides to emphasize it
Accent lighting
Have a higher output and narrower beam angle to focus the light only where required
Accent Lighting
He was one of the pioneers of and considered the father of architectural lighting design. He first opened his firm in 1935, working on architectural and theatrical lighting.
Richard Kelly (1910-1977)
Richard Kelly identified the three (3) form of light play:
1._____________
2._____________
3._____________
Focal glow, ambient luminescence, play of brilliants
Creating focus and interest
Focal glow
Minimizing the importance of certain elements, general lighting, achieved by light colored walls, curtains and ceilings
Ambient Luminescence
Stimulating the optic nerves and curiosity. It can be entertaining
Play of brilliants
Uniform and generally diffused lighting
General lighting
Small, high-level area of lighting without contributing to the general lighting and supplements the general lighting
Local & Supplementary Lighting
The ceiling and upper walls become the primary light source which creates shadowless environments. The resultant illumination is generally uniform and direct and reflected glare are low.
Indirect lighting
It has the greater portion of the light beamed downwards. Wall sconces with an opalescent glass globe are an example.
Semi-direct lighting
This light is mostly reflected, but some parts of the light source also provide a smaller amount of direct light. Most of this light is beamed upwards
Semi-indirect lighting
Generally the equal amount of upward and downwards lights and global in shape.
General diffuse lighting
__________ tend to give lighter illumination while walls may be less illuminated in direct-indirect lighting.
General diffuse lighting
__________ have a little horizontal component in contrast to general diffuse lighting.
Direct-indirect lighting
____________ has the greater portion of the light beamed downward. Wall sconces with an opalescent glass globe are an example.
Semi-direct lighting
Does not illuminate the ceiling. It can be spread (surface-mounted) or concentrated (downlight used alone where a privacy type of atmosphere is needed)
Direct lighting
The light distribution pattern is spread uniformly over a large surface area. This allows a higher spacing to mounting height ratio (it can be spaced farther.) Usually achieved by using lenses.
Prismatic distribution
Provides uneven illumination and requires closer spacing for uniform illumination. This distribution is usually achieved by parabolic louvers (eggcrate-like)
Parabolic distribution
A type of lamp where the heated wire filament produces light.
Incandescent lamps
A thin metal with a high melting point that glows or produces visible light with a current passing through.
Filament (Tungsten filament)
What are the gasses inside incandescent bulbs?
Nitrogen, neon, argon
A family of artificial light sources that emit light by sending an electrical discharge through an ionized gas i.e. plasma
Gas-discharge lamps
A type of lamp where light is produced by passing the electric current through a semiconducting material (a diode) which emits photons (light) through the principle of “electroluminescence”
LED (light emitting diodes) lamps
This is produced by cathodoluminescence i.e., by a beam of electrons made to hit a fluorescent phosphor surface.
Electron-stimulated Luminescence (ESL) Lamps
A metric that looks at specific light levels at a set day and time using localized weather conditions to review lighting design and glare.
Point-in-Time Radiance Simulation
The quality of light emitted by a source that falls on a surface.
Illuminance
It is wasted light that performs no function or task.
Light pollution
Most common in homes. It uses electric current to heat a tiny coil of tungsten metal inside a glass bulb to produce light.
Incandescent
Used mostly in commercial settings. It produces light when electric current is conducted through mercury and inert gases.
Fluorescent
3 to 4 times more efficient than incandescent, lasts 10 times longer
Fluorescent
Used mainly for large-area applications. Provide higher efficacy and longer service life. Most common types are mercury vapor (MV), metal halide (MH), and high-pressure sodium (HPS)
High-Intensity Discharge
Also considered a high-intensity discharge lamp, but it has some unique characteristics. Used in outdoor applications and the most efficient form of artificial lighting.
Low-Pressure Sodium
Used for streets, car parking, cycle tracks and pedestrian areas
Column mounted fittings
Used most commonly for security
Wall mounted lanterns
used for pathway and area lighting
Lighting bollards
Used for pathways, or where buried in the ground for up lighting structures, trees, and other incidents
Recessed fittings
The art of placing apertures into buildings to control either direct or indirect sunlight that penetrates the space to provide interior lighting.
Daylighting
An annual illuminance metric that describes multiple categories of “usable” lux levels in a space, reporting a percentage of floor area that falls within a specified illuminance range for 50% of the time.
Useful Daylight Illuminance
A measure of annual daylight sufficient for a given area, reporting a percentage of floor area that exceeds a specified illuminance level for a defined analysis period.
Spatial Daylight Autonomy (sDA)
_______ is not a glazing panel. It is stronger, lighter, and more energy efficient than look-alike and alternative products
Translucent fiberglass reinforced polymer (FRP)
Is the ability of a product to be perpetually cycled/upcycled.
Circularity
It is a traditional composition used because of its performance profile. It is composed of a polyester core for strength and flexibility, and a vinyl jacket for durability and cleanability.
Vinyl-coated polyester
What does FLAP in terms of Bird Effects means?
Fatal Light Awareness Program
Formula for Daylight factor:
DF=100 x EI(interior)/EO(exterior)
What do you call the light reflected from an exterior surface and then reaching the point considered?
Externally Reflected Component (ERC)
An SOP metric that equates to the density of the weave of the shade cloth material
Openness Factor
A DF under ___ will feel gloomy
2%
In hospitals, these materials are discouraged from being used inside.
Formaldehyde, Polyvinyl Chloride, and
Perfluorinated Chemicals
A certification that focuses on the effects building has on human health and well-being
WELL
What angle of light distribution is considered to cause direct glare in rooms with an average ceiling?
90 degrees
What angle of light distribution is considered to cause direct glare in rooms with an high ceiling?
60 degrees
As of the 21st Century, humans now spend approximately how much of their time indoors?
90%
A DF over _____ could result in a design that is overglazed, causing too much heat gain or heat loss.
5%
Why is gray the most popular color for shade cloth?
It gives a clearer view than white fabric
A certification that helps manufacturers create and buyers identify interior products and materials that have low chemical emissions.
GREENGUARD
What Vitamin do you get from sunlight?
Vitamin D
Oldest way of allowing natural light into a building. Its transparency offers unparalleled visual freedom with the inherent biophilic advantages of linking people to nature.
Glass
The glow effect that can be seen over populated areas.
Sky glow
Light that go across property lines and illuminates someone else premises
Light trespass or nitrous pass
Direct light from a patch of sky visible at the point considered
Sky component
Light entering the window but reaching the point only after reflection from an internal surface
Internally reflected component (IRC)
Formula for Interior Illumination (Ei)
Ei = SC + ERC + IRC
____________ allow occupants to control shades via a wall switch or a remote control and can be integrated with lighting systems
Motorized roller
- This type of fabric filter sunlight and preserve the view. Openness factors are typically 3 to 5%.
- Applications in lobby spaces and open office design
Sheer fabrics
- This type of fabric permit limited light into the interior space and limit the view. Openness factor ranges from 1 to 3%, which also impacted by material color.
- Applications are in private offices, patient rooms, and spaces that require some degree of privacy
Semi-opaque fabrics
This type of fabrics are opaque and block out all the light and the view. Openness factor is 0%
Blackout fabrics
Formula for Luminous intensity
Lum. flux / angle of incidence = lum. intensity
Formula for illuminance
lum. flux / area = illuminance
formula for luminance
lum. intensity / (area)(cose e) - luminance
formula for luminance
(illuminance)(p^) / pi = luminance
