Lighting Flashcards
Transparent outer membrane surrounding the eye
Cornea
Two types of optic nerve receptors in the retina
Rods and cones
What is the purpose of the rods
Provide sensitivity to brightness, allowing us to see low levels of light
What is the purpose of the cones
Allow us to perceive finer details and distinguish colours
What are the factors affecting visibility?
Size, brightness, contrast, time
What is the range of wavelength visible light?
380-760 nanometers
What is the wavelength most visible to the human eye?
555 nanometers
Light is a special form of _________
Electromagnetic radiation
Term used to describe colour of light source
Colour temperature (chromaticity)
What is CRI?
Colour rendering index. Expresses the ability of a light source to portray the colour appearance of objects accurately when compared to a standard light source f the same colour temperature
Where are regular fluorescent lamps on the CRI?
Good/fair
Where are deluxe fluorescent lamps on the CRI?
Excellent/good
Where are incandescent lamps on the CRI?
Excellent. The top. CRI of 97.
Where are metal halides (400w) on the CRI?
Good.
Where are mercury Vapor’s on the CRI?
Poor
Where are HPS on the CRI?
Poor
Where are LPS on the CRI?
Very bottom. Undefined. Terrible.
Where are mercury Vapor lamps on the CRI?
Bottom. Poor.
Sort metal halide, LPS, HPS, mercury Vapor in the CRI.
Metal halide, HPS (deluxe), mercury Vapor (coated), HPS (diffuse coated), mercury Vapor (clear), LPS
Two fundamental measurements of light
Quantity, quality
The term for quantity of life and it’s unit
Luminous flux. Lumens.
The difference between luminous intensity and illuminance.
Luminous intensity: light emitted towards a specific direction within a given angle.
Illuminance: amount of light falling on 1m^2
What is efficacy?
Ratio of light output (lumens) compared to power input (watts) for a light source
1 watt produces _____ lumens
683
Two types of incandescent lamps
Carbon and Tungsten filament
Three factors contributing to quality of light.
Glare, diffusion, color.
Difference between a luminaire and lamp
Luminaire is the entire fixture including wiring and ballast, lamp is the bulb
The purpose of a luminaire
To provide an appropriate amount of light
Name the five classes of luminaires
Direct, indirect, semi indirect, semi direct, direct indirect
What type of lamps have a restrike time of 4-6 minutes?
Mercury Vapor
What type of lamp is this: passes current through a filament, heating it to glowing
Incandescent
What type of lamp is 5% useful energy and 95% heat loss?
Incandescent
What is the benefit of tungsten?
High melting point (over 3,000 degrees), and low rate of evaporation
About how many hours does an incandescent last?
1000
What bulb is code S?
Straight side. Looks like an Edison bulb.
What bulb is code F?
Flame. Looks like a flame.
What bulb is code G?
Globular. Round globe.
What bulb is code A?
Standard line. Think Standard A19’s
What bulb code is T?
Tubular. Fluorescent tube or cylinder bulb
What bulb is cide PS?
Pear shaped. Pear shaped standard
What bulb is code PAR?
Parabolic. Looks like the type in the bathroom vanity.
What bulb is code R?
Reflector. Larger parabolic, usually a flood light.
Bulbs 7.5w to 300w are ____ base
Medium
Bulbs 300w and larger are ____ base
Mogul
The two bases smaller than medium base.
Candelabra and intermediate.
Another name for the medium base.
Edison.
Low wattage and decorative bulbs usually have which type of base?
Candelabra or intermediate
What wattage are usually biposts?
500w or more
Do high or low wattage lamps have a higher efficacy?
High
T/F high filament temperatures produce greater efficacy
T
How do we slow the filament evaporation
40w and higher lamps are filled with inert gas
T/F tungsten halogen lamps provide a white light
True
What is the regenerative cycle?
The process preventing blackening on the inside of a lamp. Halogen gas.
How many hours do tungsten halogen lamps last?
2500-3000 hours
What wattage are usually tungsten halogen lamps?
300w, 500w, 1000w
Which lamps should you not touch?
Tungsten halogen