MODULE 2 GRAZING – light strikes a surface at a sharp
angle, reveals texture, emphasize flaws and
LIGHT AND LIGHTING FUNDAMENTALS
unevenness in surfaces.
LIGHT WALL WASHING – light strikes a surface at a
-Visually evaluated radiant energy wide angle, even lighting on vertical space.
-Form of energy, transmitted by radiation-human eye is SILHOUTTE – light used to illuminate
sensitive to background, reveals outline of objects.
Newton: All heated bodies emit energetic corpuscles, each UPLIGHT – light source below an object,
having the same very high velocity and a size dependent produces shadows reversed how an object is
upon its color; postulated to travel in straight lines and shadowed in daylight, eerie/unnatural effect.
could be reflected and refracted. Ideal direction of lighting:
Huygen: Every point on an advancing wavefront serves as Should be determined by the space function or tasks
a source of secondary wavelets, sent out radially
Shadows at a work task may be irritating.
Maxwell & Hertz: Showed that all radiant energy consists
of electromagnetic waves travelling at the velocity of Excessive concentration and constant readaptation of the
light. eye can cause visual fatigue and a loss in performance or
increase in accidents.
Sun – best natural source of light
Highlights and shadows must be used sparingly depending
380-770 nm – wavelength, visible portion of on the task to prevent the introduction of negative factors.
electromagnetic spectrum.
Highlights and shadows, on the other hand, provides a
Incandescent – produces light with greater amounts of pleasant visual environment located away from the major
power in longer/warm wavelength/spectrum. tasks.
VISIBLE LIGHT SPECTRUM: 2. COLOR – defined with a variety of metrics, 2
Violet: 390 - 455 nm most common are:
-Correlated Color Temperature (CCT)
Blue: 455 - 492 nm -Color Rendering Index (CRI)
Green: 492 – 577 nm
Correlated Color Temperature (CCT)
Yellow: 577 – 597 nm -Relative whiteness of a light source
-Whether the source appears warm, cool or
Orange: 597 – 620 nm neutral
Red: 620 – 780 nm -Measured in KELVIN (K)
-Range of CT indoors: between 2500-5000K
Subtractive primaries – basis for the development of all -First criterion considered in the development
manufactured paints and dyes. of a space’s image
-CCT of a lamp refers to the absolute
Additive primaries – what the eye uses in the process of
temperature of a blackbody when its visible
seeing light and color.
radiation most closely matches the color of the
FACTORS THAT CAN BE CONTROLLED IN THE lamp.
DESIGN OF A LIGHTING SYSTEM: -Major mood-setting element of the space -
Warm color helps to create an intimate or cozy
DIRECTION, COLOR, BRIGHTNESS, & QUANTITY space
1. DIRECTION – Can enhance and emphasize -Cool color associated with a business like
an object’s perceived shape or form. environment
Techniques used: CRI RATING – how well an object’s colors
are rendered by a source.
KEY – single point source of light, provides
-comparison of 8 specific test colors under an
highlight and casts shadows, contrast, & definite
ideal light source in question
focus.
-When color rendering is important, a source
FILL LIGHTING – multidirectional/ diffuse light, with a high CRI (e.g. 3500°K fluorescent with
reduces shadows, creates a cloudy day feeling. a CRI of 85) should be selected
-If not important, a CRI in the mid 70s is less
expensive and may meet the client’s needs
-If extremely important, a CRI in the 90s may
be recommended
