Transcript 10.1 Wave model of light

10.1 Wave model of light
Colour Theory
Wave Model of light
Remember: Light waves transfer energy
 Light moves outward in all directions
from its source

Colour
White light is a combination of several
colours
 A prism is transparent glass or plastic
with flat, polished sides
 A prism will separate white light into all of
the colours of the visible spectrum
(ROYGBIV)

Colours
Each colour has a
different wavelength
 Red has the longest
wavelength, lowest
frequency
 Violet has the shortest
wavelength, highest
frequency

Additive Colour Theory

Colours of light are NOT the same
as pigments you work with in art
 Primary colours for light: RED,
BLUE, GREEN
 Mixing the primary colours of light
mix to give white light
 Mixing only two of the primary
colours results in the secondary
colours: CYAN, YELLOW,
MAGENTA
How do we see colour?
When light strikes an object, some
wavelengths are reflected (bounce off an
object) while others are absorbed
 The reflected wavelengths are the
colours we see

Subtractive Colour Theory

Coloured matter selectively absorbs different
colours or wavelengths of light. These colours
are “subtracted” from the reflected light that we
see
 Black absorbs all colours
 White reflects all colours
 Primary colours: CYAN,
YELLOW, MAGENTA
WHEN THESE ARE MIXED,
BLACK IS PRODUCED!
Subtractive Colour Theory
This theory applies to pigments and the
colours they absorb (LIKE ART CLASS)
 Primary colours: CYAN,
YELLOW, MAGENTA
WHEN THESE ARE MIXED,
BLACK IS PRODUCED!
 Secondary colours: red, green, blue

Subtractive Colour Theory
Homework
p. 388 #1-5
p. 391 #1-5,8,10,11