Colour

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Colour

• 8K Light

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(No Transcript)
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The colours of the spectrum

• Red
• Orange
• Yellow
• Green
• Blue
• Indigo
• Violet

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Red
Magenta
Yellow
White
Blue
Green
Cyan
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Adding colours

• White light can be split up to make separate
  colours. These colours can be added together
  again.
• The primary colours of light are red, blue and
  green

Adding blue and green makes cyan (light blue)
Adding blue and red makes magenta (purple)
Adding all three makes white again
Adding red and green makes yellow
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Seeing colour

• The colour an object appears depends on the
  colours of light it reflects.

For example, a red book only reflects red light
White light
Only red light is reflected
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A pair of purple trousers would reflect purple
light (and red and blue, as purple is made up of
red and blue)
Purple light
A white hat would reflect all seven colours
White light
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Using coloured light

• If we look at a coloured object in coloured light
  we see something different. For example,
  consider a football kit

Shirt looks red
White light
Shorts look blue
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• In different colours of light this kit would look
  different

Red light
Shirt looks red
Shorts look black
Shirt looks black
Blue light
Shorts look blue
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Using filters

• Filters can be used to block out different
  colours of light

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Questions (1)

• What is a prism?
• List the colours in the spectrum.
• How is a rainbow formed?
• What are the three primary colours in light?
• What are the secondary colours of light and how
  do you make them?

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Questions (2)

• Why do black objects appear black?
• At an evening football match it was decided to
  use green lights to make it look more exciting.
  If one side wore green and the other wore red,
  what colours would they appear in the green
  light?

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Questions (3)

• 5. Sam is wearing a white shirt, a red jacket and
  green trousers to a nightclub. What will his
  clothes look like
• a) in a red spotlight
• b) in a green spotlight
• c) in a blue spotlight?