Reflecting colour
I can explain the colour of an object in white light and in coloured light.
Reflecting colour
I can explain the colour of an object in white light and in coloured light.
Lesson details
Key learning points
- Colour is detected in the eye by the R, G and B ‘cone cells’ that each detect a range of colours of light.
- The colour of an object in white or coloured light depends on the amounts of R, G and B light it is reflecting.
- White objects reflect all colours of light so look the same colour as the incident light (whether white or coloured).
- The colours of light that an object does not reflect are absorbed. Black objects absorb all colours of light.
- In red/green/blue light, an object will appear red/green/blue if it reflects that colour, and black if it does not.
Common misconception
Colour is the sum of the colour of the object and the colour of light falling on it.
Use coloured lights to show that red coloured objects reflect red light, but not blue or green.
Keywords
Reflect - to hit a surface and ‘bounce’ off
Incident - a word used to describe the incoming light that hits a surface
Scatter - to reflect light in many directions at once
Cone cell - the cells at the back of the eye that detect colour
Absorb - a material that absorbs light / gains energy from light travelling through it, decreasing the amount of light
Equipment
For task B: a colour printed 'flag of Guyana', a source of green light e.g. a projector connected to a laptop to project a slide of green light
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
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Starter quiz
6 Questions
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