Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Optometric Physics > Lecture 6 - What is Colour > Flashcards

Lecture 6 - What is Colour Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

What is colour

A

Wavelength of light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is wavelength

A

distance between 2 peaks on same wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is frequency

A

the number of complete waves generated per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is period

A

How long a wave takes to go through the full range of motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is light characterised by

A

Light is characterised by its wavelength or its frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Colour temperature

A
  • Thermal sources of light emit radiant energy in proportion to their temperature - commonly observed when piece of metal is heated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What happens when a piece of metal is heated

A

It changes colour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What colour does the metal glow when temperature increases and how

A

Red

Emit light - radiant energy - heat - glows red

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What colour is very hot

A

Blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a blackbody radiator

A

Perfect blackbody - theoretical object ( not exist in reality )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does a blackbody radiator do

A

ABSORB all radiation that falls on it - it would not reflect or transmit any radiation
Best emitter of radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Does a blackbody radiator absorb or reflect

A

Absorb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is an example of a blackbody radiator and why

A

Stars
Blackholes
Good at absorbing all wavelenghts, but not perfect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is property of something that is NOT a blackbody radiator

A
  • White/shiny silver surfaces
  • Worst absorbers
  • Poor emitters
  • Best reflecters
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Example of something that is NOT a blackbody radiator and why

A

Radiators

Painted white - infrared radiation is emitted gradually - poorly - emit heat slowly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Link between temperature and wavelength

A

Increase in temp = shorter wavelengths

As temp increases, there’s a shift in wavelengths emitted

17
Q

What is the shorter wavelength

A

Blue

18
Q

What can a blackbody be specified by

A

Its colour temperature

19
Q

What source is at a temp of 3000K

A

Warm white compact fluorescent and LED lamps

20
Q

What source is at a temp of 5000K

A

Cool white fluorescent lamps ( hotter temp but cooler )

21
Q

Colour temp and sensation link

A

Higher colour temp ( warmer ) - colder sensation

22
Q

What is CIE ( x,y) Colour Space

A

Specifies colours graphically using x,y co-ordinates

23
Q

If its closer to centre is it more or less saturated and what is the colour

A

Closer to centre - less saturated - white

24
Q

If its further from edges ( chart ) it more or less saturated

A

More saturated

25
Q

The co - ordinates x,y map the colour with respect to what

A

Hue and saturation

26
Q

What are the spectral colours

A

Correlated to a specific wavelength

27
Q

Where is the lines of purples located

A

Along bottom

28
Q

How can achromatic colour also be achieved

A

With many different mixtures of light

29
Q

What is additive colour mixing

A
  • Mixing of light
  • Superposition of RED, GREEN and BLUE lights
  • Almost all visible colours can be obtained by additive colour mixing of 3 colours
  • Involves primary colours
30
Q

What is cyan

A

Red

31
Q

What is magenta

A

Green

32
Q

What is tello

A

Blue

33
Q

Where is additive colour mixing used

A

Computer monitors

34
Q

What are the 3 primary colours and what colour do they produce when mixed

A

Red, green, blue

Produce white

35
Q

What is subtractive colour mixing

A

Colours created by partially/completely subtracting ( absorbing ) some wavelengths of light and not others

36
Q

Where is subtractive colour mixing used

A

Coloured pigments, dyes, paints, inks

37
Q

In colour printing what are usually the primary colours

A

Cyan, Magenta, Yellow and Black

Optometric Physics (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions